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The marine thecate dinoflagellate Azadinium includes species known to produce the diarrhetic shellfish toxins known as azaspiracids (AZAs). In this study, the morphology of a thecate dinoflagellate isolated from Mutsu Bay, Japan, was examined by LM and SEM, and its phylogenetic position was inferred from ITS and LSU rDNA sequences. The production of AZAs was examined by liquid chromatography-triple quadrupole mass spectrometer (LC-MS/MS). Cells were elliptical, 15.9–22.4 µm long and 11.1–17.1 µm wide. A chloroplast was positioned peripherally, with a pyrenoid near the cingulum, and the nucleus was placed in the hyposome. The hyposome was smaller than the episome, with an antapical spine on plate 2''''. Thecal tabulation was Po, cp, X, 4', 3a, 6'', 6C, 5S, 6''', 2''''. The apical pore complex consisted of a symmetrical apical pore plate (Po), a cover plate (cp) and a small canal plate (X), and was surrounded by a prominent collar formed by the apical plates. A ventral pore was located on the mid-anterior edge of plate 1' and contacted with the X-plate and/or the ventral left of plate Po. Plate 1'' was in contact with plate 1a. AZA was not detected in the cultures. Molecular phylogeny showed that the species was related to Azadinium species that possess the ventral pore on the left side of plate 1', i.e. A. cuneatum, A. dalianense, A. obesum, A. poporum, A. spinosum and A. trinitatum, but that it was not included in these species. The new species Azadinium anteroporum sp. nov. differs in the ventral pore position (mid-anterior edge of plate 1') from these related species (which have the ventral pore on the left side of plate 1'), and from A. polongum (with ventral pore on the posterior left side of 1') and all other Azadinium species (with ventral pore on the right side of 1'). [ABSTRACT FROM AUTHOR]

Equoid perissodactyls were diverse in the Eocene of the Iberian Peninsula, and those from the central and western Iberian basins (Mondego, Oviedo, Almazán, Duero, and Miranda-Treviño) and the eastern Ebro Basin (Ulldemolins area) were endemic, with the presence of six genera and 19 species (mainly Palaeotheriidae sensu stricto) that are unknown in the rest of western Europe. In this paper, a new endemic Eocene paleotheriid genus, Idiodontherium, gen. nov., is reported. The new genus includes two species: I. martindejesusi, from the upper middle Eocene (Bartonian) of Mazaterón (Almazán Basin, Soria, Spain) and I. astibiai, from the upper Eocene (Priabonian) site of Zambrana (Miranda-Treviño Basin, Álava/Araba, Spain). Idiodontherium exhibits an unusual dental pattern, which is characterized by an extreme shortening of the jugal series due to a great reduction of the premolar series, in combination with a long post-canine diastema. It is a small to medium-sized plagiolophine with thick enamel in comparison with other plagiolophine equoids of the same size. These new taxa exhibit peculiar dental features that could be associated with greater specialization of the diet. [ABSTRACT FROM AUTHOR]

Southern mullet Chelon richardsonii is one of the important fish species found in the Walvis Bay lagoon (WBL) that is commercially exploited for local consumption. The southern mullet is, however, exposed to mercury (Hg) found in sediments, which forms part of its diet. This study evaluated the Hg concentration in muscles, stomach content, liver, and gills of C. richardsonii over two years. The Hg concentration was higher in the liver (0.005 mg kg−1) and relatively lower in the gills (0.001 mg kg−1). There were temporal variations in Hg concentration among the tissues; a positive correlation between mean Hg concentration and fish sizes (total length and total weight) was documented in the gills; and a negative correlation for size versus Hg concentration was recorded in the livers, stomach contents, and the muscles of southern mullets. The Hg concentrations of all tissues were below the World Health Organisation (WHO) limit for fish (0.5 mg kg−1), which indicates that it does not pose a human health risk at the current levels. This study's findings form a baseline for using southern mullets as biological indicators of Hg pollution in WBL. The study also highlights the need for regular monitoring programmes to protect and maintain the ecological characteristics of WBL as per Namibia's mandates under the Ramsar Convention. [ABSTRACT FROM AUTHOR]

Equoid perissodactyls were diverse in the Eocene of the Iberian Peninsula, and those from the central and western Iberian basins (Mondego, Oviedo, Almazán, Duero, and Miranda-Treviño) and the eastern Ebro Basin (Ulldemolins area) were endemic, with the presence of six genera and 19 species (mainly Palaeotheriidae sensu stricto) that are unknown in the rest of western Europe. In this paper, a new endemic Eocene paleotheriid genus, Idiodontherium, gen. nov., is reported. The new genus includes two species: I. martindejesusi, from the upper middle Eocene (Bartonian) of Mazaterón (Almazán Basin, Soria, Spain) and I. astibiai, from the upper Eocene (Priabonian) site of Zambrana (Miranda-Treviño Basin, Álava/Araba, Spain). Idiodontherium exhibits an unusual dental pattern, which is characterized by an extreme shortening of the jugal series due to a great reduction of the premolar series, in combination with a long post-canine diastema. It is a small to medium-sized plagiolophine with thick enamel in comparison with other plagiolophine equoids of the same size. These new taxa exhibit peculiar dental features that could be associated with greater specialization of the diet. [ABSTRACT FROM AUTHOR]

Morphology of the fish and otoliths are popularly used in the discrimination of species/stocks/populations and also to gather meaningful conclusions about their ecology. This approach is useful to enhance our understanding of the relationship between form and function in fishes when a direct assessment is impossible. Inter-species variation was analysed using geometric morphometric analysis for fish body shape, while morphometry and wavelet functions for sagittae morphology. A clear ecomorphological pattern in the body, as well as otolith shape, is evident among species as deeper inhabiting species possess a deeper body with oblong otoliths compared with shallower species that possess a more streamlined body with fusiform otoliths. We also observed that deeper species (P. obscura) possess bigger eyes for the optimum use of available light and bigger otoliths with higher otolith sensory area and otolith area ratio (S:O) for better sound reception capacities. Our hypothesis supports that the differences in fish morphological as well as sensorial traits (otoliths), which are closely related to their locomotion, foraging pattern and depth of habitation, lead to trophic segregation which in turn encourages their coexistence. This is the first work that discusses the relationship between body shape, otolith morphometry and morphology in deep-sea fishes and their ecomorphological interpretations. [ABSTRACT FROM AUTHOR]

In the context of a taxonomic revision of the tribe Pleuroweisieae in South America, we studied a specimen of Hymenostylium that did not match any previously known species of this genus in America. Here we present our arguments for recognising this moss as a new species. The morphology of the potential new species was compared with that of the species of Hymenostylium presently recognised. A phylogenetic analysis based on the nuclear ITS and plastid rps4 regions was performed to investigate relationships between the new species and closely related taxa. Based on morphological and molecular data, we describe this new species from Brazil, Hymenostylium chapadense M.J.Cano & J.A.Jiménez. The species is strikingly distinguished by a stem with central strand and hyalodermis, oblong-ligulate to oblong-elliptical leaves that are when dry slightly crisped in the upper part and usually constricted just above the base and recurved on one side in the lower third, with uni- to bistratose margins, obtuse apex, costa wide and ending below the apex or percurrent with ventral and dorsal surface cells of the costa differentiated as an epidermis, and middle laminal cells usually with a simple, coarse, central papilla. Our molecular study placed H. chapadense as sister to H. hildebrandtii (Müll.Hal.) R.H.Zander. Possible confusion with the latter species and other closely related taxa is discussed. A key to the South American species of Hymenostylium is provided. [ABSTRACT FROM AUTHOR]

