1,791 results on '"Esox"'
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2. The first Tertiary fossils of mammals, turtles, and fish from Canada's Yukon /
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Eberle, Jaelyn, Hutchison, J. Howard (John Howard), 1939, Kennedy, Kristen, Koenigswald, Wighart von, MacPhee, R. D. E., Zazula, Grant D., American Museum of Natural History Library, Eberle, Jaelyn, Hutchison, J. Howard (John Howard), 1939, Kennedy, Kristen, Koenigswald, Wighart von, MacPhee, R. D. E., and Zazula, Grant D.
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Dispersal ,Esox ,Fishes, Fossil ,Mammals ,Mammals, Fossil ,Miocene ,North America ,Paleoecology ,Paleontology ,Rhinoceroses ,Rhinoceroses, Fossil ,Turtles, Fossil ,Vertebrates, Fossil ,Whitehorse Region ,Yukon - Published
- 2019
3. Parvalbumin Gene: A Valuable Marker for Pike Authentication and Allergen Risk Assessment.
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Čermáková E, Mukherjee S, Nováková D, Horká P, Zdeňková K, and Demnerová K
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- Animals, Risk Assessment, Fish Proteins genetics, Fish Proteins immunology, Nucleic Acid Amplification Techniques methods, Real-Time Polymerase Chain Reaction methods, Humans, Food Contamination analysis, Biomarkers analysis, Molecular Diagnostic Techniques, Parvalbumins genetics, Parvalbumins immunology, Parvalbumins analysis, Allergens genetics, Allergens analysis, Allergens immunology, Food Hypersensitivity immunology, Esocidae genetics, Esocidae immunology
- Abstract
Fish from the pike ( Esox ) genus are valued in gastronomy for their superior meat quality. However, they can cause allergic reactions in sensitive consumers. This work aimed to fill the gap in the detection of pike allergens using molecular-biological techniques. New, fast, and accurate loop-mediated isothermal amplification (LAMP) and real-time PCR (qPCR) assays were designed to detect pike DNA using the parvalbumin gene as a marker. LAMP was assessed by electrophoresis, SYBR green optical detection, and real-time fluorescence detection. The latter was the most sensitive, detecting as little as 0.78 ng of pike DNA; the qPCR detection limit was 0.1 ng. The LAMP analysis took 20-70 min, which is significantly faster than qPCR. The study provides reliable detection and quantification of the parvalbumin gene in both fresh and processed samples and further highlights the versatility of the use of the parvalbumin gene for the authentication of food products and consumer protection via refined allergen risk assessment that is independent of the type of tissue or food processing method used.
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- 2024
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4. First Description of the Metacercaria of Nematostrigea serpens serpens (Nitzsch, 1819) (Trematoda, Strigeidae) and Phylogenetic Affiliation of Nematostrigea vietnamiensis Zhokhov & Mishina, 2011.
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Sokolov, Sergey G., Lebedeva, Daria I., Khasanov, Fuat K., and Gordeev, Ilya I.
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METACERCARIA ,TREMATODA ,ADULTS ,RIBOSOMAL RNA ,SUBSPECIES ,DIGENEA - Abstract
Background: The genus Nematostrigea comprises trematodes parasitising in fish-eating birds of Europe, Africa, and North America. Their life cycle is unknown. Purpose: To provide the first description of metacercariae of Nematostrigea serpens serpens, a nominative subspecies of the type species of Nematostrigea, and to record metacercaria of Nematostrigea vietnamiensis, with molecular data. Methods: Encysted metacercariae of N. serpens serpens and N. vietnamiensis were collected from fish in Russia and Vietnam, respectively, and were processed, identified, and documented using standard morphological techniques. The 28S rRNA gene of metacercariae of both species and the cox1 gene of metacercariae an earlier studied adult of N. serpens serpens were sequenced and used for phylogenetic analysis. Results: Metacercaria of N. serpens serpens have a spatulate body with a foliate forebody and a short hindbody, two long lateral rectilinear pseudosuckers, and the holdfast organ with bifurcated anterior and entire posterior external lobes. The analysis of the cox1and 28S rRNA gene sequences unequivocally showed the conspecificity of metacercariae and adult stage of N. serpens serpens. Based on the 28S rRNA gene sequence-based phylogenetic analysis, the genus Nematostrigea is a sister taxon to the group of strigeid genera Cotylurus + Ichthyocotylurus. Morphological and phylogenetic data demonstrated that N. vietnamiensis does not belong to the genus Nematostrigea and is possibly be affiliated with the crassiphialine trematodes. Conclusion: This is the first record of metacercariae of N. serpens serpens. N. vietnamiensis, renamed Prodiplostomulum vietnamiense comb. nov., must be moved to the crassiphialine 'Prodiplostomulum'-type metacercariae group [ABSTRACT FROM AUTHOR]
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- 2021
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5. Effect of feed restriction on fatty acid profile, body composition and selected blood parameters of intensive reared pike (Esox lucius).
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KUCSKA, Balázs, SZABÓ, András, BLAKE, Chris, HANCZ, Csaba, and VARGA, Dániel
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ESOX ,FATTY acid analysis ,FISH feeds ,BODY composition of fish ,ALKALINE phosphatase ,BLOOD testing - Abstract
This study investigated the effects of a six-week starvation period on the fatty acid profile, body composition and blood parameters of intensively reared pike (Esox lucius). 150 pike were stocked in an experimental recirculating aquaculture system (RAS) and feed was completely withdrawn. Body composition, fatty acid composition and blood parameters (serum protein, albumin, triacylglycerol, cholesterol concentration and Lactate dehidrigenase and alkaline phosphatase activity) were measured and somatic indices were calculated. A significant decline in bodyweight, crude fat content and somatic indices was accompanied by a significant decrease of blood triacylglycerol content. The relative proportion of saturated fatty acids in the fillet decreased, while polyunsaturated fatty acids increased. There was also a significant increase in the average chain length and unsaturation index of fatty acids found in the fillet flesh. [ABSTRACT FROM AUTHOR]
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- 2021
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6. Esox lucius Linnaeus 1758
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Çiçek, Erdoğan, Fricke, Ronald, Eagderi, Soheil, Sungur, Sevil, Coad, Brian W, and Hamdard, Mohammad Hamid
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Actinopterygii ,Esox ,Esociformes ,Esocidae ,Animalia ,Biodiversity ,Chordata ,Esox lucius ,Taxonomy - Abstract
Esox lucius Linnaeus, 1758 [N]—Northern pike Taxonomy. Original description: Esox lucius Linnaeus,1758:314 [Europe; possible syntypes:BMNH1853.11.12.114 (1, skin)]. Type catalog: Wheeler 1958:209].— Afghanistan synonyms: None.—Revisions: Berg (1948: 458).— Illustration: Berg (1948: 459, fig. 274). Status in Afghanistan. First record from Afghanistan by Berg (1948: 463); confirmed by Coad (1981: 8).— Afghanistan materials: None. Distribution and habitat. Distribution in Afghanistan: Pitnyak (Amu Darya River system, into Aral Sea).—General distribution:Circumpolar in Northern Hemisphere:North America, Europe, and northern Asia; widely introduced elsewhere.—Habitat: This species usually occurs in clear small lakes, shallow vegetated areas of larger lakes, marshes, creeks, and small to large rivers. It moves to deeper, cooler water in the summer. Spawning occurs in shallow flooded marshes associated with lakes, inlet streams to those lakes, or rivers; spawning habitat is basically a flooded area with emergent vegetation. Freshwater, brackish. Economic importance. Commercially important. Conservation. Conservation status in Afghanistan: Unknown.—IUCN: LC (NatureServe 2018).—Threats: No major threats are known.—Moderate sensitivity to human activities.—Keystone species.—Decline status: Stable.—Low priority for conservation action., Published as part of Çiçek, Erdoğan, Fricke, Ronald, Eagderi, Soheil, Sungur, Sevil, Coad, Brian W & Hamdard, Mohammad Hamid, 2023, Fishes of Afghanistan; a revised and updated annotated checklist, pp. 1-69 in Zootaxa 5305 (1) on page 42, DOI: 10.11646/zootaxa.5305.1.1, http://zenodo.org/record/8048564, {"references":["Linnaeus, C. (1758) Systema Naturae. Vol. 1. Ed. X. [Systema naturae per regna tria naturae, secundum classes, ordines, genera, species, cum characteribus, differentiis, synonymis, locis. Tomus I. Editio decima, reformata]. Impensis Direct. Laurentii Salvii, Holmiae, ii + 824 pp.","Berg, L. S. (1948) s. n. In: Ryby presnych vod SSSR i sopredelnych stan. [Freshwater fishes of the U. S. S. R. and adjacent countries]. Vol. 1. 4 th Edition. Opredeliteli po faune SSSR. [Guide to the fauna of the U. S. S. R.], Moskva. Freshwater fishes of the U. S. S. R. and adjacent countries No. 27. Russian Academy of Sciences, USSR, Moskva, 466 pp. [in Russian. English translation available, Israel Prog. Sci. Transl., Jerusalem, 1962, 504 pp.]","Coad, B. W. (1981) Fishes of Afghanistan, an annoted checklist. National Museum of Canada Publications in Zoology, 14, i - v + 1 - 26."]}
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- 2023
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7. Higher-order organisation of extremely amplified, potentially functional and massively methylated 5S rDNA in European pikes (Esox sp.)
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Radka Symonová, Konrad Ocalewicz, Lech Kirtiklis, Giovanni Battista Delmastro, Šárka Pelikánová, Sonia Garcia, and Aleš Kovařík
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rDNA ,Evolution ,Chromosome ,Fish ,Esox ,Single cell PacBio sequencing ,Biotechnology ,TP248.13-248.65 ,Genetics ,QH426-470 - Abstract
Abstract Background Pikes represent an important genus (Esox) harbouring a pre-duplication karyotype (2n = 2x = 50) of economically important salmonid pseudopolyploids. Here, we have characterized the 5S ribosomal RNA genes (rDNA) in Esox lucius and its closely related E. cisalpinus using cytogenetic, molecular and genomic approaches. Intragenomic homogeneity and copy number estimation was carried out using Illumina reads. The higher-order structure of rDNA arrays was investigated by the analysis of long PacBio reads. Position of loci on chromosomes was determined by FISH. DNA methylation was analysed by methylation-sensitive restriction enzymes. Results The 5S rDNA loci occupy exclusively (peri)centromeric regions on 30–38 acrocentric chromosomes in both E. lucius and E. cisalpinus. The large number of loci is accompanied by extreme amplification of genes (>20,000 copies), which is to the best of our knowledge one of the highest copy number of rRNA genes in animals ever reported. Conserved secondary structures of predicted 5S rRNAs indicate that most of the amplified genes are potentially functional. Only few SNPs were found in genic regions indicating their high homogeneity while intergenic spacers were more heterogeneous and several families were identified. Analysis of 10–30 kb-long molecules sequenced by the PacBio technology (containing about 40% of total 5S rDNA) revealed that the vast majority (96%) of genes are organised in large several kilobase-long blocks. Dispersed genes or short tandems were less common (4%). The adjacent 5S blocks were directly linked, separated by intervening DNA and even inverted. The 5S units differing in the intergenic spacers formed both homogeneous and heterogeneous (mixed) blocks indicating variable degree of homogenisation between the loci. Both E. lucius and E. cisalpinus 5S rDNA was heavily methylated at CG dinucleotides. Conclusions Extreme amplification of 5S rRNA genes in the Esox genome occurred in the absence of significant pseudogenisation suggesting its recent origin and/or intensive homogenisation processes. The dense methylation of units indicates that powerful epigenetic mechanisms have evolved in this group of fish to silence amplified genes. We discuss how the higher-order repeat structures impact on homogenisation of 5S rDNA in the genome.
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- 2017
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8. A review of Neogene and Quaternary pikes of southeastern Europe and a new species from the early Pleistocene of Nogaisk, Ukraine
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Oleksandr M. Kovalchuk, Mark V.H. Wilson, and Terry Grande
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Esociformes ,Esocidae ,Esox ,Miocene ,Pliocene ,Pleistocene ,Ukraine ,Russia ,Moldova ,Fossil man. Human paleontology ,GN282-286.7 ,Paleontology ,QE701-760 - Abstract
The fish genus Esox (Teleostei, Esocidae) has been recorded from thirty late Miocene, Pliocene, and Pleistocene localities where forty-one bone-bearing strata are exposed in the territory of Ukraine, Russian Federation, and Republic of Moldova. From eight localities the genus is reported or described for the first time. A detailed description and morphological analysis of the currently available osteological material demonstrates the presence of four species in the studied area: (i) Esox sibiricus (late Miocene–early Pliocene); (ii) Esox moldavicus (early Pliocene–early Pleistocene); (iii) Esox nogaicus sp. nov. (early Pleistocene, Calabrian); (iv) Esox lucius (early–middle Pleistocene). The Northern Pike (Esox lucius) is recorded for the first time in the early Pleistocene fossil record of southeastern Europe. The new species E. nogaicus is characterized by a massive dentary with deep symphysis and the possible presence of a pair of fixed canine-like teeth near the anterior end of the vomer. Such canine teeth are seen also in certain species known only from North America, the extant Esox masquinongy, the fossil species E. columbianus, and an unnamed Miocene form. However, unlike in E. nogaicus, in the three North American species fixed canines also occur anteriorly on the palatines. The Miocene, Pliocene, and Pleistocene pikes from southeastern Europe document a greater diversity of morphologies in the past than exists today in the pike species of Europe. Changes in the predominant species of Esox in southeastern Europe are hypothesized to be driven by changing global and regional climates.
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- 2017
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9. Coexistence of pike Esox lucius and brown trout Salmo trutta in Irish lakes.
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McLoone, Paul, Shephard, Samuel, Delanty, Karen, Rocks, Kieran, Feeney, Rory, and Kelly, Fiona
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ESOX , *SEA trout , *LAKES , *COEXISTENCE of species , *BIODIVERSITY - Abstract
An environmental study of pike Esox lucius recorded their presence in 522 Irish lakes and that they coexisted with brown trout Salmo trutta in 97 of these. Statistical models, accounting for spatial non‐independence among lakes, suggested that lakes with greater area, maximum depth and stream connectivity show a higher probability of coexistence. Introductions of E. lucius are likely to have negative effects on S. trutta stocks in small isolated lakes, but coexistence may be possible in larger systems. [ABSTRACT FROM AUTHOR]
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- 2018
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10. Sex‐specific effects of outbreeding on offspring quality in pike (Esox lucius).
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Sunde, Johanna, Tibblin, Petter, Larsson, Per, and Forsman, Anders
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ESOX , *FISH sex ratio , *FISH feeds , *OUTCROSSING (Biology) , *OVERFISHING - Abstract
Intraspecific genetic admixture occurs when previously separated populations within a species start interbreeding, and it can have either positive, negative, or neutral effects on reproductive performance. As there currently is no reliable predictor for the outcome of admixture, an increased knowledge about admixture effects in different species and populations is important to increase the understanding about what determines the response to admixture. We tested for effects of admixture on F1 offspring quality in three subpopulations of pike (Esox lucius). Gametes were collected in the field, and eggs from each female were experimentally fertilized with milt from a male from each population (one "pure" and two "admixed" treatments). Three offspring quality measures (hatching success, fry survival, and fry length) were determined and compared between (a) pure and admixed population combinations and (b) the sex‐specific treatments within each admixed population combination (based on the origin of the male and female, respectively). The results suggested that although there were no overall effects of admixture on offspring quality, the consequences for a given population combination could be sex‐specific and thus differ depending on which of the parents originated from one or the other population. All offspring quality traits were influenced by both maternal ID and paternal ID. Sex‐ and individual‐specific effects can have implications for dispersal behavior and gene flow between natural populations, and are important to consider in conservation efforts. We tested for effects of genetic admixture on offspring quality in three natural subpopulations of pike (Esox lucius) in an artificial fertilization experiment with a common garden setup. The results revealed that although there were no overall effects on offspring quality on the population level, the effects for a given combination of populations could differ depending on which of the parents originated from one or the other population. Such sex‐specific effects have implications for dispersal behavior and gene flow between natural populations, and are important to consider in conservation efforts. [ABSTRACT FROM AUTHOR]
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- 2018
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11. Season and species influence stable isotope ratios between lethally and non‐lethally sampled tissues in freshwater fish
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Brian Hayden, Karling N. Roberts, Mark S. Poesch, and Taylor Lund
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Carbon Isotopes ,Coregonus clupeaformis ,Perch ,Nitrogen Isotopes ,biology ,Isotope ,Stable isotope ratio ,Zoology ,Fresh Water ,Aquatic Science ,biology.organism_classification ,Perches ,Freshwater fish ,Animals ,Seasons ,computer ,Ecology, Evolution, Behavior and Systematics ,Esox ,Pike ,computer.programming_language ,Trophic level - Abstract
The field of stable isotope ecology is moving away from lethal sampling (internal organs and muscle) towards non-lethal sampling (fins, scales and epidermal mucus). Lethally and non-lethally sampled tissues often differ in their stable isotope ratios due to differences in metabolic turnover rate and isotopic routing. If not accounted for when using non-lethal tissues, these differences may result in inaccurate estimates of resource use and trophic position derived from stable isotopes. To address this, the authors tested whether tissue type, season and their interaction influence the carbon and nitrogen stable isotope ratios of fishes and whether estimates of species trophic position and resource use are affected by tissue type, season and their interaction. This study developed linear conversion relationships between two fin types and dorsal muscle, accounting for seasonal variation. The authors focused on three common temperate freshwater fishes: northern pike Esox lucius, yellow perch Perca flavescens and lake whitefish Coregonus clupeaformis. They found that fins were enriched in 13 C and depleted in 15 N compared to muscle in all three species, but the effect of season and the interaction between tissue type and season were species and isotope dependent. The estimates of littoral resource use based on fin isotope ratios were between 13% and 36% greater than those based on muscle across species. Season affected this difference for some species, suggesting the potential importance of using season-specific conversions when working with non-lethal tissues. Fin and muscle stable isotopes produced similar estimates of trophic position for northern pike and yellow perch, but fin-based estimates were 0.2-0.4 trophic positions higher than muscle-based estimates for lake whitefish. The effect of season was negligible for estimates of trophic position in all species. Strong correlations existed between fin and muscle δ13 C and δ15 N values for all three species; thus, linear conversion relationships were developed. The results of this study support the use of non-lethal sampling in stable isotope studies of fishes. The authors suggest that researchers use tissue conversion relationships and account for seasonal variation in these relationships when differences between non-lethal tissues and muscle, and seasonal effects on those differences, are large relative to the scale of isotope values under investigation and/or the trophic discrimination factors under use.
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- 2021
12. FISHERY CHARACTERISTICS OF PIKE ESOX LUCIUS (L.) OF TOPO-PYAOZERO RESERVOIR (WHITE SEA CATCHMENT AREA)
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Vyacheslav Anatolievich Shirokov, Nadezhda Stepanovna Cherepanova, and Andrey Pavlovich Georgiev
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Fishery ,White (horse) ,Geography ,biology ,Catchment area ,biology.organism_classification ,computer ,Esox ,Pike ,computer.programming_language - Abstract
The article presents the results of the work carried out within the framework of forecast topics and economic contractual topics aimed to assess the stock and production of pike in the Topo-Pyaozero (Kumskoe) Reservoir. There have been studied its main biological and structural-population indicators. Calculations of indicators of pike’s abundance and biomass at the present stage, necessary for the rational regulation of the fishery have been carried out. It was found that the fishing possibilities of the presented pike populations correspond to the production possibilities of its sexually mature part and the value obtained as a result of the biomass increase. Pike should be taken into the commercial operation from the age of 4+ years and older. The performed calculations of the stock size based on the materials of 2009–2020 recommend the volume of the pike total allowable catch at the present stage not less than 36 tons, or 21% of the value of the commercial stock (at the maximum rate of 23.4%). From the results of observations it follows that the abundance and stocks of pike in the Topo-Pyaozero Reservoir make it possible to provide large volumes of catch at the present time, and the total catch can be increased to the calculated values the volume of the allowable catch, provided that a rational fishery is maintained in water bodies. The intensity of fishing and an increase in pike catches in the reservoir should be considered as mandatory measures in terms of biological reclamation in reservoirs
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- 2021
13. Data‐poor stock assessment of fish stocks co‐exploited by commercial and recreational fisheries: Applications to pike Esox lucius in the western Baltic Sea
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Dieter Koemle, Helmut M. Winkler, Rob van Gemert, and Robert Arlinghaus
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Stock assessment ,Ecology ,biology ,Fishing ,coastal stocks ,stock status ,freshwater stocks ,570 Biologie ,Aquatic Science ,Fish stock ,biology.organism_classification ,catch‐only models ,mixed‐use fisheries ,Fishery ,Geography ,Recreational fishing ,ddc:570 ,ensemble models ,Recreation ,computer ,Esox ,Stock (geology) ,Pike ,computer.programming_language - Abstract
Information on catch and effort of recreational angling in mixed‐use fisheries (co‐exploited by commercial and recreational fishers) is often scarce, preventing the application of data‐rich stock assessments typically performed for industrialised commercial fisheries. This study shows how data‐poor stock assessment methods developed for marine fisheries, particularly a model class labelled as “catch‐only” models (COMs), offer a possible solution. As a case study, COMs are used to assess a northern pike Esox lucius L. stock around the German Baltic island of Rügen. Multiple COMs were fitted to a time series of total pike removals, and their outputs were used as explanatory variables in ensemble models. The stock was found to be fully exploited and currently declining. This study highlights the potential for using COMs to determine status of previously unassessed coastal and freshwater stocks facing recreational fishing pressure and demonstrates how incorporating recreational removals is crucial for achieving reliable insights into the status of mixed‐use stocks. European Maritime Fisheries Fund (EMFF) of the EU and the State of Mecklenburg‐Vorpommern (Germany)
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- 2021
14. Predator biomass and vegetation influence the coastal distribution of threespine stickleback morphotypes
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Ulf Bergström, Joakim P. Hansen, Sorsha A. Passmore, Fiona Colgan Carey, Martine E. Maan, Casey Yanos, Eeke P. Haanstra, Johan S. Eklöf, Britas Klemens Eriksson, Michael C. Fontaine, Groningen Institute for Evolutionary Life Sciences [Groningen] (GELIFES), University of Groningen [Groningen], Diversity, ecology, evolution & Adaptation of arthropod vectors (MIVEGEC-DEEVA), Evolution des Systèmes Vectoriels (ESV), Maladies infectieuses et vecteurs : écologie, génétique, évolution et contrôle (MIVEGEC), Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD [France-Sud])-Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD [France-Sud])-Maladies infectieuses et vecteurs : écologie, génétique, évolution et contrôle (MIVEGEC), Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD [France-Sud])-Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD [France-Sud]), Eriksson group, Fontaine lab, and Maan group
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0106 biological sciences ,ecosystem perturbation ,Population ,habitat specialization ,Gasterosteus ,010603 evolutionary biology ,01 natural sciences ,Predatory fish ,14. Life underwater ,education ,QH540-549.5 ,Ecology, Evolution, Behavior and Systematics ,Esox ,Original Research ,Nature and Landscape Conservation ,Perch ,education.field_of_study ,Ecology ,biology ,stickleback ,010604 marine biology & hydrobiology ,[SDV.BID.EVO]Life Sciences [q-bio]/Biodiversity/Populations and Evolution [q-bio.PE] ,Niche differentiation ,Niche segregation ,Stickleback ,biology.organism_classification ,intraspecific variation ,13. Climate action ,[SDE]Environmental Sciences ,[SDE.BE]Environmental Sciences/Biodiversity and Ecology ,ecotypic divergence - Abstract
Intraspecific niche differentiation can contribute to population persistence in changing environments. Following declines in large predatory fish, eutrophication, and climate change, there has been a major increase in the abundance of threespine stickleback (Gasterosteus aculeatus) in the Baltic Sea. Two morphotype groups with different levels of body armor—completely plated and incompletely plated—are common in coastal Baltic Sea habitats. The morphotypes are similar in shape, size, and other morphological characteristics and live as one apparently intermixed population. Variation in resource use between the groups could indicate a degree of niche segregation that could aid population persistence in the face of further environmental change. To assess whether morphotypes exhibit niche segregation associated with resource and/or habitat exploitation and predator avoidance, we conducted a field survey of stickleback morphotypes, and biotic and abiotic ecosystem structure, in two habitat types within shallow coastal bays in the Baltic Sea: deeper central waters and shallow near‐shore waters. In the deeper waters, the proportion of completely plated stickleback was greater in habitats with greater biomass of two piscivorous fish: perch (Perca fluviatilis) and pike (Esox lucius). In the shallow waters, the proportion of completely plated stickleback was greater in habitats with greater coverage of habitat‐forming vegetation. Our results suggest niche segregation between morphotypes, which may contribute to the continued success of stickleback in coastal Baltic Sea habitats., Following declines in large predatory fish, eutrophication, and climate change, there has been a major increase in the abundance of two morphotype groups of threespine stickleback (Gasterosteus aculeatus) in the Baltic Sea. In deeper coastal waters, the proportion of completely plated stickleback was greater in habitats with greater biomass of two piscivorous fish: perch (Perca fluviatilis) and pike (Esox lucius) and in shallow coastal waters. The proportion of completely plated stickleback was greater in habitats with greater percent coverage of habitat‐forming vegetation. Our results suggest niche segregation between morphotypes, which may contribute to the continued success of stickleback in coastal Baltic Sea habitats.