New data on faunistics, ecology and morphology of two weevil species collected from the semi-aquatic habitats in Aras River valley were obtained. Arthrostenus spadiceus Boheman, 1836 is recorded for the first time from Turkey. New data on species feeding and reproduction are provided and illustrated with digital images. Typha latifolia L. is reported for the first time as its host plant. Additionally, a single female of Arthrostenus fullo Boheman, 1836 has been captured with light trap in the same territory. The morphology of the terminalia segments and genitalia of these two species are described and illustrated for the first time. [ABSTRACT FROM AUTHOR]

Benzophenone-3 (BP-3) is a common component of organic sunscreen widely used that can affect especially aquatic ecosystems health, including fish. To verify the biological effects of low concentrations of BP-3 on blood cells, one hundred and forty zebrafish (D. rerio) were used and then randomly divided into five groups: control group (water), solvent group (alcoholic water), and BP-3 group (BP-3 at 7 µg L−1, BP-3 at 70 µg L−1, and BP-3 at 700 µg L−1). The blood slices were stained with Panoptic stain and with Giemsa solution for the hematological analysis. During the exposure to BP-3, no behavioral changes were observed. Although no significant difference in total leukocytes occurred, an increase in neutrophils and a reduction of lymphocytes at the highest concentration on both 7th and 14th days were detected. The total and cytoplasmic area of erythrocytes on the 7th day at the highest concentration were reduced. In addition, alterations on the erythrocyte nuclear morphology in fish exposed to BP-3 were usually visualized, mainly when considered the occurrence of blebbed nucleus and micronucleus, indicating that BP-3 exhibits cytotoxic and mutagenic effects. The results indicate that BP-3 can interfere with the morphophysiology of aquatic organisms. [ABSTRACT FROM AUTHOR]

Chondrichthyan egg cases are important elements for species-specific identification and also provide a valuable aid in determining a species spatial distribution, as well as for defining spawning areas. Considering the absence of a general key for the identification of the egg cases of the Mediterranean Chondrichthyes, this work aims to fill this gap by presenting a species-specific key based on morphological features of the egg case. The key was developed primarily analysing fresh egg cases dissected from the oviduct, egg cases collected from the seabed or found dried lying on the seashore, after species confirmation by DNA analysis. Original data were integrated with information scrutinized from literature. In order to improve species identification, a protocol for the standardized acquisition of morpho-biometric and meristic features is also provided as a pre-requisite for the appropriate use of the identification key. The total width and length included the horns, when they are not broken, are the parameters that best explain the assignment of the egg case to a specific species. [ABSTRACT FROM AUTHOR]

We describe a new specimen attributed toMacranhinga ranzii, a taxon whose holotype is a left femur, being collected from rocks in the Solimões formation, Southwestern Amazon. The new material is an almost complete pelvic girdle and synsacrum (UFAC 6471), collected in a new fossiliferous locality named Cajueiro. The compatibility between the diameter of foramen acetabuli of UFAC 6471 with the caput femoris of the holotype and the synapomorphies present in the specimen allowed us to attribute it to M. ranzii and emend the diagnosis for this species. Based on three linear measurements of the pelvic girdle and the medium weight of extant Anhinga, we estimate the adult animal's body mass at 8.6 kg. The phylogenetic inference resulted in two equally probable evolutionary hypotheses: one of them with a monophyletic Macranhinga and in the other Meganhinga chilensis as the sister clade of a Macranhinga (in part) plus Anhinga clade. In both scenarios, Macranhinga ranzii is closely related to G. kiyuensis. The morphological and myological data gained in this study enabled us to recognise Macranhinga ranzii as a proficient swimmer and diver, and consequentially a skilled fish hunter in deep waters. [ABSTRACT FROM AUTHOR]

While the holotype of Temnodontosaurus crassimanus still remains on display at the Yorkshire Museum, it has remained largely understudied and the validity of the species has long been questioned. Through re-examination, this study highlights several morphological features of the postcranial skeleton and determines that T. crassimanus is a valid species of the genus and includes several distinct characters that can be used to distinguish it from T. trigonodon, to which it was once assigned. These include a large, robust humerus that is proximodistally longer than the scapula (scapula length vs humerus length ratio: ~0.68); forefins which are significantly longer but less than twice the length of the hindfin (forefin length vs hindfin length ratio: ~1.51); the relative size of the forefins compared with the total body length; along with several other characters that may prove to be unique, such as humerus distal width almost equal to humerus length; presence of notching in at least five leading edge elements of both the fore- and hindfins; and anteroposteriorly wider fore- and hindfins compared with T. trigonodon. Additional specimens, previously tentatively assigned to T. crassimanus, were located and examined, but none could confidently be assigned to the species. [ABSTRACT FROM AUTHOR]

The stygobiontic genus Texicerberus gen. nov. and the three species T. amistad sp. nov., T. schotteae sp. nov., and T. castilloi sp. nov. are described from freshwater aquifer or hyporheic sites across central and western Texas, USA. The status of the new genus and species is based on morphological characters that distinguish them from all other described Microcerberidae from both marine and freshwater environments. Cephalon without rostral projection, coxae II–IV rounded, medial margin of antenna article 3 angulate but not produced as spine, male pleopod II endopod uniramous, and male pleopod IV biramous are among the characters that distinguish Texicerberus gen. nov. from other genera in the family. Collected from deep karst aquifer wells, karst springs, and the hyporheic zone along the Rio Grande (Rio Bravo del Norte), these three new species represent the first documented occurrences of Microcerberidae in Texas and substantially increase the described diversity in the family in North America and from freshwater environments globally. Additional sampling, especially in the hyporheic zone, is expected to reveal additional diversity in Texas. Future collection and analysis of molecular data will be required to understand the evolutionary relationships among these and other species. [ABSTRACT FROM AUTHOR]

Sexual dimorphism of fish morphology, physiology and behavior is diverse and complex in nature. Doublesex and mab-3 related transcription factor (Dmrt) is a large protein family whose function is sexual development and differentiation in vertebrates. Here, we report a full-length cDNA sequence of Labeo rohita (rohu) Dmrt1 of 907 bp length having 798 bp of open reading frame encoding 265 amino acids. The molecular weight of rohu DMRT1 protein was found to be 28.74 KDa and isoelectric point was 7.53. DMRT1 protein contains 23 positively and 24 negatively charged amino acids with a GRAVY score of -0.618. A characteristic DM domain was found in DMRT1 protein, which is a novel DNA-binding domain. Phylogenetic analysis showed maximum similarity with Cyprinus carpio when compared with DMRT1 of other vertebrates. Molecular docking study identified active sites to be targeted for drug designing. Rohu DMRT1 was observed to interact with other proteins such as FOXL2, CYP19a1a, AMH and SOX9a. Differential expression study revealed higher expression in testis tissue implying its role in male sex differentiation and testicular development. The information generated in the present work could facilitate further research to resolve the issues related to gonadal maturation and reproduction of commercially important aquaculture species. [ABSTRACT FROM AUTHOR]

Snappers are marine fishes that inhabit reef ecosystems and have a wide distribution throughout tropical and subtropical waters of the Atlantic, Indian and Pacific Oceans. These species are resources of economic importance, there is a lack of biological and ecological knowledge about these species in the studied area, and their meat is highly valued for human consumption. To contribute to the ecological knowledge, this work reports on the feeding habits of four species of snapper: Lutjanus synagris, Lutjanus griseus, Lutjanus analis and Lutjanus apodus, through the identification of stomach contents and a similarity analysis for the diets. Results showed that the most important prey items were crustaceans. Differences were found in the consumption of specific prey: Portunus were mainly consumed by L. griseus; Cronius was consumed by L. apodus; and Pitho was consumed by L. analis and L. synagris. Identification of prey species to genus and species levels allowed the characterization of the feeding habits of these sympatric species and highlighted the need for research programmes focused on crustaceans that guarantee their availability and abundance in the ecosystem. [ABSTRACT FROM AUTHOR]

Three new species of Parabathynellidae (Crustacea: Bathynellacea) are described using morphological and molecular data, and additional populations identified as Texanobathynella cf. bowmani are placed within a molecular phylogeny for the group. The finding of Montanabathynella pecosensis sp. nov. entails a southern range expansion of over 1500 km for the genus, previously thought to be restricted to Montana, USA. Montanabathynella pecosensis sp. nov. displays a unique combination of morphological features, including eight main teeth on the labrum; four and six teeth on the pars incisiva and pars molaris of the mandible, respectively; eight teeth on the distal endite of MxI; epipod present on ThII and III; four teeth on the first segment of female ThVIII; and an unpronounced anal operculum. The other two new species described here belong to the genus Texanobathynella Delamare Deboutteville et al., 1975, previously consisting of only two species. Both species, Texanobathynella aaronswinki sp. nov and T. coloradoensis sp. nov., display combinations of morphological features distinct from the other two previously known species of the genus. Mitochondrial (COI) and nuclear (18S) markers support the validity of the new species and enable us to place them, along with T. cf. bowmani, within a larger phylogenetic framework of the Parabathynellidae. [ABSTRACT FROM AUTHOR]

In this study, we elucidated the phylogenetic position of a Pacific species Pronoprymna petrowi, a Caspian species Pronoprymna ventricosa, an Antarctic species of the genus Steringophorus, S. liparidis, and a new species of the same genus, S. occidentalipacificus sp. nov. The new species was found in a bathylagid fish Leuroglossus schmidti from the Sea of Okhotsk. Steringophorus occidentalipacificus sp. nov. is similar to S. congeri, and differs from it in the length of the body and the forebody, the shape of the testes, the sucker-ratio, the size of eggs and the extension of the caeca and the cirrus-sac. The 28S rRNA gene-based analyses supported a sister relationship between Pr. petrowi and Pr. ventricosa, and put the genus Pronoprymna into to the group of faustulids (sensu lato), which is nested within the Gymnophaloidea clade. Based on the results of these analyses, Steringophorus is identified as a paraphyletic taxon within the Fellodistomidae (Gymnophalloidea). Phylogenic reconstructions also support a morphologically identified sister relationship between S. liparidis and S. thulini and demonstrate a close relationship of S. occidentalipacificus sp. nov. with S. blackeri and S. pritchardae. The analysis of the nd1 gene sequences also confirmed the phylogenetic affinity of S. liparidis to S. thulini. [ABSTRACT FROM AUTHOR]

After a morphological analysis of several tarantula specimens of the genus Eupalaestrus, including recently collected specimens from previously unrecorded localities, we herein describe two new species. They differ from congeners by the presence of a large area with spiniform setae between the coxae IV. They differ from each other in general size and in the thickening of the tibia and metatarsus IV. Eupalaestruscrassimetatarsis sp. nov. is distributed in the Brazilian States of Paraná, Rio Grande do Sul and Santa Catarina, and in Misiones Province in Argentina. Eupalaestrus roccoi sp. nov. is distributed in the Brazilian state of Rio Grande do Sul. These natural grasslands are under threat from rapidly encroaching arable and livestock farming. [ABSTRACT FROM AUTHOR]

The Greater Lizardfish, Saurida tumbil, forms a significant fishery in the demersal trawls along the west coast of India. But, the information regarding the stock structure of this species is scarce. In the present study, the morphology of fish, otolith shape, meristic traits and mt-DNA D-loop region were used to delineate the stocks collected from the west coast of India. Samples were collected between October to November 2018 from three major fish landing centres namely Mumbai, Mormugao and Kochi. Truss network analysis and otolith shape indices revealed the morphological divergence for body and otolith shape among the sampling regions. However, meristic traits and D-loop sequences of mitochondrial DNA could not show variation among the stocks, suggesting the existence of a single panmictic population of S. tumbil. The results of the present study are useful to formulate the stock-specific management measures for S. tumbil along the west coast of India. [ABSTRACT FROM AUTHOR]

The modern sperm whales Kogia and Physeter (superfamily Physeteroidea) represent highly disparate, relict members of a group of odontocetes that peaked in diversity during the middle to late Miocene. Based on a highly informative specimen (including the cranium with ear bones, mandibles, teeth and some postcranial elements) from the lower Miocene (early Burdigalian, 19–18 Ma) of the Chilcatay Formation (Pisco Basin, Peru), we describe here a new genus and species of physeteroid, Rhaphicetus valenciae gen. et sp. nov. The latter is one of the geologically oldest physeteroids. This medium-sized species (estimated body length between 4.7 and 5.7 m) differs from all other physeteroids by the following, probably autapomorphic, features: a narrow, cylindrical rostrum comprising nearly 75% of the condylobasal length; the two main dorsal infraorbital foramina located posterior to the antorbital notch; an upper tooth count of at least 36 teeth per quadrant; and anterior-most upper alveoli filled by thick bony pads. Our phylogenetic analysis recovers R. valenciae as one of the earliest branching stem physeteroids. The highly unusual filling of the anterior upper alveoli by bony pads is interpreted as part of a mechanism leading to the loss of apical and subapical upper teeth. By comparison with other odontocetes displaying some degree of anterior reduction of the dentition, this condition may have corresponded to the rostrum being anteriorly longer than the mandible. The elongated rostrum with a circular cross-section, the long temporal fossa, and the high number of slender, pointed upper and lower teeth all suggest that R. valenciae used its dentition to grasp relatively small prey, possibly via rapid movements of the head. On the one hand, this new Peruvian record increases our knowledge of the morphological disparity of sperm whales during the Miocene. On the other hand, it may provide clues to the ancestral morphotype for all physeteroids. [ABSTRACT FROM AUTHOR]

Brucethoa bharata gen. et sp. nov. is described from the host fish Glossanodon macrocephalus Bineesh and Endo, 2019 (Argentinidae), at depths of 300–600 metres from the south-west coast of India. This monotypic genus is characterised by a head weakly immersed in pereonite 1, dorsum strongly vaulted, pereonites 6 and 7 with posterolateral margin expanded and coxae not visible in dorsal view, relatively wide pleon, pleonite ventrolateral margins produced with lateral gaps evident, both antennae slender, with antennula slightly longer than antenna, and large pleopod rami that extend laterally well beyond the pleotelson margins. Ovigerous females were found in the branchial cavity of the hosts and have proximally thickened oostegites with the posterior marsupium partly enclosed by two sub-rectangular fleshy lobes. All life stages of the new species are described [including females (ovigerous and non-ovigerous), male, transitional and larvae (premanca and manca)]. The species is currently known only from the type locality and the type host. A revised key to the marine branchial cymothoid genera of the world is provided. Publication LSID: lsid: [ABSTRACT FROM AUTHOR]