- Published
- 2021
15. SPECIES COMPOSITION AND RELATIVE POPULATION SIZE OF FISHES IN THE OSTER RIVER (THE DESNA RIVER BASIN): 50 YEARS ANALYSIS
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S. V. Kokodii, S. V. Mezhzherin, А. О. Tsyba, and D. S. Lutsenko
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education.field_of_study ,Leuciscus ,Extinction ,Neogobius ,biology ,Habitat ,Ecology ,Chondrostoma ,Population ,Rutilus ,education ,biology.organism_classification ,Esox - Abstract
Inroduction. Changes in the species composition and population size of freshwater fihes are determined by deformations of the habitat in Ukraine and are characterized by a pronounced negative dynamics. Deformation of ichthyofauna is caused by extinction of a number of aboriginal fihes and emergence of alien species.Aim. To establish the current species composition and relative population size of fih species in the Oster River and the dynamics of these characteristics over a 50-yearlong period in the context of negative transformations of the ichthyofauna of the rivers of Ukraine.Results. Comparative study of the species composition and relative population size of fih species in the fih catches by small-river fihing gear in the Oster river was conducted during the period since 1971-72 till 2019. During this time considerable changes in species composition took place. The following species disappeared from the catches: Leuciscus leuciscus, Leuciscus idus, Chondrostoma nasus, Carassius carassius, Blicca bojerkna and Neogobius flviatilis, they were replaced by three invasion species (Percottus glenni, Pseudorasbora parva, Proterorhinus marmoratus). The changes in the dominant species took place, thus, in the Oster ichthyocene the species with the short life cycle started to prevail, the share of invasion species increased from 1.4 to 37%, and the share of initial marine fih among them is very low. The comparison with the river systems of the Stugna and the Lower Dnipro represents the fact that the mentioned negative tendencies are common for the whole Dnipro system, however the situation in the Lower Dnipro must be considered less critical than in the Oster and the Stugna rivers. The fact that the catches of industrial fih decreased more than 10 times in the Desna river during this period of time gives the reason to consider that the dramatic reduction of the absolute number of their populations occurred in the Oster river as well. That is why even relatively safe species (Abramis brama, Rutilus ritilus, Scardinius erythrophthalmus, Esox lucius, Perca flviatilis, Alburnus alburnus, Squalius cephalus) are in critical situation in this transformed river system.Сonclusions. In the ichthyocene of the Oster River over a 50-year period there have been signifiant changes in species composition, relative and absolute population numbers associated with the extinction and reduction of population sizes of rheophilic species and fih that are adapted to life in the flodplain. The modern Oster River is dominated by invasive and short-cycle species. The obtained tendencies in the dynamics of the ichthyofauna of the Oster River are similar to the nature of changes in other river systems of Ukraine, although they occur at a faster pace, which is characteristic of the smallest plain rivers.
- Published
- 2021
16. Effect of feed restriction on fatty acid profile, body composition and selected blood parameters of intensive reared pike (Esox lucius)
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Balázs Kucska, Chris Blake, András Szabó, Csaba Hancz, and Dániel Varga
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chemistry.chemical_classification ,biology ,Fatty acid ,biology.organism_classification ,chemistry ,General Earth and Planetary Sciences ,Composition (visual arts) ,Food science ,Blood parameters ,computer ,Esox ,General Environmental Science ,Pike ,computer.programming_language - Abstract
This study investigated the effects of a six-week starvation period on the fatty acid profile, body composition and blood parameters of intensively reared pike (Esox lucius). 150 pike were stocked in an experimental recirculating aquaculture system (RAS) and feed was completely withdrawn. Body composition, fatty acid composition and blood parameters (serum protein, albumin, triacylglycerol, cholesterol concentration and Lactate dehidrigenase and alkaline phosphatase activity) were measured and somatic indices were calculated. A significant decline in bodyweight, crude fat content and somatic indices was accompanied by a significant decrease of blood triacylglycerol content. The relative proportion of saturated fatty acids in the fillet decreased, while polyunsaturated fatty acids increased. There was also a significant increase in the average chain length and unsaturation index of fatty acids found in the fillet flesh.
- Published
- 2021
17. Lake Maslozero Ecosystem and the Results of the Release of the Smelt Osmerus eperlanus into the Lake
- Author
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N. V. Ilmast, Denis Savosin, A. N. Sharov, O. P. Sterligova, E. S. Savosin, and Ya. A. Kuchko
- Subjects
Perch ,biology ,food.dish ,biology.organism_classification ,Fishery ,Predatory fish ,food ,Coregonus lavaretus ,Environmental science ,Osmerus eperlanus ,Rutilus ,Smelt ,computer ,Ecology, Evolution, Behavior and Systematics ,Esox ,Pike ,computer.programming_language - Abstract
The results of the study of the Lake Maslozero ecosystem (the White Sea basin) are reported. The lake is small, deep, and poorly lotic. Its hydrochemical and hydrobiological parameters were studied. The quantitative and structural characteristics of the state of zooplankton and macrozoobenthos in the lake are presented for the first time. The lake is an oligo-mesotrophic water body, as indicated by the nutrient content scale. The lake is inhabited by 14 fish species of 11 families. The perch Perca fluviatilis, the whitefish Coregonus lavaretus, the pike Esox lucius, the roach Rutilus rutilus, and the introduced smelt Osmerus eperlanus are the most abundant. The work on the introduction of smelt into Lake Maslozero is evaluated. The smelt in the lake has naturalized, is successfully reproducing, and has become abundant. Its growth rate is identical to that of the smelt from its parental water body, Lake Ladoga. The food ration of predatory fish (pike, burbot, perch, and char) is dominated by smelt as the most abundant and accessible food item available all year round. The lake is used by the local population for economic purposes, recreation, amateur fishing, and fish culture.
- Published
- 2021
18. Oil sands tailings pond sediment toxicity to early life stages of northern pike (Esox lucius).
- Author
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Raine, J.C., Turcotte, D., Romanowski, L., and Parrott, J.L.
- Subjects
- *
OIL sands , *POND sediments , *ESOX , *BITUMEN , *MINES & mineral resources - Abstract
The Athabasca River in Alberta flows through natural sources of eroding oil sands bitumen and oil sands mining operations that may result in low level contamination of surface waters. Northern pike ( Esox lucius ) are apex predators and important food and game fish species native to the Athabasca River system. This species has the potential to be exposed to both natural and anthropogenic sources of contamination from oil sands related materials throughout its life cycle. Pike are difficult to rear in the laboratory and little information exists on the toxicity of oil sands related materials to this key indigenous fish species. In this study, the potential effects of two sediment samples collected from different areas of one tailings pond in the Athabasca oil sands area are assessed in a daily renewal bioassay on early life stages of northern pike. Gametes were collected from spawning wild pike captured from a reference site outside of the oil sands area. Fertilized eggs were exposed to control water or increasing concentrations of tailings pond sediments for 21 days, coinciding with initiation of exogenous feeding and completion of yolk absorption. Developing fish were examined for survival and changes in body weight, length, and development. Embryos exhibited increased developmental abnormalities and decreased growth and survival with increasing sediment concentration. Both sediment samples had similar levels of naphthenic acids and similar types of PAHs, with alkylated PAHs dominating. However, concentrations of total and alkylated PAHs differed between sediment samples and were related to increasing developmental abnormalities and decreased growth and survival. This is consistent with developmental changes observed with exposure to PAHs in other fish species. These results provide information on the effects of tailings pond sediments comprising mixtures of PAHs and alkylated PAHs on the development and survival of a key species in the northern aquatic ecosystem. [ABSTRACT FROM AUTHOR]