Tardigrada are a phylum of cosmopolitan invertebrates inhabiting both terrestrial and marine ecosystems. The carnivorous species are usually characterized by a wide buccal tube, which constitutes the first and rigid part of the digestive system. Among tardigrades, only the genus Milnesium is considered exclusively carnivorous and includes the largest known species in the phylum. Some members of the genus exhibit developmental variability in taxonomically important morphological traits such as the number of points on the secondary branches of claws and cuticular sculpturing. Milnesium eurystomum is one of the largest tardigrades, with body length reaching 1.2 mm, and it is equipped with an exceptionally wide buccal tube, enabling this animal to feed on various prey, including other tardigrade species. Importantly, M. eurystomum, as well as other species with wide buccal tubes, were described solely using mature females, thus their developmental variability remains unknown. Interestingly, small Milnesium specimens with remarkably wide buccal tubes have never been reported, raising a question of whether such hatchlings and juveniles (first and second life stages) are extremely rare and simply have never been reported, or their buccal apparatus morphology is different from adults and thus constitutes as an undescribed buccal tube developmental variability. To answer this question, we analysed four populations of M. eurystomum originating from Greenland, Svalbard and Scotland. Due to discrepancies in species delineation based on different types of data, we parallelly applied various methods of species delimitation, both morphological and molecular. Thanks to ontogenetic analysis, we show and describe a novel type of developmental variability in the size and shape of the buccal tube. We also provide novel morphological traits and data for this species, together with the first record and characterization of males. Finally, we discuss the consequences of our findings for the taxonomy of Milnesium and tardigrades in general. [ABSTRACT FROM AUTHOR]

A new ichthyodectiform fish, Amakusaichthys goshouraensis gen. et sp. nov. is described based on several specimens from the Late Cretaceous (Santonian) Hinoshima Formation of the Himenoura Group at Goshoura, Amakusa, Kumamoto in Kyushu, Japan. Amakusaichthys is hypothesized to form a clade with the genus Heckelichthys from the North Atlantic and western Tethyan regions. This new species is highly distinct from other ichthyodectiforms in having the long snout and small mouth with fine conical teeth, which indicates this group had greater diversity than it had been thought. [ABSTRACT FROM AUTHOR]

Assessment of fish trophic ecology in natural environments is imperative to understand biological and ecological requirements, supporting the management and conservation of populations and environments. There are several methods available to assess fish diets, generically divided in noninvasive approaches, such as underwater observations, and invasive approaches, such as analyses of lipid biomarkers, stable isotopes and stomach contents. Each one has application assumptions and conditions that must be aligned with study objectives and methodological criteria, assuring results robustness and allowing comparability among different studies. This review addresses the advantages and limitations of these methods, highlighting those applied for stomach analysis (SA). This work presents complete updated review concerning qualitative and quantitative methods applied to SA: sixty equations were reviewed comprising four formulae to value stomachs per se and, for stomach content analysis, eight single indices, fifteen composite indices and thirty-three equations related to modeling approaches. The review presents different potentialities associated to these methods, standardizes distinct names applied to a same method, and provides clarifications on confusion sources due to the use of same names in distinct methods, a source of scientific mistakes detected in the specialized literature. [ABSTRACT FROM AUTHOR]

Chondrichthyan egg cases are important elements for species-specific identification and also provide a valuable aid in determining a species spatial distribution, as well as for defining spawning areas. Considering the absence of a general key for the identification of the egg cases of the Mediterranean Chondrichthyes, this work aims to fill this gap by presenting a species-specific key based on morphological features of the egg case. The key was developed primarily analysing fresh egg cases dissected from the oviduct, egg cases collected from the seabed or found dried lying on the seashore, after species confirmation by DNA analysis. Original data were integrated with information scrutinized from literature. In order to improve species identification, a protocol for the standardized acquisition of morpho-biometric and meristic features is also provided as a pre-requisite for the appropriate use of the identification key. The total width and length included the horns, when they are not broken, are the parameters that best explain the assignment of the egg case to a specific species. [ABSTRACT FROM AUTHOR]

The red stumpnose Chrysoblephus gibbiceps (Sparidae) is a South African endemic seabream that has been severely depleted by fishing. A total of 678 C. gibbiceps were sampled by line and trawl fishing for a study of their morphology, age, growth, reproduction and diet. In addition, catch records from three time-periods since 1897 were interrogated for distribution patterns and movement behaviour. The sex ratio was 1.5:1 in favour of males. The length–weight relationship, W = 9.32 × 10−5LF2.811, indicates hypoallometric growth. The bulbous head of large males is a secondary sexual characteristic. A von Bertalanffy growth model was fitted to age data obtained using otolith analyses: LF = 429.9 × (1 – e−0.113(t – (−3.799)). The maximum recorded age was 48 years, which is among the highest in seabreams, though the species matures after only 3 years. The gonadosomatic index (GSI) of ripe females (4.5%) was comparatively low, and the two-month-long early-summer spawning season was short compared with that of other sympatric seabreams. The very low GSI of ripe males (1.6%) suggests courtship battles and polygamy. The species feeds over low-profile reefs and consolidated sediments. The principal prey are ophiuroids. Although its trophic level is 3.7, C. gibbiceps has a low-nutrition diet. Historical and current catch data confirm a distribution from Cape Point (southeastern Atlantic) to southern KwaZulu-Natal Province (western Indian Ocean). There is evidence for localised migratory patterns, now partly lost due to severe population depletion. Whereas protogyny and resident behaviour have been suggested as traits that render seabreams vulnerable to fishing pressure, C. gibbiceps is a shoaling gonochorist that has collapsed due to fishing. [ABSTRACT FROM AUTHOR]

Spatial variability in phenotypic characteristics within a fish population may be used to infer the existence of multiple stocks, and knowledge of the population structure of exploited species is important for their sustainable management. In this study we investigated geographic variability in meristic (vertebral count) and morphometric (body shape) characteristics of sardine Sardinops sagax from three southern African regions: Namibia, the South African west coast, and the South African south coast. There were significant regional differences in vertebral counts, with Namibian fish tending to have more vertebrae than South African fish, but with no difference between sardine off the South African west and south coasts. Body shape was characterised using morphometric landmarks, and shape changes were investigated using geometric morphometrics, with influences on fish shape assessed using multivariate regressions. To remove the effects of allometry, the 22 shape variables (represented by Procrustes coordinates) were regressed against fish size (represented by centroid size). There was a significant allometric effect, which was removed by using the residuals of these regressions in further analyses. A multivariate multiple regression was applied to the 22 size-corrected shape variables and to three covariates: condition factor, stomach fullness and fat stage. The significant influence of these covariates was removed by using the residuals from this regression in a canonical variate analysis, where corrected shape variables were classified in relation to region, year and sex. The Mahalanobis distances from the canonical variate analysis differed significantly for most combinations of classifier variables, with clear separations among the three regions. Sardinops sagax off Namibia had thicker bodies and more contracted tail regions than South African fish, whereas S. sagax off the South African south coast had thinner bodies and smaller heads than those off the west coast. These results support the hypothesis of multiple sardine stocks around southern Africa. [ABSTRACT FROM AUTHOR]

Two new species of calliotropid gastropods, Calliotropis (Riselloidea) faustiankensis sp. nov. and Calliotropis (Riselloidea) lukovensis sp. nov., are described from the Middle Jurassic (Middle Bathonian−Upper Callovian) of Poland. Additionally, new excellently preserved shells of Calliotropis (Riselloidea) biarmata (Münster) allow redefinition of this species. The new morphological information obtained from these three fossil species of Calliotropis in combination with the dataset assembled from 20 extinct and 24 living calliotropids is here summarized in quantitative multivariate and principal component analyses suggesting an onshore-offshore trend in calliotropid gastropod evolution from the Triassic to Recent times. This trend, which is expressed in the morphology of shells, shows that the Mesozoic species are mostly shallow water, while Cenozoic and Recent taxa are mostly deep water. The distinction supports earlier suggestions that the genus Calliotropis can be subdivided into two temporal subgenera belonging to the family Eucyclidae Koken. http://zoobank.org/urn:lsid:zoobank.org:pub:C8362FB8-966A-4322-95D5-7151CED20476 [ABSTRACT FROM AUTHOR]

Artemesia longinaris was analyzed here with respect to reproductive period, recruitment and sexual maturity. Samples were carried out in five transects, monthly, from November 2008 to October 2009, at Fortaleza Bay, north coast of the State of São Paulo, in Brazil, in a region recently decreed as a Marine Protected Area. In total, 1173 individuals were captured: 198 juveniles, 97 rudimentary females, 485 breeding females and 409 adult males. Breeding females and juveniles appeared seasonally and their abundances were positively corelated with bottom water salinity and temperature. The female size at the onset of sexual maturity was estimated as 13.29 mm of carapace length. Our results indicated that Fortaleza Bay can be considered an appropriate place for the reproduction of A. longinaris during summer, because the environmental conditions there in this period are favourable. We suggest that the fishing ban period should be adequate to take into account the reproductive behaviour of other shrimp species, such as A. longinaris, since it is currently based only on the recruitment of species of Farfantepenaeus. [ABSTRACT FROM AUTHOR]

The prawns Macrobrachium amazonicum and Macrobrachium jelskii, have been introduced in the southeastern Brazilian region. Thus, it becomes necessary knowing the reproductive aspects of these invasive species. This study aimed to analyze the relative growth and to estimate the morphological sexual maturity of the freshwater prawn species M. amazonicum and M. jelskii. We collected monthly samples from January through December 2010 in th Rio Grande riverbank. Prawns were measured to their cephalothorax length (CL), length of the pleura of the second abdominal somite in females (PL) and length of the appendix masculina (AML). We analyzed 2937 specimens of M. amazonicum (628 males and 2,309 females) and 2167 specimens of M. jelskii (504 males and 1663 females). We observed different allometric patterns in the relative growth of the AML and PL (both more accentuated in M. amazonicum) between the species. The present results indicate that these species adopt different reproductive strategies, possibly representing adaptations that may have facilitate their establishment in the Rio Grande riverbank. When comparing our results to the ones obtained in previous studies, we observed that the reproductive traits of both species indicate a marked phenotypic plasticity. [ABSTRACT FROM AUTHOR]

Selection on morphological traits can vary across the range of species, inducing a mosaic of phenotypes across populations. Intraspecific morphological divergence had been demonstrated for many fish groups inhabiting environments with varying abiotic or biotic selective pressures. Such intraspecific phenotypic variation can have a strong influence on the ecologies of species. In the current study, we examined patterns of intraspecific morphological divergence between two populations of Sarotherodon melanotheron and Coptodon guineensis in Lake Ahémé and Porto-Novo lagoon, Benin. Using multiple morphological traits, we demonstrated intraspecific morphological divergence between Lake Ahémé and Porto-Novo lagoon for these species. However, evidence for parallel divergence was found for these two species, implying a similar response to selective pressures might have been acting on labile traits. In addition, species specific morphological changes observed in the current study might be because of differing responses to similar selective forces or taxon-specific selective forces acting on labile traits. The intraspecific trait divergence demonstrated in the current study suggests several possible selective pressures acting on these populations, yet the cause of this divergence remains unknown and additional studies are required to test these inferences. [ABSTRACT FROM AUTHOR]

Current literature states that family Scombropidae consists of a single genus Scombrops comprising three species worldwide, with two of them, Scombrops boops and Scombrops gilberti, distributed in the waters around the Japanese Archipelago. Although these two scombropids are commercially important species, little is known about the ecology of these fishes. It is difficult to discriminate between these two species based on external characteristics because of their morphological similarity. Here, we report two different morphotypes characterized by the relative growth between the otolith size and the standard length (SL) of the scombropid specimens caught in southern waters off Kyushu Island, Japan, and show the genetic relationship between the morphotypes by means of phylogenetic analyses using complete DNA sequences of the cytochrome b gene. The relationship between otolith weight and SL was significantly different between specimens<505mm SL and those>550mm SL. Phylogenetic analysis demonstrated that the sequences from these scombropid specimens formed three clades: two corresponded to S. boops and S. gilberti, while the third did not correspond to any sequence recorded in databases, suggesting that these specimens are undescribed scombropid species. Almost all the specimens with SL<505mm (n=76) were identified as S. boops, and only nine as S. gilberti. On the other hand, almost all the specimens with SL>550mm (n=41) fell in the unidentified group except for four specimens, whose sequences were identical to that of S. boops. [ABSTRACT FROM AUTHOR]

Ngangtse Co (4535 m a.s.l., 840 km2) is a typical endorheic lake in Tibet. In 2015, we investigated the fish resource in this lake and its rivers and collected two Triplophysa species, including T. brevicauda and T. stewarti. To understand the evolutionary dynamics of Triplophysa in Ngangtse Co, the adaptive and genetic divergence between river and lake populations were investigated by analysing their morphological characteristics and mitochondrial COI and Cytb sequences. Among all of 277 samples, the ratios of the number of T. brevicauda to T. stewarti were 27:8, 34:11, 14:24, 37:0, 16:23 and 0:83 in river populations RA, RB, RC, RD, lakeside population LSE and lake population L, respectively. For T. brevicauda, a small but significant genetic divergence (mean FST = 0.0890) was detected between population RD and other three river populations, and significant morphological differences of body length/body height and body length/caudal peduncle length were observed between population RD and RA, RB, suggesting an association between differentiation and geographical distance. For T. stewarti, very high levels of genetic differentiation was observed between population L and other populations with the FST values ranging from 0.4737 (L-RA) to 0.7074 (L-RC). In addition, significant differences of most of morphological characteristics were observed between the lake (L) and river (RC) populations, indicating that lake fish of T. stewarti was a population that showed a long-term adaptation to the saltwater lake. These results provide insights on the evolutionary dynamics of Triplophysa in Ngangtse Co and help us to understand the fish speciation in endorheic lakes on the Qinghai-Tibetan Plateau. [ABSTRACT FROM AUTHOR]