- Published
- 2018
- Full Text
- View/download PDF
19. Relationships between individual movement, trophic position and growth of juvenile pike ( Esox lucius).
- Author
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Nyqvist, Marina J., Cucherousset, Julien, Gozlan, Rodolphe E., and Britton, J. Robert
- Subjects
- *
ESOX , *TELEMETRY , *FORAGING behavior , *FISH populations , *SPATIAL behavior , *TRANSPONDERS - Abstract
Variation in movement between individuals can have important ecological effects on populations and ecosystems, yet the factors driving differences in movement and their consequences remain poorly understood. Here, individual variability in the movements of juvenile (age 0 + and 1 + year) pike Esox lucius was assessed using passive integrated transponder ( PIT) telemetry in off-channel nursery areas over a 26- month period. Differences in the movement patterns of individuals were tested against their body sizes, ages, growth rates and trophic positions using data collected through a combination of catch-and-release sampling and stable isotope analyses. Results revealed that variation in movement between individuals was affected by age, with 1 + individuals moving more than individuals of age 0 + , but not length. Individuals whose TP was low on their initial capture event moved significantly less than those with a higher initial TP. Individuals that moved more grew faster and achieved a higher final TP. These results suggest that higher activity (i.e., increased movement) increases resource acquisition that enhances growth rates, which could ultimately maximise individual performances. [ABSTRACT FROM AUTHOR]
- Published
- 2018
- Full Text
- View/download PDF
20. Mercury concentrations in commercial fish species from Lake Winnipeg, 1971–2019
- Author
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Wolfgang Jansen
- Subjects
0106 biological sciences ,Coregonus clupeaformis ,Ecology ,biology ,010604 marine biology & hydrobiology ,chemistry.chemical_element ,010501 environmental sciences ,Aquatic Science ,biology.organism_classification ,Fish measurement ,01 natural sciences ,Mercury (element) ,Fishery ,chemistry ,Environmental science ,Bay ,computer ,Ecology, Evolution, Behavior and Systematics ,Esox ,0105 earth and related environmental sciences ,Invertebrate ,Pike ,computer.programming_language ,Trophic level - Abstract
Concentrations of total mercury (THg) in the axial musculature of northern pike (Esox lucius), walleye (Sander vitreus), lake whitefish (Coregonus clupeaformis), and sauger (Sander canadensis) were analyzed from several regions of Lake Winnipeg and three main inflows, focusing on Mossy Bay in the North Basin of the lake. Length-standardized means (standard means) indicated THg concentrations in pike of 550 mm fork length (0.44 ppm) and walleye measuring 400 mm (0.38 ppm) from Mossy Bay were highest in 1971 and declined to 0.13 and 0.22 ppm, respectively, by 1974. Standard means of both these species have been similar since 2010 (walleye; approximately 0.11 ppm) and 2013 (pike; approximately 0.17 ppm), except for a significant increase to 0.15 ppm in walleye in 2019, potentially related to concurrent changes in trophic interactions with invasive fish and invertebrate species. Standard means of 300 mm long sauger (0.23–0.29 ppm) did not decline significantly between 1971 and 1974, and those of 350 mm long whitefish ranged from 0.006 to 0.028 ppm from 1983 to 2016 with no clear temporal trend. In concert with data from other areas of Lake Winnipeg and the three inflows for 2000–2019, these results indicate higher contemporary concentrations in the South Basin of the lake. This latitudinal gradient in fish THg is assumed to be a result of continuous mercury inputs from the Red and the Winnipeg River, whereas a former point source of industrial mercury in the Saskatchewan River is no longer relevant. According to human consumption limits based on tolerable daily intake calculations and current THg concentrations of fish from Mossy Bay, substantial quantities of whitefish, pike, and walleye fish can be safely eaten.
- Published
- 2021
21. A nitrogen factor for European pike-perch (Sander lucioperca), northern pike (Esox lucius), and sheatfish (Silurus glanis) fillets
- Author
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Lenka Schebestova, Anna Koubová, Alena Honzlova, Alzbeta Stara, Josef Velisek, Helena Curdova, Zdenka Svobodova, and Josef Priborsky
- Subjects
fish ,Perch ,biology ,Zoology ,SH1-691 ,04 agricultural and veterinary sciences ,Aquatic Science ,biology.organism_classification ,Sander ,040401 food science ,nitrogen factor ,Adulteration ,0404 agricultural biotechnology ,fish-food fraud ,040102 fisheries ,Aquaculture. Fisheries. Angling ,fish products ,0401 agriculture, forestry, and fisheries ,Silurus ,computer ,Esox ,Pike ,computer.programming_language - Abstract
Measures for consumer protection against food adulteration and misleading labeling are integrated into EU legislation, including methods for detection of misleading practices. Verification of meat content is available for marine products but not for freshwater fish because of the lack of standard nitrogen factors. The aim of this study was to establish nitrogen factors for European pike-perch Sander lucioperca (Linnaeus, 1758), northern pike Esox lucius Linnaeus, 1758, and sheatfish Silurus glanis Linnaeus, 1758. The study involved analysis of 808 fillet samples obtained in spring (March–April) and autumn (October–November) harvest seasons, 2018–2019, from seven Czech Republic fish rearing facilities. Samples with and without skin were analyzed for nitrogen content, dry matter, protein, ash, and fat according to established ISO methods. The recommended nitrogen factor for European pike-perch with the skin is 3.28 ± 0.09 and without the skin is 3.21 ± 0.09; for northern pike with the skin is 3.18 ± 0.09 and without skin is 3.15 ± 0.09; and for sheatfish with skin is 2.73 ± 0.13 and without skin is 2.75 ± 0.12. The established nitrogen factors will enable analysis of meat content to ensure that consumers are purchasing correctly described and labeled fish products.
- Published
- 2021
22. The Average Weight of Fish Caught by Anglers at the Croatian Section of the Sava River Catchment
- Author
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Tomislav Treer
- Subjects
0106 biological sciences ,silurus glanis ,cyprinus carpio ,Fishing ,SH1-691 ,Management, Monitoring, Policy and Law ,Aquatic Science ,Body weight ,010603 evolutionary biology ,01 natural sciences ,esox lucius ,Aquaculture. Fisheries. Angling ,sander lucioperca ,freshwater ,Ecology, Evolution, Behavior and Systematics ,Esox ,Croatian ,Ecology ,biology ,010604 marine biology & hydrobiology ,biology.organism_classification ,language.human_language ,Fishery ,Geography ,language ,%22">Fish ,Fisheries management ,recreational fishermen ,Silurus ,River catchment - Abstract
The aim of this research is to compare the average individual weight of the four most important fish species in fisheries (Cyprinus carpio, Silurus glanis, Esox lucius and Sander lucioperca), caught by angling in different parts of the Sava River catchment in Croatia. Significant differences were expressed between the counties along the Sava River catchment, with the smallest specimens (p˂0.05) caught in Vukovar-Sirmium county. Artisanal fishery is mostly developed in that part of the Sava River, along with angling in both countries – Croatia and Bosnia and Herzegovina. Furthermore, the inflow of the River Bosna passes through urban and industrial cities of Bosnia and Herzegovina. It can be concluded that implementing recreational fishing surveys with the specific aim of obtaining data on average individual weight is useful for fishery management.
- Published
- 2021
23. Efficiency of Northern pike ( Esox lucius ) stocking in metropolitan France at large spatial and temporal scales
- Author
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Camille Musseau, Julien Cucherousset, Géraldine Loot, Paul Millet, Simon Blanchet, Frédéric Santoul, and Nicolas Guillerault
- Subjects
Ecology ,biology ,Aquatic Science ,biology.organism_classification ,Metropolitan France ,Fishery ,Predatory fish ,Stocking ,Geography ,Recreational fishing ,Temporal scales ,computer ,Size dependence ,Esox ,Pike ,computer.programming_language - Published
- 2021
24. Genomic inbreeding and population structure of northern pike (Esox lucius) in Xinjiang, China
- Author
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Bo Ma, Dan Song, Tangbin Huo, Guo Hu, Peixian Luan, and Xiaofeng Zhang
- Subjects
0106 biological sciences ,Population ,Drainage basin ,Zoology ,010603 evolutionary biology ,01 natural sciences ,identity by descent ,Gene flow ,03 medical and health sciences ,Effective population size ,Inbreeding ,education ,Ecology, Evolution, Behavior and Systematics ,Esox ,QH540-549.5 ,030304 developmental biology ,Nature and Landscape Conservation ,Pike ,computer.programming_language ,0303 health sciences ,education.field_of_study ,geography ,geography.geographical_feature_category ,biology ,Ecology ,Esox Lucius ,Northern Hemisphere ,biology.organism_classification ,coancestry coefficient ,gene flow ,computer ,effective population size - Abstract
Northern pike (Esox lucius) was widely distributed in the high latitudes of the northern hemisphere. In China, northern pike was originally distributed only in the upper reaches of the Irtysh River in Xinjiang and has appeared in many water bodies outside the Irtysh River Basin in Northern Xinjiang. A total of four populations were collected from north to south in Xinjiang, including Irtysh River (RIR), Ulungu Lake (LUL), a small lake nearby Ulungu River (LJD), and Bosten Lake (LBO). We estimated population genomic parameters, performed gene flow analysis, and estimated the effective population size of each population. The proportion of individuals with high inbreeding coefficient (F ≥ 0.0625) accounted for 36.4% (44/121) of all sequenced individuals, approximately 4.5% (1/22) in LUL, 25.9% (7/27) in LBO, 42.9% (18/42) in RIR, and 60% (18/30) in LJD. RIR had the highest mean of genomic relatedness (coancestry coefficient = 0.025 ± 0.040, IBD = 0.036 ± 0.078). Gene flow results showed that the population spreading was from RIR into two branches, one was LBO, and the other continued to split into LUL and LJD, and migration signal from LBO to LUL was detected. Our results suggested that the extinction risk of northern pike was very low in Xinjiang of China, and the controlled capture fishery of northern pike could be developed reasonably.
- Published
- 2021
25. Do Carbonated Beverages Reduce Bleeding from Gill Injuries in Angled Northern Pike?
- Author
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Daniel M. Glassman, Michael J. Lawrence, Alexandria Trahan, Auston D. Chhor, Connor H. Reid, Andy J. Danylchuk, Steven J. Cooke, Jacob W. Brownscombe, and Alice E. I. Abrams
- Subjects
0106 biological sciences ,Gill ,Ecology ,biology ,business.industry ,010604 marine biology & hydrobiology ,Fishing ,Media coverage ,Context (language use) ,Management, Monitoring, Policy and Law ,Aquatic Science ,biology.organism_classification ,010603 evolutionary biology ,01 natural sciences ,Coca cola ,Toxicology ,Blood loss ,Medicine ,business ,computer ,Ecology, Evolution, Behavior and Systematics ,Esox ,Pike ,computer.programming_language - Abstract
The premise of catch-and-release angling is that most fish survive fisheries interactions. Therefore, it is common for anglers, management agencies, and other organizations to share information on handling practices and other strategies that are believed to improve fish welfare and survival. Recent media coverage has sensationalized the use of carbonated beverages to treat bleeding fish, an intervention that is purported to stop bleeding but has yet to be validated scientifically. We captured Northern Pike (Esox lucius) via hook and line, experimentally injured their gills in a standardized manner, and treated them with either Mountain Dew, Coca Cola, or carbonated lake water and observed the duration and intensity of bleeding, as well as overall blood loss (using gill colour as a proxy) while the fish was held in a lake water bath. As a control, we had a group of experimentally injured fish that did not have liquid poured over their gills before the observation period. All treatments and the control were conducted at two different water temperatures (11-18 °C and 24-27 °C) to determine if the effects of pouring carbonated beverages over injured gills is temperature dependent. When compared to the control, we found that the duration and intensity of bleeding increased regardless of the type of carbonated beverages used in this study, and there was no effect of water temperature. Use of chilled versus ambient temperature beverages similarly had no influence on outcomes. As such, there is no scientific evidence to support the use of carbonated beverages for reducing or stopping blood loss for fish that have had their gills injured during recreational angling based on the context studied here. This study reinforced the need to scientifically test angler anecdotes and theories when it comes to best practices for catch-and-release fishing.