The effects of cadmium concentration (0, 2.5 and 5 mg L−1) on melanocyte-stimulating hormone (MSH), melanophore index (MI), and melanophore number (MN), as well as a microscopic examination of scale melanocytes in tilapia (Oreochromis niloticus Linnaeus, 1757) was evaluated at different salinity levels (0, 5 and 15 ppt). The levels of MSH, MI, and MN were lower in Cd-exposed fish than in control fish (not exposed to Cd) at salinity level of 0 and 5 ppt. In ppt, however these levels of MSH, MI and MN in control and Cd-exposed fish were not significantly different. In the media without Cd, the levels of MSH, MI and MN were not significantly different at all salinities. The morphological changes of melanophores were higher in Cd-exposed fish than in control fish at salinity 0 and 5 ppt, respectively. These morphological changes were not significantly different in the control fish at all salinities as well as in fish exposed to 0-5 mg L−1 Cd at salinity of 15 ppt. This study therefore demonstrates that the toxic effect of Cd on MSH levels and melanophore morphology decreased with increasing salinity. Further, due to the sensitivity of chromatophores to Cd, melanophore morphology is proposed as a biomarker of Cd exposure in aquatic ecosystems. [ABSTRACT FROM AUTHOR]

The aim of this study was to demonstrate that fish larvae identified using their COI sequences offer a unique opportunity for improving the knowledge of local fish richness. Fish larvae were sampled at the end of their pelagic phase using light-traps set off the West Coast of La Reunion Island, southwestern Indian Ocean, once per month from October 2014 to March 2015. Among the 5174 larvae caught, 214 morphologically different specimens were selected, 196 successfully barcoded, giving a total of 101 different Barcode Index Numbers (BINs). Among these BINs, 55 had never been recorded in La Reunion exclusive economic zone (EEZ), and 13 were new for the BOLD database. Even if the sampling effort for collecting fish post-larvae during this study was relatively low, it allowed adding at least nine new species to an updated checklist of fishes of La Reunion EEZ. [ABSTRACT FROM AUTHOR]

Four species of the genus Osteobrama collected from five different sampling sites of Chindwin and Barak river basin of North-East India, namely O. belangeri, O. cotio, O. cunma and O. feae, were characterized. Meristic study showed differences in anal fin rays count and lateral line scales. Morphometric analysis revealed significant differences among Osteobrama species. In Truss analysis, a clear pattern of differentiation was observed among the four species with discriminant function analysis assigning 100% correctly to the particular species. In molecular analysis, four Osteobrama species collected were barcoded with COI and 16S rRNA sequences and phylogenetically these four species formed two distinct clusters, O. belangeri form one separate cluster, from the other three species i.e. O. cotio, O. cunma and O. feae. High-resolution clusters generated (NJ trees) aided the groupings of species corresponding to their genera and families which are in confirmation to the values generated by COI Automatic Barcode Gap Discovery bioinformatics platform. [ABSTRACT FROM AUTHOR]

The objectives of this study were to investigate the digestibility of pumpkin seed cake (PSC) for the rainbow trout, Oncorhynchus mykiss (Walbaum, 1792), and effects on performance and product quality traits of four different fish species when PSC partially replaced fishmeal in extruded diets. A digestibility trial was carried out to determine apparent digestibility coefficients (ADC) for crude protein (CP), ether extract (EE) and gross energy (GE) of PSC fed to rainbow trout. In subsequent growth trials, effects on performance and morphological traits and fillet colour values of four different fish species [rainbow trout; brook trout, Salvelinus fontinalis (Mitchill, 1814); African sharptooth catfish, Clarias gariepinus (Burchell, 1822); and wels catfish, Silurus glanis (Linnaeus, 1758)] were evaluated when 60% of fishmeal protein of a reference diet was replaced by PSC protein (based on digestible CP). Nutrient ADC of PSC were high (CP: 89%, EE: 88% and GE: 84%). No significant effects on growth and only minor effects on fillet colour were detected in the trials. However, replacing fishmeal with PSC at the chosen level affected morphological traits and feed conversion in all four species to different extents. Replacement effects of PSC should be tested at lower levels of inclusion before conclusions are drawn on its suitability in fish diets. [ABSTRACT FROM AUTHOR]

The species-rich genusMustelus(smoothhounds) of the shark family Triakidae is one of the most bio-economically important groups of elasmobranchs in the world’s oceans. Despite the commercial value ofMustelus, the systematics of the group remains largely unresolved and there is no global review or synthesis of knowledge about the conservation status and conservation genetics of smoothhounds across all oceanic regions. Here, we analysed published studies as well as grey literature to gain insight into the biogeographic, ecological and behavioural factors that shape genetic diversity in smoothhounds, and we identify critical knowledge gaps. From a series of molecular phylogenetic studies it can be inferred that the genusMustelusis paraphyletic and that the aplacental species evolved secondarily from the placental species of the genus. The increasing availability of genetic data aids in disentangling systematic issues, such that more meaningful morphological characters can be chosen for use in practical field-identification keys for co-occurring smoothhounds. An integrative taxonomic approach to the genusMustelusmay offer the best chance of recording and protecting the biodiversity of these sharks. Furthermore, it is evident that different smoothhound species exhibit unique gene-flow patterns, suggesting varying rates within species and hence that species-level conservation approaches would be most appropriate. Molecular studies have advanced our understanding of smoothhound biology (including reproductive traits), ecology and evolution. While many knowledge gaps remain, a crucial lesson from this review is that, when doing assessments on a molecular level, it is important to place genetic results in a broader context, by assimilating biological and ecological data, if definitive conclusions are to be drawn. [ABSTRACT FROM PUBLISHER]

The reaction field of juvenile false percula clownfish (Amphiprion ocellaris) were studied when fed two different developmental stages (nauplii and adults) of the calanoid copepodPseudodiaptomus annandalei. As the copepods undergo ontogenetic development, their morphologic and kinematic traits changes and may therefore influence the ability of the clownfish to identify and capture prey. The fish reacted to nauplii at shorter distances (15.2 ± 7.1 mm) compared to adult copepods (28.0 ± 9.8 mm). However, the fish reaction angle was significantly wider when offered nauplii (−25.3° to 64.4°) compared to adult copepods (−14.2° to 36.7°). This resulted in an equivalent attack rate on both prey items. Hence, even though nauplii are less apparent at greater distances, the fish counteract this partly by reacting to smaller prey items at a wider range. However, the carbon-specific ingestion rate was higher when offered adult copepods, which suggests adult copepods are a more rewarding prey. [ABSTRACT FROM AUTHOR]

Billfishes are important fishery resources traded and consumed worldwide. As morphological traits are usually removed during processing, molecular methods are applied to identify billfish products. In this study, the approaches of quantitative real-time PCR were developed to identify the six billfish species (Istiompax indica,Istiophorus platypterus,Kajikia audax,Makaira nigricans,Tetrapturus angustirostrisandXiphias gladius) widely distributed in the north-western Pacific Ocean. The developed singleplex systems showed high fidelities to each of the six species via either examining the ΔCt values or melting curve patterns. For samples containing multiple species, individual species are identifiable by a quantitative real-time PCR assay that includes all the singleplex systems. A multiplex system was also developed to identify unknown samples composed of a single species. The methods developed in this study provide a fast and high-throughput manner to identify the north-western Pacific billfish species when morphological traits are unavailable, such as in processed products. [ABSTRACT FROM AUTHOR]