- Published
- 2021
26. Level of natremia as an index of the condition of the organism of animals under stress
- Author
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R. A. Zaprudnova
- Subjects
medicine.medical_specialty ,biology ,Chemistry ,Sodium ,chemistry.chemical_element ,General Medicine ,030204 cardiovascular system & hematology ,medicine.disease ,biology.organism_classification ,03 medical and health sciences ,0302 clinical medicine ,Endocrinology ,Internal medicine ,Blood plasma ,medicine ,Freshwater fish ,030212 general & internal medicine ,Hypernatremia ,Rutilus ,Hyponatremia ,Organism ,Esox - Abstract
In the diagnosis of stressful conditions in humans and other animals, ionic indicators remain practically unused. In this work, we studied the changes in the concentrations of sodium ions in the blood plasma of freshwater fish under stress caused by stressors of different quality and quantity. Most of the experiments were carried out on adult bream (Abramis brama L) from the Rybinsk Reservoir. Separate experiments were duplicated on adult individuals of roach (Rutilus rutilus L.), pike (Esox lucius L.), and blue bream (Abramis ballerus L.). The concentration of cations in the blood plasma was determined using a Flapho-4 flame photometer. Under the action of mild and short-term stressors of different qualities, the sodium concentration in the internal environment altered toward an increase in concentration gradients on the cell membrane (eustress or physiological stress). Hypernatremia was approximately 10%. Under the action of strong and/or prolonged stressors of different strength, the sodium concentration in the internal environment changed toward a decrease in concentration gradients on the cell membrane (distress or pathological stress). Hyponatremia was 50% in the conditions of acute lethal stress, 20% in subacute lethal stress, 10% or more in chronic lethal stress. During strong acute reversible stress, hyponatremia could reach 30%. Analysis of the material on mammals allowed us to conclude that the adaptation mechanisms in fish and higher vertebrates are similar. In this work, for the first time, the state of the system of electrolyte balance of animals under stress was analyzed from the standpoint of the leading role of ionic concentration gradients on the cell membrane (mainly sodium) in the energetics (level of disequilibrium) of the organism. We propose a concept that in normal and extreme conditions fish use two different defense reactions (or adaptation strategies): active and passive, consisting, respectively, in increasing or decreasing the level of disequilibrium (energy) in the organism. The hyponatremia recorded by numerous authors, which accompanies diseases in humans, is evidently a nonspecific reaction of the organism and serves as an indicator of reduced energy of the organism. It is suggested that the sodium level in the internal environment of the organism be used for diagnosing the stress state of animals.
- Published
- 2021
27. Henneguya michiganensis n. sp. (Cnidaria: Myxosporea) from the gills of muskellunge Esox masquinongy Mitchill(Esociformes: Esocidae)
- Author
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Thomas P. Loch, Thomas G. Rosser, Mohamed Faisal, Wes A. Baumgartner, and Matt J. Griffin
- Subjects
Gills ,0106 biological sciences ,Gill ,0303 health sciences ,biology ,010607 zoology ,Zoology ,Esociformes ,biology.organism_classification ,01 natural sciences ,030308 mycology & parasitology ,Spore ,Myxosporea ,03 medical and health sciences ,Species Specificity ,Esox masquinongy ,Animal ecology ,Esocidae ,RNA, Ribosomal, 18S ,Animals ,Parasitology ,Polar filament ,Great Lakes Region ,Myxozoa ,Esox - Abstract
Henneguya Thélohan, 1892 is the second most species rich genus of myxozoans, with reports from freshwater and marine fish worldwide. In the Great Lakes region of North America, muskellunge Esox masquinongy is an important game fish species that serves as an apex predator in the ecosystems of many inland lakes. The myxozoan fauna of esocid fish, especially muskellunge, remains largely understudied. During fish health assessments, muskellunge were examined for parasitic infections and myxozoan pseudocysts were observed on gill clip wet mounts. When ruptured under pressure, the intralamellar pseudocysts released thousands of myxospores consistent with those of the genus Henneguya. The myxospores were 67.3-96.6 (79.1 ± 5.9) µm in total length. The spore body was 18.6-22.6 (20.9 ± 1.0) µm × 5.4-6.9 (6.3 ± 0.4) µm in valvular view and 3.5-4.0 (3.8 ± 0.3) µm wide in sutural view. The two pyriform polar capsules positioned at the anterior of the spore body were 6.4-7.7 (7.0 ± 0.4) µm × 1.8-2.1 (2.0 ± 0.1) µm and each contained a tightly coiled polar filament with 9-10 turns. Two tapering caudal processes extended from the posterior of the spore body and were 47.3-75.6 (58.3 ± 5.8) µm in length. Histologically, large intralamellar polysporic plasmodia were surrounded by plump pillar cells and a distinct layer of plasma. Mild inflammation was present peripherally, with small numbers of necrotic germinative cells and intraplasmodial phagocytes internally. Ribosomal 18S rRNA gene sequence data were obtained from three gill pseudocysts. The three ~2000-bp sequences were identical, but shared no significant similarity with any publicly available sequence data. Phylogenetic analyses demonstrated sequence data from this Henneguya fell within a well-supported clade of Henneguya spp. reported from northern pike Esox lucius in Europe. Based on the distinct morphological, histological and molecular data, this species is designated as Henneguya michiganensis n. sp. from muskellunge in Michigan, USA.
- Published
- 2021
28. A Short Review on the Biological Characteristics of the Species Esox Lucius, Linnaeus, 1758 in Caspian Sea Basin (Iran)
- Author
-
Mohammad Forouhar Vajargah and Navid Ebrahimzadeh Kouchesfahani
- Subjects
021110 strategic, defence & security studies ,Ecology ,biology ,caspian sea basin ,0211 other engineering and technologies ,Endangered species ,northern pike ,02 engineering and technology ,010501 environmental sciences ,biology.organism_classification ,01 natural sciences ,Predation ,Fishery ,Predatory fish ,Geography ,Genus ,Freshwater fish ,computer ,QH540-549.5 ,Esox ,0105 earth and related environmental sciences ,Pike ,computer.programming_language ,Invertebrate - Abstract
The Esox genus belongs to the family Esocidae. It is a freshwater fish that can be found in different parts of Europe, Asia, and North America. The Northern Pike, is a carnivorous fish, member of the only remaining genus of the Esocidae. This fish prefers to lead a solitary life due to the disadvantages of the presence of individuals of the same species which compete for food resources and territory. Waiting for a suitable situation to catch prey is a favoured hunting method, which means this specific species is a lie-in-wait predator. The elongated body and the broad snout are the most striking features used for the identification of this species. This lie-in-wait carnivorous predator mostly feeds on invertebrates and fishes. The species spawns annually. The special living conditions of this species and their endangered environment have made it necessary to avoid any acts that can affect their life quality.
- Published
- 2021
29. Widespread Seropositivity to Viral Hemorrhagic Septicemia Virus (VHSV) in Four Species of Inland Sport Fishes in Wisconsin
- Author
-
Megan Finley, Tony L. Goldberg, Bridget B. Baker, David Giehtbrock, Kathy L. Toohey-Kurth, and Whitney A. Thiel
- Subjects
Viral hemorrhagic septicemia virus VHSV ,Trout ,040301 veterinary sciences ,Zoology ,Aquatic Science ,Percent Inhibition ,Serology ,Novirhabdovirus ,0403 veterinary science ,Fish Diseases ,Brown trout ,Wisconsin ,Seroepidemiologic Studies ,Hemorrhagic Septicemia, Viral ,Animals ,Salmo ,Esox ,Pike ,computer.programming_language ,biology ,Outbreak ,04 agricultural and veterinary sciences ,biology.organism_classification ,Perciformes ,Perches ,Esocidae ,040102 fisheries ,0401 agriculture, forestry, and fisheries ,computer - Abstract
Serological assays were conducted for anti-viral hemorrhagic septicemia virus (VHSV) antibodies in four species of fish in Wisconsin (Bluegill Lepomis macrochirus, Brown Trout Salmo trutta, Northern Pike Esox lucius, and Walleye Sander vitreus) to examine spatial and temporal distributions of exposure. Sera were tested for non-neutralizing anti-nucleocapsid antibodies to VHSV by blocking enzyme-linked immunosorbent assay (ELISA). Results (percent inhibition [%I]) were analyzed for differences among species, across geographic distance, and among water management units. Positive fish occurred in 37 of 46 inland water bodies tested, including in water bodies far from reported outbreak events. Using highly conservative species-specific thresholds (mean %I of presumptive uninfected fish + 2 SDs), 4.3% of Bluegill, 13.4% of Brown Trout, 19.3% of Northern Pike, and 18.3% of Walleye tested positive for VHSV antibodies by ELISA. Spatial patterns of seropositivity and changes in %I between sampling years were also analyzed. These analyses explore how serology might be used to understand VHSV distribution and dynamics and ultimately to inform fisheries management.
- Published
- 2021
30. Trophic flexibility of Eurasian otter (Lutra lutra) in Anzali Wetland, Iran, assessed by fecal and stable isotope analysis
- Author
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Alireza Mirzajani, Saeid Naderi, Morteza Salahi, Ehsan Hadipour, Jamileh Javidpour, and Ahmad Ganeh
- Subjects
0106 biological sciences ,Prussian carp ,biology ,010604 marine biology & hydrobiology ,Zoology ,Species diversity ,15. Life on land ,Aquatic Science ,biology.organism_classification ,010603 evolutionary biology ,01 natural sciences ,Otter ,Predation ,biology.animal ,Carassius ,14. Life underwater ,Lutra ,Ecology, Evolution, Behavior and Systematics ,Esox ,Trophic level - Abstract
Information on the feeding habits of species is essential to develop appropriate conservation actions. This study aimed to assess spatial and temporal variation in the diet of the Eurasian otter, Lutra lutra in the Anzali Wetland, through fecal and stable isotope analysis. Seven main prey items were observed in the analysis of 300 fresh spraints. The highest feeding index was observed for fish, followed by snakes. Among the fish species consumed, the index of preponderance of Prussian carp (Carassius gibelio) was the highest followed by pike (Esox lucius) and white bream (Blicca bjoerkna). Results of Shannon diversity index suggest spatial variation of species diversity within and between feeding items (p < 0.05); snakes, frogs, and oriental river prawn (Macrobrachium nipponense) showed a seasonal variation. The otter’s trophic level (TL) (3.79) was higher than the TLs of other Anzali Wetland predators, such as pike. Bayesian mixing model showed source proportion contributions of fish 49.5%, reptiles 16.7%, insects 14.8%, crustacean 10.5%, amphibians 4.3%, birds 4.1%, and mollusks 0.1%. When considering only fish species in the Bayesian mixing model, Prussian carp was the main fish prey in the otters’ diet accounting for 47%. Based on the results of this study, the Eurasian otter plays an important role in the ecology of the Anzali Wetland ecosystem even though it preys on exotic species, such as the Prussian carp and the oriental river prawn.
- Published
- 2021
31. Community-based monitoring in the Ponoy River, Kola Peninsula (Russia): reflections on Atlantic salmon, pink salmon, Northern pike and weather/climate change
- Author
-
Jevgeni Kirillov, Johanna Roto, Denis Barudkin, Anna Koleshnikova, Tero Mustonen, Kaisu Mustonen, Alexander Paul, Brie Van Dam, Marie Kvarnström, Irina Kurzeneva, and Håkan Tunon
- Subjects
0106 biological sciences ,biology ,010604 marine biology & hydrobiology ,Climate change ,Introduced species ,biology.organism_classification ,010603 evolutionary biology ,01 natural sciences ,Fishery ,Oncorhynchus ,Catchment area ,Salmo ,General Agricultural and Biological Sciences ,computer ,Esox ,Wilderness area ,Pike ,computer.programming_language - Abstract
This paper documents changes in three villages of the Ponoy River region, Murmansk, Russia between 2006 and 2020. Two keystone species—the Atlantic salmon (Salmo salar) and northern pike (Esox lucius) as well as an introduced species, the pink salmon (Oncorhynchus gorbuscha), were studied to determine changes to fish and fisheries. Oral histories, community-based observations and literature data are used to establish key messages on river health from the 1800s to 2020, including temperature data from 1864 to present. Climate change becomes increasingly evident and impacts the Ponoy River system from 1980s onwards with system-relevant changes becoming more pronounced in late 2010s. This coincides with proliferation of pink salmon from 2006 onwards. The species was introduced from the Russian Far East in the 1930s. Very few long-term community-based observation processes have taken place in the Russian North and this paper corrects this to certain extent. Ponoy River and region are important as the last major roadless wilderness area of the European North. Societal and climate changes are rapidly impacting the river and its catchment area as well as the available biological resources and consequently the local culture. This study shows the value of local communities to determine base lines and highlight ongoing changes when establishing climate change impacts and impacts of an alien species.
- Published
- 2021
32. Predator kairomones elicit bold, exploratory behaviours in juvenile bluegill, Lepomis macrochirus
- Author
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Chris K. Elvidge, V.D. Ramsaran, Michael J. Lawrence, S.M. Bucciol, T. Puniani, and B.L. Jackson
- Subjects
0106 biological sciences ,biology ,Boldness ,media_common.quotation_subject ,05 social sciences ,Zoology ,Cognition ,biology.organism_classification ,010603 evolutionary biology ,01 natural sciences ,Kairomone ,Juvenile ,0501 psychology and cognitive sciences ,Animal Science and Zoology ,050102 behavioral science & comparative psychology ,computer ,Predator ,Lepomis macrochirus ,Ecology, Evolution, Behavior and Systematics ,Esox ,Pike ,computer.programming_language ,media_common - Abstract
Behavioural responses of animals are often placed conceptually along some axis characterized by the extremes, e.g. bold versus shy or timid. Ecological and evolutionary pressures can be associated with increased frequencies of different behavioural patterns that are also subject to intrinsic factors such as differing metabolic requirements or cognitive abilities. We exposed individual wild-caught juvenile bluegill, Lepomis macrochirus, to kairomones from predatory northern pike, Esox lucius, or to lake water controls during a Z-maze arena assay commonly used to assess relative levels of boldness and exploratory behaviours. Fish were subsequently lethally sampled for liver and brain mass to obtain estimates of relative body condition (hepato-somatic index, HSI) and cognitive capacity (brain-somatic index, BSI), as well as the state of the gallbladder, to test for relationships between these indices and observed boldness-related behaviours. Using principal components analysis (PCA) we identified a boldness–exploration syndrome in bluegill independent of chemical treatment and body metrics where bolder fish emerged from a start chamber in less time, travelled farther through the maze and crossed more lines than less bold fish. Bluegill exposed to kairomones were bolder on average than their counterparts in the control treatment independent of body metrics, suggesting that elevated risk levels indicated by predator kairomones can elicit behavioural responses consistent with boldness, exploration and risk taking. The role of relative cognitive ability in the expression of boldness and exploration is equivocal and may be resolved through repeated assays on individuals at different risk levels.
- Published
- 2021
33. Banded karyotypes of the Northern pike, Esox lucius (Esocidae) in Turkey
- Author
-
Atilla Arslan and Zafer Alpaslan
- Subjects
Geography, Planning and Development ,Chromosome ,Zoology ,Karyotype ,Management, Monitoring, Policy and Law ,Biology ,biology.organism_classification ,computer ,Esox ,Pike ,computer.programming_language - Abstract
In this study, cytogenetic properties of E. lucius in Sakarya River were investigated using standard Giemsa staining, C- and Ag-NOR banding techniques. The number of diploid chromosomes (2n) of individuals studied is 50 and karyotype consists of 50 acrocentric chromosomes with decreasing sizes. Secondary constriction was observed on the third autosomal pair in the karyotype. Morphologically distinguishable sex chromosomes were not detected in male and female individuals. Some chromosomes were centromeric C-positive, while some chromosomes were negative. Active NOR is localized in the pericentromeric region of the third autosomal pair and it is related to C-heterochromatin. Our results are similar to those of other studies and this result shows that the cytogenetic properties of the species are quite stable. Moreover, these results may contribute to the cytogenetic and phylogenetic studies of the Esox species in the future.
- Published
- 2020
34. Ultrastructural features of aporocotylid blood flukes: The tegument and sensory receptors of Sanguinicola inermis Plehn, 1905 from the pike Esox lucius, with a comparative analysis of their traits within the Neodermata
- Author
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Larisa G. Poddubnaya, Alexander E. Zhokhov, and David I. Gibson
- Subjects
0106 biological sciences ,Autapomorphy ,biology ,Cilium ,Sarcoplasm ,010607 zoology ,Viral tegument ,Anatomy ,biology.organism_classification ,010603 evolutionary biology ,01 natural sciences ,Spine (zoology) ,Cytoplasm ,Ultrastructure ,Animal Science and Zoology ,Esox - Abstract
This work represents the first ultrastructural study of the tegument of a freshwater teleost-infecting aporocotylid blood fluke and the first detailed observations of the surface sensory receptors of any aporocotylid. The work was carried out on Sanguinicola inermis from the branchial arteries of the pike, Esox lucius. Light and scanning electron microscopy observations failed to show the presence of protruding surface spines in S. inermis. Transmission electron microscopy studies revealed, deep beneath the distal cytoplasm of the tegument, sporadic, membrane-bound sarcoplasmic processes, each containing a single spine with the typical crystalline structure of digenean spines. On rare occasions, the spine may protrude above the body surface, but in such cases the distal tegumental cytoplasm is extremely flattened. This finding supports a unique, deep origin of aporocotylid spines when compared to those of other digenean families. This character may well prove to be an autapomorphy of the Aporocotylidae, and the position of the base of aporocotylid spines within sarcoplasmic processes supports their origin as a muscle derivative. Unlike other digenean groups, the distal region of the cytoplasmic processes, connecting sunken tegumental perikarya with the syncytial tegumental cytoplasm, is strengthened by peripheral microtubules. Three types of ciliated and three types of non-ciliated sensory receptors were distinguished in the tegument of S. inermis. One of the distinctive features of the ciliated receptors is the unusual position of the basal region of the cilium within a tegumental outgrowth. Such a position has previously been described for certain receptors types in larval and adult schistosomatids and larval diplostomids, suggesting that this feature, in adult worms, might prove to be an apomorphic trait for some or all groups of blood flukes.
- Published
- 2020
35. Population genetics of pike, genus Esox (Actinopterygii, Esocidae), in Northern Italy: evidence for mosaic distribution of native, exotic and introgressed populations.
- Author
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Gandolfi, Andrea, Ferrari, Claudio, Crestanello, Barbara, Girardi, Matteo, Lucentini, Livia, and Meraner, Andreas
- Subjects
- *
INTROGRESSION (Genetics) , *FISHERY management , *GENETIC testing , *ESOX , *BIODIVERSITY - Abstract
Esox flaviae represents the native esocid species of the Italian peninsula at present potentially highly threatened by the diffusion of exotic E. lucius. Here, we present a novel mtDNA ( N = 272) and microsatellite ( N = 275) dataset including 13 test and 3 reference samples, aimed to delineate the distribution of the native as well as the exotic species and to unravel potential introgressive hybridisation between the two species in Northern Italy. We highlight a complex mosaic distribution of both species, with contrasting occurrence even between neighbouring sites. Significant genetic substructure is still observed within E. flaviae, while the dispersal of the invader seems to be promoted by restocking actions. In addition, we prove the existence of introgressive hybridisation between native and exotic pikes. Here, gender-biased hybridisation is suggested, with native E. flaviae constituting the predominant 'mother species' in the hybridisation process. Finally, we underline the need for a revision of fisheries management regulations, for which a nation-wide and exhaustive genetic screening in the near future should build the scientific basis. [ABSTRACT FROM AUTHOR]
- Published
- 2017
- Full Text
- View/download PDF
36. Using accelerometry to quantify prey attack and handling behaviours in piscivorous pike Esox lucius.
- Author
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Deurs, M., Andersson, A., Vinterstare, J., Didenko, A., Persson, A., Brönmark, C., and Nilsson, P. A.
- Subjects
- *
PISCIVOROUS fishes , *FISH feeds , *ESOX , *ACCELEROMETRY , *PREDATION - Abstract
Accelerometer technology was used to evaluate behaviours in the teleost ambush predator pike Esox lucius foraging on crucian carp Carassius carassius. Automated rule-based estimates of prey-size determined handling time were obtained and are compared with video-recorded behaviours. Solutions to tag attachment and the limitations imposed by battery-time and data-logging capacities are evaluated. [ABSTRACT FROM AUTHOR]
- Published
- 2017
- Full Text
- View/download PDF
37. Morphological differentiation in northern pike ( Esox lucius): the influence of environmental conditions and sex on body shape.
- Author
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Senay, C., Harvey-Lavoie, S., Macnaughton, C.J., Bourque, G., and Boisclair, D.
- Subjects
- *
ESOX , *GENDER , *RIVERS , *ESOCIDAE , *PIKE - Abstract
Morphological differentiation may allow individuals to cope with prevailing environmental conditions. Morphological differentiation in fish characterized by sagittiform shape and ambush predator behaviour, such as northern pike ( Esox lucius L., 1758), has rarely been addressed. Morphological differentiation was assessed in two rivers exhibiting contrasting flow regimes: a hydropeaking river characterized by large and frequent fluctuations in flow rates and an unregulated river. An increase in northern pike movement rate was observed in the hydropeaking river. Therefore, morphological features enhancing sustained and burst swimming, as well as manoeuvrability, were expected. Our objectives are to ( i) compare morphology between the two rivers and ( ii) assess morphological differentiation between sexes. Using geometric morphometrics, shape significantly diverged between rivers irrespective of sex and between sexes in the hydropeaking river. Individuals from the hydropeaking river had more elongated heads, deeper bodies and caudal peduncles, and longer dorsal fin insertions than individuals from the unregulated river. Caudal fin differences between rivers were not consistent between sexes. Morphological differentiation suggested a trade-off among adaptations for sustained and burst swimming, as well as manoeuvrability, to cope with variable flows in a hydropeaking river. Morphological differentiation may allow the exploitation of spatially and temporally variable environmental conditions, including those stemming from river flow regulation. [ABSTRACT FROM AUTHOR]
- Published
- 2017
- Full Text
- View/download PDF
38. Facing different predators: adaptiveness of behavioral and morphological traits under predation.
- Author
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HEYNEN, Martina, BUNNEFELD, Nils, and BORCHERDING, Jost
- Subjects
- *
PREDATION , *PERCH , *ESOX , *FISH morphology , *PHENOTYPIC plasticity , *ANIMAL behavior , *FISHES - Abstract
Predation is thought to be one of the main structuring forces in animal communities. However, selective predation is often measured on isolated traits in response to a single predatory species, but only rarely are selective forces on several traits quantified or even compared between different predators naturally occurring in the same system. In the present study, we therefore measured behavioral and morphological traits in young-of-the-year Eurasian perch Perca fluviatilis and compared their selective values in response to the 2 most common predators, adult perch and pike Esox lucius. Using mixed effects models and model averaging to analyze our data, we quantified and compared the selectivity of the 2 predators on the different morphological and behavioral traits. We found that selection on the behavioral traits was higher than on morphological traits and perch predators preyed overall more selectively than pike predators. Pike tended to positively select shallow bodied and nonvigilant individuals (i.e. individuals not performing predator inspection). In contrast, perch predators selected mainly for bolder juvenile perch (i.e. individuals spending more time in the open, more active), which was most important. Our results are to the best of our knowledge the first that analyzed behavioral and morphological adaptations of juvenile perch facing 2 different predation strategies. We found that relative specific predation intensity for the divergent traits differed between the predators, providing some additional ideas why juvenile perch display such a high degree of phenotypic plasticity. [ABSTRACT FROM AUTHOR]
- Published
- 2017
- Full Text
- View/download PDF
39. Higher-order organisation of extremely amplified, potentially functional and massively methylated 5S rDNA in European pikes (Esox sp.).