The establishment of appropriate taxonomic designations is essential for the effective management of fishery resources. Despite over a century of explorations and research, the cyprinid genus Tor represents a group of large-bodied freshwater fishes whose taxonomy and systematics remains poorly known. While five species of Tor are currently listed as "endangered" on the IUCN Red List, a further five out of 18 species currently recognized are assessed as "data deficient," with at least one undescribed species, believed to be on the brink of extinction (i.e., the Humpback Mahseer endemic to the Cauvery River in India). Tor mahseers represent a suitable model for the application of an integrated approach using morphology, genetics, and historical records to resolve species identities, where one or more of these fundamental approaches may have been deficient in the past. Focusing specifically on the taxonomy and nomenclature of the Tor species recorded from Peninsular Malaysia, one of the aims of this review is to define the identity of two nominal species, T. tambra and T. tambroides. Original descriptions of these two nominal species contain little or practically no characters to distinguish them, and partly explains why secondary literature fails to conclusively determine species boundaries. A phylogenetic analysis of mahseer specimens from this region, based on publicly available and newly sequenced mitochondrial COX1 genes, does not support species designation based on previously established morphological features. More importantly, multiple tree-based species delimitation approaches showed that previously sequenced T. tambroides from Peninsular Malaysia and the newly described Tor species from Vietnam could not be delimited from the topotypic Tor tambra. A wider investigation of mahseer taxonomy covering all of Southeast Asia, using such an integrated approach is recommended to resolve the ambiguous taxonomy and is of profound importance for the conservation and management of exploited and farmed populations of these highly valued and iconic fish. [ABSTRACT FROM AUTHOR]

Ostracoderms are a paraphyletic group of extinct jawless fishes comprising the gnathostome stem and are fundamental to our understanding of early vertebrate evolution. However, only a handful of these clades have robust phylogenies in place, hindering our interpretation of early vertebrate histories. A new phylogeny is proposed for the Pteraspidiformes – the largest and most-studied clade of heterostracan ostracoderms. Difficulties such as large amounts of missing data and the limited morphological variability within the group have led us to explore different coding strategies such as the inclusion of quantitative data and implied weighting. We present a new comprehensive data set including all described genera of Pteraspidiformes (47 taxa) analysed using discrete characters only, a combination of discrete and continuous characters, and gap-coding strategies (transforming the continuous into discrete characters), along with a Bayesian analysis. Two representatives of the Psammosteidae (DrepanaspisandPsammosteus) are also incorporated within the analysis to elucidate their inclusiveness within the Pteraspidiformes. Well-resolved trees are only achieved under re-weighted (implied weighting) analyses. Here, we show that many ‘classic’ Pteraspidiformes clades hold true under our different coding methods, with the implied weighting of discrete characters and inclusion of continuous characters giving very similar topologies. In all instances, the Psammosteidae are found to belong within the Pteraspidiformes, nested with the Spitsbergen generaDoryaspis,XylaspisandWoodfjordaspis. Gap coding, however, results in a different tree topology to other analyses, perhaps due to the high sensitivity to missing data. Our results indicate that careful consideration and justifications should be applied to quantitative characters when reconstructing relationships of homoplastic ostracoderms. Superfamily Doryaspidae superfam. nov. is introduced. http://zoobank.org/urn:lsid:zoobank.org:pub:BF5255A1-1417-432B-AC64-BF132A0BCC65 [ABSTRACT FROM PUBLISHER]

Background: The vertebrate inner ear comprises mineralized elements, namely the otoliths (fishes) or the otoconia (mammals). These elements serve vestibular and auditory functions. The formation of otoconia and otoliths is described as a stepwise process, and in fish, it is generally divided into an aggregation of the otolith primordia from precursor particles and then a growth process that continues throughout life.Results: This study was undertaken to investigate the complex transition between these two steps. Therefore, we investigated the developmental profiles of several inner ear structural and calcium-binding proteins during the complete embryonic and larval development of the cichlid fishOreochromis mossambicusin parallel with the morphology of inner ear and especially otoliths. We show that the formation of otoliths is a highly regulated temporal and spatial process which takes place throughout embryonic and larval development.Conclusions: Based on our data we defined eight phases of otolith differentiation from the primordia to the mature otolith. [ABSTRACT FROM PUBLISHER]

Movement of organisms is an important activity that has ecological and evolutionary implications, including individual reproductive success and survival, population growth and persistence, local adaptation, and gene flow. Expression of movement behavior has traditionally been termed dispersal and measured relative to home ranges. This simplistic approach belies the complexity of the process. Movement of freshwater stream fish has been at times viewed as predominantly restricted in nature, but recent research challenges this paradigm since some distribution of movement exists in every population. A better research approach is to understand the drivers that promote or limit movement. Drivers of movement can be categorized as extrinsic ecological factors (context dependent), e.g., habitat quality, habitat variability, and the presence of predators, and intrinsic traits of the fish (condition dependent), such as body size and condition. One intrinsic trait that has received relatively little attention is the inherent personality to be sedentary or mobile, and how this interacts with the suite of traits and behaviors to drive movement. Future movement behavior research should focus on the interaction of extrinsic and intrinsic drivers to better understand the evolutionary and ecological implications of movement. [ABSTRACT FROM AUTHOR]

There is a significant taxonomic ambiguity among snow trout species due to their morphometric similarities. In view of this, a morphometric and molecular study was conducted on five different species of genusSchizothoraxthat have been reported from Kashmir valley. Morphometric data analyzed using multivariate statistics (Principal component analysis and cluster analysis) indicated the significant grouping of species to individual clusters. Mitochondrial DNA cytochrome oxidase I (COI) gene analysis revealed 0.2%–4.5% genetic divergence among the five species. This study confirms that utility of cytochrome oxidase I in species delineation along with morphometric data. Phylogenetic tree obtained using Neighbor-Joining method revealed that all the five species represented distinct species group. TheSchizothoraxgenus formed two distinct clades; one containingS. niger, S. curvifronsandS. plagiostomus,while other clade containingS. esocinusandS. labiatus. This phlogeny trend was also supported by cluster analysis of morphometric characters. The phylogenetic analysis with other published COI sequences revealed distinct nature of these five species. The study may aid in the taxonomic identification of snow trout species in India. This may further increase the knowledge of the ichthyologists in planning conservation and management strategies for these important fish species along with their natural habitat. [ABSTRACT FROM AUTHOR]

Tilapia (Oreochromis mossambicus) was first introduced to the Philippines in 1950 for aquaculture. Since then, other species of tilapia have been introduced to the country and some of them (mainlyOreochromis niloticus) have become established in lakes and other water bodies. In this study, DNA barcoding using the mitochondrial cytochromecoxidase subunit I (COI) gene was done to assess the reliability of morphological identification and the degree of introgression among feral tilapias (Oreochromisspp.) in seven major Philippine lakes, namely Laguna de Bay, Lake Lanao, Taal Lake, Lake Mainit, Lake Naujan, Lake Bato, and Lake Buhi. Specimens were also collected from a private hatchery in Sual, Pangasinan to serve as reference. Morphological traits, Nucleotide BLAST (BLASTn), and Translated BLAST (BLASTx) analyses were used to classify the specimens. A Neighbor-Joining tree was constructed using the Kimura 2-Parameter method, incorporating 66 COI sequences generated from the study and 20 additional reference sequences obtained from GenBank. ThreeOreochromisclusters were obtained and were classified as theO. niloticusgroup, O. mossambicusgroup, andO. aureusgroup, with bootstrap support values of 99%, 74%, and 99%, respectively. The mean K2P genetic distances within each group were 0.008%, 0.959%, and 0.086%, respectively. The clustering of COI sequences generated from this study corresponded with the results of the BLASTn analysis.Oreochromishybrids were also found in all the lakes. The study highlights the usefulness of DNA barcoding for molecular identification and detection of introgressed individuals, with potential applications in management of feral stocks. [ABSTRACT FROM AUTHOR]