- Author
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Symonová, Radka, Ocalewicz, Konrad, Kirtiklis, Lech, Delmastro, Giovanni Battista, Pelikánová, Šárka, Garcia, Sonia, and Kovařík, Aleš
- Subjects
- *
ESOX , *KARYOTYPES , *RECOMBINANT DNA , *POLYPLOIDY , *CYTOGENETICS , *DNA restriction enzymes - Abstract
Background: Pikes represent an important genus (Esox) harbouring a pre-duplication karyotype (2n = 2x = 50) of economically important salmonid pseudopolyploids. Here, we have characterized the 5S ribosomal RNA genes (rDNA) in Esox lucius and its closely related E. cisalpinus using cytogenetic, molecular and genomic approaches. Intragenomic homogeneity and copy number estimation was carried out using Illumina reads. The higher-order structure of rDNA arrays was investigated by the analysis of long PacBio reads. Position of loci on chromosomes was determined by FISH. DNA methylation was analysed by methylation-sensitive restriction enzymes. Results: The 5S rDNA loci occupy exclusively (peri)centromeric regions on 30-38 acrocentric chromosomes in both E. lucius and E. cisalpinus. The large number of loci is accompanied by extreme amplification of genes (>20,000 copies), which is to the best of our knowledge one of the highest copy number of rRNA genes in animals ever reported. Conserved secondary structures of predicted 5S rRNAs indicate that most of the amplified genes are potentially functional. Only few SNPs were found in genic regions indicating their high homogeneity while intergenic spacers were more heterogeneous and several families were identified. Analysis of 10-30 kb-long molecules sequenced by the PacBio technology (containing about 40% of total 5S rDNA) revealed that the vast majority (96%) of genes are organised in large several kilobase-long blocks. Dispersed genes or short tandems were less common (4%). The adjacent 5S blocks were directly linked, separated by intervening DNA and even inverted. The 5S units differing in the intergenic spacers formed both homogeneous and heterogeneous (mixed) blocks indicating variable degree of homogenisation between the loci. Both E. lucius and E. cisalpinus 5S rDNA was heavily methylated at CG dinucleotides. Conclusions: Extreme amplification of 5S rRNA genes in the Esox genome occurred in the absence of significant pseudogenisation suggesting its recent origin and/or intensive homogenisation processes. The dense methylation of units indicates that powerful epigenetic mechanisms have evolved in this group of fish to silence amplified genes. We discuss how the higher-order repeat structures impact on homogenisation of 5S rDNA in the genome. [ABSTRACT FROM AUTHOR]
- Published
- 2017
- Full Text
- View/download PDF
40. The Effect of Aluminium and Iron-Based Coagulants Used for Lake Recultivation on the Sperm Motility and Fertilisation of the Pike (Esox lucius L.).
- Author
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Bonisławska, M., Nędzarek, A., Szulc, J., Tański, A., and Tórz, A.
- Subjects
- *
FISH fertility , *ESOX , *EFFECT of water pollution on fishes , *PIKE fisheries , *ALUMINUM , *COAGULANTS , *SPERM motility , *SEMEN analysis - Abstract
The objective of the research was to test the effect of iron and aluminium coagulants commonly used for lake re-cultivation, on the pike sperm motility and fertilisation. The coagulants caused changes in the analyzed hydrochemical parameters of the water such as: Fe, Mg2+, TSS, SO42- and Cl-. Selected parameters of sperm motility: MOT, VCL, VSL, VAP, LIN were estimated using CASA. The sperm motility at the moment of activation was the highest in the control sample. With increasing the time of exposure the proportion of sperm motility in the analyzed semen decreased. In the samples with coagulants the values of MOT, VCL and VSL were smaller than in the control sample (statistically significant differences between the control and the samples with PIX and PAX were recorded in the 25th-30th second after activation). The percentage of fertilised eggs was the greatest in the control sample and in the PAX®18 sample (73.11 and 70.42%, respectively), whereas in the PIX®113 it was less than that (54.88%). The shortest larvae were those in the sample with coagulant PIX®113. In the samples with PIX®113 and PAX®18 the survivorship of embryos compared to the control sample was the smallest (43.10 and 51.61%, respectively and control 67.60%) and the proportion of malformed larvae was the highest (34.82 and 24.52%, respectively and control 15.17%). [ABSTRACT FROM AUTHOR]
- Published
- 2017
41. Temporally stable, weak genetic structuring in brackish water northern pike ( Esox lucius) in the Baltic Sea indicates a contrasting divergence pattern relative to freshwater populations.
- Author
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Wennerström, Lovisa, Olsson, Jens, Ryman, Nils, and Laikre, Linda
- Subjects
- *
SPATIOTEMPORAL processes , *POPULATION genetics , *ANIMAL populations , *ESOX , *ESOCIDAE - Abstract
Understanding spatiotemporal population genetic patterns is important for conservation management of ecologically and socioeconomically important species. This is particularly so in species-poor environments such as the brackish Baltic Sea. We examined over 600 northern pike ( Esox lucius), a coastal predator and treasured sport fish, collected over major parts of the Baltic Sea coastline. We found low genetic divergence among populations, indicating a contrasting genetic structure of brackish water coastal spawners compared with previous reports on anadromous Baltic pike migrating up freshwater streams for spawning. A pattern of genetic isolation by distance either over shortest waterway or primarily along the mainland coast with islands as stepping stones suggested that gene flow is primarily taking place among neighboring populations, possibly with some migration over open water. Temporal data showed a stable genetic structure over a decade. Within a single sampling year, however, spatial divergence was larger during spawning than feeding season, indicating increased mixing of populations during the feeding season. Management should assure connectivity among brackish spawning grounds and large population sizes at identified core areas. [ABSTRACT FROM AUTHOR]
- Published
- 2017
- Full Text
- View/download PDF
42. A review of Neogene and Quaternary pikes of southeastern Europe and a new species from the early Pleistocene of Nogaisk, Ukraine.
- Author
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KOVALCHUK, OLEKSANDR M., WILSON, MARK V. H., and GRANDE, TERRY
- Subjects
- *
NEOGENE Period , *ESOX , *MORPHOLOGY , *ANIMAL morphology , *ESOCIDAE , *FISH morphology - Abstract
The fish genus Esox (Teleostei, Esocidae) has been recorded from thirty late Miocene, Pliocene, and Pleistocene localities where forty-one bone-bearing strata are exposed in the territory of Ukraine, Russian Federation, and Republic of Moldova. From eight localities the genus is reported or described for the first time. A detailed description and morphological analysis of the currently available osteological material demonstrates the presence of four species in the studied area: (i) Esox sibiricus (late Miocene-early Pliocene); (ii) Esox moldavicus (early Pliocene-early Pleistocene); (iii) Esox nogaicus sp. nov. (early Pleistocene, Calabrian); (iv) Esox lucius (early-middle Pleistocene). The Northern Pike (Esox lucius) is recorded for the first time in the early Pleistocene fossil record of southeastern Europe. The new species E. nogaicus is characterized by a massive dentary with deep symphysis and the possible presence of a pair of fixed canine-like teeth near the anterior end of the vomer. Such canine teeth are seen also in certain species known only from North America, the extant Esox masquinongy, the fossil species E. columbianus, and an unnamed Miocene form. However, unlike in E. nogaicus, in the three North American species fixed canines also occur anteriorly on the palatines. The Miocene, Pliocene, and Pleistocene pikes from southeastern Europe document a greater diversity of morphologies in the past than exists today in the pike species of Europe. Changes in the predominant species of Esox in southeastern Europe are hypothesized to be driven by changing global and regional climates. [ABSTRACT FROM AUTHOR]
- Published
- 2017
- Full Text
- View/download PDF
43. Pike ( Esox lucius L.) on the edge: consistent individual movement patterns in transitional waters of the western Baltic.
- Author
-
Jacobsen, Lene, Bekkevold, Dorte, Berg, Søren, Jepsen, Niels, Koed, Anders, Aarestrup, Kim, Baktoft, Henrik, and Skov, Christian
- Subjects
- *
ESOX , *EFFECT of saline waters on fishes , *FISH spawning , *FISH reproduction , *FISH physiology ,FISH & climate - Abstract
Pike in the western Baltic Sea live on the edge of their salinity tolerance. Under physiologically challenging conditions, organism may respond by moving to environmentally more benign areas during critical periods, such as during spawning. We hypothesised that pike in a brackish lagoon (8-10 ppt salinity) would perform spawning- and feeding-related movements between areas with different salinity regimes. Twenty-two pike were caught prior to spawning, tagged with acoustic transmitters, and their movements were tracked for 18 months. Pike showed two main patterns of movements that were consistent within individuals across two years. Whereas some individuals stayed in the lagoon year-round, most pike left the lagoon for longer periods after spawning and returned to the lagoon prior to following year's spawning season. We found no evidence that probability of moving out of the lagoon co-varied with either length or condition factor. Despite the fact that the lagoon's salinity is close to the reported upper limit for pike egg development, results indicated that all pike spawned in the lagoon. Correspondingly, genetic data showed that all fish belonged to the same reproductive population unit. Movement patterns thus appear to reflect individual variation in home-range and/or resource optimisation following ideal free principles. [ABSTRACT FROM AUTHOR]
- Published
- 2017
- Full Text
- View/download PDF
44. Living in the edge: the fate of individually marked pike ( Esox lucius ) stocked in a hyper-eutrophic lake with frequent winter hypoxia.
- Author
-
Lappalainen, Jyrki, Vinni, Mika, and Malinen, Tommi
- Subjects
- *
EUTROPHICATION , *FISH populations , *HYPOXIA (Water) , *FISH kills , *ESOX , *ICE sheets - Abstract
Eutrophication of lakes has increased the risk of fish kills during winter under ice cover. If such a lake is isolated, the fish assemblage consists of only oxygen-tolerant species without predatory species. Here, our main aim was to analyze the fate of 99 marked pike (Esox lucius) stocked to a pikeless lake that is known to have low oxygen concentrations under ice cover. These pike (total lengths 33.5–76.9 cm; weights 260–3050 g) were stocked in May 2008 and were followed 7 years. The first marked pike was caught in August 2008 and the last one in September 2012. Between these dates, 21 pike were caught at least once, five pike were caught twice, and two pike were caught three times. Relative condition was based on the length–weight relationship. Both length and weight affected significantly the recapture probability, whereas relative condition had no effect. The growth of marked pike was estimated based on length or weight increments in two separate models with either starting length or weight together with the number of days between observations. In these models, the number of days had positive, and size, either length or weight, had a negative relationship with growth. According to marginalr2, length and the number of days explained 65.5% of variation in length increments, whereas the marginalr2for weight and the number of days was 49.3% for weight increments. The length increment model was used to compare pike growth in Lake Savijärvi with other Finnish lakes. The comparison showed that during the first four growing seasons after stocking, the pike growth in Lake Savijärvi was faster than in the other lakes studied. [ABSTRACT FROM PUBLISHER]
- Published
- 2016
- Full Text
- View/download PDF
45. Behavioural and fitness effects of translocation to a novel environment: Whole‐lake experiments in two aquatic top predators
- Author
-
Bernard Chéret, Erik Eschbach, Philipp Czapla, Daniel Hühn, Robert Hagemann, Christopher T. Monk, Thomas Klefoth, and Robert Arlinghaus
- Subjects
0106 biological sciences ,media_common.quotation_subject ,Fisheries ,Zoology ,Biology ,010603 evolutionary biology ,01 natural sciences ,Competition (biology) ,Predation ,Stocking ,Fish stocking ,Animals ,Catfishes ,Ecology, Evolution, Behavior and Systematics ,Esox ,Pike ,computer.programming_language ,media_common ,Apex predator ,Reproductive success ,010604 marine biology & hydrobiology ,biology.organism_classification ,Lakes ,Predatory Behavior ,Esocidae ,Animal Science and Zoology ,computer - Abstract
Translocation into a novel environment through common fisheries management practices, such as fish stocking, provides opportunities to study behavioural and fitness impacts of translocations at realistic ecological scales. The process of stocking, as well as the unfamiliarity with novel ecological conditions and the interactions with resident fish may affect translocated individuals, leading to alterations of behaviours and causing fitness impacts. Our objectives were to investigate how aquatic top predators behaviourally establish themselves and compete with resident individuals following introduction in a novel lake environment and to investigate the resulting fitness consequences. Using high-resolution acoustic telemetry, we conducted whole-lake experiments and compared the activity, activity-space size and fate of translocated and resident individuals in two model top predators, the northern pike Esox lucius (n = 160) and European catfish Silurus glanis (n = 33). Additionally, we compared the reproductive success of translocated and resident northern pike. The experiment was conducted with large (adult) individuals of different origins, resilient to predation, but subject to agonistic interactions and competition with resident fish. Over a period of several months, the translocated catfish exhibited consistently larger activity-space sizes than resident catfish, but did not differ from residents in activity and survival. The pike from one of the two translocated origins we tested also showed elevated space-use, and both translocated origins revealed higher mortality rates than their resident conspecifics, indicating maladjustment to their novel environment. When non-resident pike reproduced, they overwhelmingly produced hybrid offspring with resident fish, indicating that introductions fostered gene flow of non-native genes. Our study indicates that fish introductions result in behavioural and fitness impacts even in large-bodied top predators that experience low levels of natural predation risk.
- Published
- 2020
46. Shape, condition and diet of the pike icefish Champsocephalus esox (Teleostei: Channichthyidae): evidence of phenotypic plasticity?
- Author
-
Mauricio F. Landaeta, Mathias Hüne, and Ariel Villegas
- Subjects
0106 biological sciences ,Morphometrics ,Phenotypic plasticity ,Teleostei ,biology ,010604 marine biology & hydrobiology ,Fish fin ,Zoology ,Geology ,Oceanography ,biology.organism_classification ,010603 evolutionary biology ,01 natural sciences ,Channichthyidae ,Patagonotothen ,Snout ,Ecology, Evolution, Behavior and Systematics ,Esox - Abstract
The shape (derived from landmark-based geometric morphometrics), condition (Fulton index) and diet (determined through gut content analysis) were described for the pike icefish Champsocephalus esox (Channichthyidae) from Última Esperanza sound, south-west Patagonia, Chile. Based on the length-weight relationship, females were heavier at length than males. Nevertheless, the Fulton index was similar between males and females. The morphospace of C. esox showed high intraspecific variability in the dorsoventral position of the tip of the snout, anus and the ventral insertion of the pectoral fin, as well as the anteroposterior position of the premaxilla, opercle and anus. This indicates the existence of phenotypic plasticity, leading to specimens with larger jaws and heads but shorter trunks, or specimens with shorter jaws and heads but larger trunks. This phenotypic plasticity was independent of size and sex. The feeding incidence was similar between sexes (34.1% and 47.2% for males and females, respectively). Diets consisted of only fish, small notothenioids of the genus Patagonotothen (P. tessellata, P. cornucola and P. sima), showing similarities between males and females. Finally, C. esox is the second notothenioid species, and the first outside of Antarctica, to display phenotypic plasticity in its body shape.
- Published
- 2020
47. The influence of endogenous cathepsin in different subcellular fractions on the quality deterioration of Northern pike (Esox lucius) fillets during refrigeration and partial freezing storage
- Author
-
Chengjian Xu, Jian Zhang, Xin Guo, Hengheng Qiu, Xiaoying Mao, Xiaobing Guo, and Xiaorong Deng
- Subjects
Cathepsin ,biology ,Chemistry ,Refrigeration ,Endogeny ,Protein oxidation ,biology.organism_classification ,Applied Microbiology and Biotechnology ,Article ,Cathepsin B ,Food science ,Myofibril ,computer ,Esox ,Food Science ,Biotechnology ,Pike ,computer.programming_language - Abstract
The purpose of this study was to investigate the endogenous cathepsin activity in each subcellular fraction and the effect of this activity on myofibrillar protein and texture during refrigeration and partial freezing storage of northern pike (Esox lucius) fillets. The results showed that fillets stored under the refrigerated condition were more susceptible to oxidation than partial freezing. Endogenous cathepsin activity indicated that partial freezing destroys the integrity of lysosomes more effectively than refrigeration and inhibits the increase in cathepsin B and B + L in lysosomes. The activity of cathepsin B and B + L in lysosomes, mitochondria and myofibrils under the partial freezing conditions was always lower than that under refrigeration. Texture analysis showed that refrigeration had a negative impact on hardness and springiness. In conclusion, the cathepsin activity in each subcellular fraction was effectively inhibited and better textural characteristics were obtained with partial freezing than refrigeration. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (10.1007/s10068-020-00781-z) contains supplementary material, which is available to authorized users.
- Published
- 2020
48. Extent of injury and mortality arising from entrainment of fish through a Very Low Head hydropower turbine in central Ontario, Canada
- Author
-
Erik I. Tuononen, Evan R. Timusk, Steven J. Cooke, and Karen E. Smokorowski
- Subjects
Minimal risk ,biology ,business.industry ,Fish species ,Aquatic Science ,biology.organism_classification ,Turbine ,Fishery ,Environmental science ,Entrainment (chronobiology) ,business ,computer ,Esox ,Hydropower ,Pike ,computer.programming_language ,Ontario canada - Abstract
Because of growing interest in deploying newer very low head (VLH) turbine technology to generate electricity in rivers, there is a need to assess how fish fare in interactions with VLH turbines. We assessed injury and mortality rates from experimental VLH turbine entrainment of fish species local to the study site at Wasdell Falls on the Severn River, Ontario, which is one of the first such VLH installations in North America. Using balloon tags to recapture fish and before/after entrainment assessments, we found minimal injury and mortality differences between control (no entrainment) and treatment (entrainment) groups. One adult northern pike (Esox lucius Linnaeus, 1758; 1.16% of total entrained fish) was killed by turbine strike. Abrasion-related injuries (i.e., scale loss, torn fins) were the most common form of injury in both control and treatment fish, which was likely attributed to handling and not turbine passage per se. Telemetry monitoring of a subset of fish revealed that post-passage mortality was low. These results suggest that VLH turbine entrainment has negligible effects on the fish species studied here, and thus, VLH turbines may be suitable for increasing generating capacity at low head dam sites with minimal risk to fish.
- Published
- 2020
49. Positive temperature effects on the initiation and intensity of cannibalistic behaviour of larval pike, Esox lucius L. Is cannibalism reflected in otolith fluctuating asymmetry?
- Author
-
Dariusz P. Fey and Martyna Greszkiewicz
- Subjects
0106 biological sciences ,Larva ,biology ,010604 marine biology & hydrobiology ,Cannibalism ,Zoology ,04 agricultural and veterinary sciences ,Aquatic Science ,biology.organism_classification ,01 natural sciences ,Fluctuating asymmetry ,Predation ,medicine.anatomical_structure ,040102 fisheries ,medicine ,0401 agriculture, forestry, and fisheries ,Predator ,computer ,Esox ,Otolith ,Pike ,computer.programming_language - Abstract
Cannibalism can be a significant factor limiting the survival of pike, Esox lucius, early life stages in both natural and aquaculture conditions. In the present research, type I cannibalism was studied in pike larvae (size range: 9–32.5 mm standard length, SL) in controlled conditions for 45 days post-hatching (dph). For this purpose, the occurrence of cannibalistic pairs, i.e. prey caught by a cannibal inside the cannibal’s mouth, was monitored for 15 min periods by two observers six times daily. Cannibalism was not observed in fish that still had yolk-sacs, but it did occur as soon as the yolk-sac was absorbed on 5 dph at a body size of 13 mm at 22 °C and 10 dph at a body size of 13.4 mm at 15 °C. The ratio of prey to predator size was on average 87%, but the smallest observed size difference was only 1.3%. The intensity of cannibalistic attacks depended on water temperature with more intense cannibalism at 22 °C than at 15 °C, and no cannibalism at 10 °C. Fluctuating asymmetry (FA) in all three sagittal otolith size parameters (area, width, and length) was higher in prey than in cannibals, the differences were not statistically significant.
- Published
- 2020
50. ОСОБЛИВОСТІ ОСМОТИЧНОЇ РЕЗИСТЕНТНОСТІ ЕРИТРОЦИТІВ ТА ВМІСТУ ГЕМОГЛОБІНУ У КРОВІ РИБ ЗА ДІЇ ФЕРУМУ (III)
- Author
-
V. V. Futryk, O. O. Rabcheniuk, V. Z. Kurant, and V. O. Khomenchuk
- Subjects
biology ,Chemistry ,Physiological condition ,biology.organism_classification ,Cyprinus ,Pigment ,Membrane ,visual_art ,visual_art.visual_art_medium ,sense organs ,Food science ,Hemoglobin ,Carp ,computer ,Esox ,Pike ,computer.programming_language - Abstract
The osmotic resistance of erythrocytes and the content of hemoglobin in the blood of carp (Cyprinus carpio L.) and pike (Esox lucius L.) under the action of Fe3+ ions at concentrations of 0.2 and 0.5 mg/dm3, were under study which corresponded to 2 and 5 maximum permissible concentration (MPC). The research demonstrated that increased concentrations of Fe3+ ions lead to changes in the osmotic resistance of erythrocytes and the content of hemoglobin in the blood of carp and pike. The findings suggest that high concentrations of Iron (5 MPC) in carp lead to a decrease in the resistance of erythrocyte membranes, and in pike it led to increased osmotic resistance of erythrocytes, which is apparently due to different mechanisms of adaptation of fish erythrocyte membranes to adverse aquatic environment. Species-specificity is also characterized by changes in the content of hemoglobin in the blood of fish species which were researched. An increased amount of pigment in the blood of carp and a decreased amount of hemoglobin in pike under the action of 5 MPC of metal ions was established. The obtained results can be used to assess the physiological condition of fish and water quality under conditions of contamination of watercourses with metals.
- Published
- 2020
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