Marthasterias glacialisare found in the cool-temperate waters of the north-eastern Atlantic Ocean, in the subtropical waters of the Mediterranean Sea and along the south-western tip of Africa. The South AfricanMarthasteriaspopulation includes two morphotypes, a smooth, spinelessrarispinaform and a spinyafricanaform, that have been described as separate species, subspecies, orformaby various authors over the past century. To test whether these two morphotypes represent separate species, and whether either, or both, are conspecific with the North-East Atlantic species, 78Marthasteriaswere collected from the Cape Peninsula of South Africa. Morphological comparisons between individuals of the two forms showed no significant clustering of samples, indicating that there is no morphological separation of the two South African forms into distinct groupings. Theafricanaandrarispinaforms were also shown to be genetically indistinguishable, using a fragment of the mitochondrial cytochromecoxidase subunit I (COI) gene and the nuclear internal transcribed spacer 1 (ITS1). In addition, the COI sequences were also compared to those from European specimens, and phylogenetic reconstruction and intra- and interspecific levels of divergence suggested that the South African specimens form a single group that is genetically distinct from the EuropeanM. glacialis. Although the allopatric distribution, high genetic divergence (more than 3% for the COI fragment) and morphological differences suggest that the South African form should be raised to species status under the nameMarthasterias africana, further work must assess an independent genetic marker (nuclear) to support raising the COI clade to species level. TrueM. glacialishave a spine-armament pattern of a series of three or more regular spine rows down the length of each arm, whereasM. africanaare either covered in many irregularly spaced spines, or have an extraordinarily bare surface with only two spine rows per arm.Marthasterias africanamay also have an actinal spine simulating the presence of a third inferomarginal spine. This work tentatively resolves the taxonomic dispute, elucidates the separation and amalgamation of the two African forms and suggests a single, uniquely South AfricanMarthasteriasspecies that might be distinct from the north AtlanticM. glacialis, although further analyses to test reproductive isolation between the North-East Atlantic and South African forms are required. [ABSTRACT FROM AUTHOR]

We examined spatial variability in meristic and morphological characteristics of the branchial basket of sardineSardinops sagaxcollected from four geographical regions around the southern African coast, namely Namibia and the South African west, south and east coasts. Our analysis tested the hypothesis of three putative sardine stocks off South Africa, one in each of the three geographical regions. We therefore collected fish data from Namibia to compare with South Africa, because sardine from the two countries are considered to be separate stocks. Morphometric measurements (gill arch length and gill raker spacing) and meristic data (number of gill rakers) were collected from the left side of the first gill arch from a total of 377 sardine, approximately equally divided between the regions. A multivariate general linear model with caudal length as covariate was used to assess differences among fish from the four regions and significant differences were observed, although not always consistently across all fish size classes. Small South Coast sardine had shorter gill arches than small West Coast sardine, but adults had gill arches of similar length, longer than those from Namibia and the East Coast. Small sardine from the South Coast had fewer gill rakers than small sardine from the West Coast, but larger fish had similar numbers of gill rakers, significantly more than sardine from Namibia and the East Coast. Sardine from the West and South coasts had similar gill raker spacings, which were smaller than those of fish from the East Coast and Namibia. Despite spatially and particularly temporally unbalanced sampling, we consider that these differences provide evidence of spatial variation in Benguela sardine phenotype and that it would support the hypothesis of discrete sardine stocks off Namibia and South Africa. The results are consistent with the hypothesis of three sardine stocks within the southern Benguela. [ABSTRACT FROM AUTHOR]

Spotted scatScatophagus argusis a popular aquarium species around the world due to its colorful appearance, hardiness, slow growth, and calm behavior. It has also been admired as a food fish mainly in the South and South-East Asian countries due to its good nutrient quality with high protein content and taste. Considering its importance both as ornamental and food fish, several researchers have studied on different aspects of its morphology, food and feeding habit, reproductive biology, and culture; but to date no consolidated report is available on these aspects. This report seeks to consolidate all available information on its morphology, biology, and culture and explore the scope for future research that will be beneficial for its fishery and trade. Considering the information summed up in the present report, it is evident that ample information is available on morphological characters, food, and feeding habit ofScatophagus arguswithout adequate knowledge on different aspects of its reproductive biology and culture. Further study is needed on these comparatively less explored aspects to support its fishery and trade in the near future. [ABSTRACT FROM PUBLISHER]

The water holding capacity (WHC) and relationship between protein denaturation and WHC of sea bass skeletal muscle (SBSM) with high pressure (HP) treatment were investigated up to a pressure level of 600 MPa. The results showed that it had the lowest cooking loss (CL) at 200 MPa, and CL value decreased 20.9% compared with 0.1 MPa. Additionally, 400 MPa produced the highest water retention, and 0.1 MPa produced the lowest water retention by low field-nuclear magnetic resonance (LF-NMR). The WHC was related to protein denaturation. Examination of extracted proteins using sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and protein solubility indicated that high pressure resulted in protein denaturation; the differential scanning calorimetry (DSC) curve showed the myosin peak reduced significantly at 400 MPa and was eliminated at 600 MPa, while the actin peak was eliminated at 300 MPa; morphology of sarcoplasmic proteins were sponge-like at 200 MPa, which was conducive to enhancing WHC. [ABSTRACT FROM PUBLISHER]

Stomach content analyses and measurements of gillraker morphology were used to assess the diet and feeding ecology of the East Coast redeye round herringEtrumeus wongratanaiand provide data for comparisons with other small pelagic fishes off South Africa. Samples were collected by jigging from a kayak off Scottburgh, KwaZulu-Natal (KZN), over the period July 2013–May 2014. In total, 66 stomachs (containing 4 407 prey items) and 66 gill arches were examined. Stomach content analyses indicated that East Coast redeye round herring, at the time of sampling, fed on large (1 500–2 500 µm) particles, with ∼2 500 µm particles making the greatest contribution to dietary carbon. The species feeds on larger particles than do anchovyEngraulis encrasicolusand sardineSardinops sagax, but on particles of a similar size to those consumed by West Coast redeye round herringEtrumeus whiteheadi. There were significant differences in mean gillraker gaps between East Coast redeye round herring and both sardine and anchovy, but not between East Coast and West Coast redeye round herring. The differences in gillraker gaps between East Coast redeye round herring, sardine and anchovy are indicative of resource partitioning through differential feeding, based on zooplankton size. The data suggest that there is no resource partitioning between East and West coast redeye round herring, indicating that competition is likely to occur between them. However, such competition is minimised by limited spatial overlap between these two species. [ABSTRACT FROM AUTHOR]