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Environmental and genetic variables can exert an influence on alterations in morphological traits. Within fish species inhabiting diverse aquatic settings, there can be observed variations in morphological traits. Genetically, variations in fish morphological characteristics can occur through mating and gene flow. To date, there has been a lack of research conducted on the variability in morphological traits and genetic relationships between Lutjanus timoriensis, L. malabaricus, and L. erythropterus. Thus, the current research aimed to identify variations in the morphological characteristics as well as in the intra- and inter-specific relationships between three red snapper species from the genus Lutjanus. Cytochrome oxidase I (COI) gene was used to study the molecular relationship among species of red snapper. The results showed that L. timoriensis had high intraspecific morphological variation in young individuals. Morphologically, L. timoriensis, L. malabaricus, and L. erythropterus are very similar. Unlike L. malabaricus and L. erythropterus, young and adult L. timoriensis have black patches in the pectoral fin axils. The adult L. erythropterus has a comparatively small mouth, no hump on its head, and no black saddle at the base of its tail. Meanwhile, L. malabaricus has a comparatively large mouth, a head with a hump, and a black saddle at the base of its tail. In terms of body size, L. erythropterus is larger than L. timoriensis and L. malabaricus. Based on NCBI and Bold System data, molecular analyses determined that the observed fish were L. timoriensis, L. malabaricus, L. erythropterus with a similarity of between 99.85 and 100%. The phylogenetic tree construction demonstrated that L. malabaricus, L. timoriensis and L. erythropterus were closely related. [ABSTRACT FROM AUTHOR]

Genetic structure and connectivity information can be used to identify biological corridors and prioritize the conservation of areas that help maintain ecosystem integrity. Some marine fish, especially those of commercial interest, have been proposed as suitable indicators to identify potential marine biological corridors due to their high mobility among habitats and socioeconomic importance. In this study, we assessed the genetic structure of lane snapper populations in the Honduran Caribbean to evaluate connectivity and identify potential environmental barriers. Furthermore, we evaluated the genetic characteristics of the lane snapper on a larger spatial scale, including populations across the rest of its distribution range in the western Atlantic, using mtDNA and nuDNA markers. Our results demonstrate a significant genetic diversity of lane snappers in the Honduran Caribbean. Furthermore, despite their high dispersal potential, we observed genetic structuring in lane snapper populations on a larger spatial scale, resulting in the formation of two distinct groups throughout their distribution range: group 1 from Florida, the Gulf of Mexico, Honduras, and Colombia and group 2 from Puerto Rico and Brazil. This genetic differentiation can be attributed to oceanographic barriers such as river plumes and marine currents. These findings have the potential to significantly impact marine conservation and management efforts in the region, both at local and regional scales. It is anticipated that they will not only inform but also elicit a response, driving further action towards effective conservation measures. At a local scale, we recommend that conservation efforts focus on protecting critical habitats. At a regional scale, lane snappers should be included in the management plans of existing marine protected areas necessary to ensure the long-term sustainability of the species and the marine ecosystems in which it resides. [ABSTRACT FROM AUTHOR]

Deepwater fisheries in the Caribbean Sea are poorly studied and mostly unmanaged, despite their importance to local economies and food security. In the MesoAmerican region, deepwater fisheries are nearshore and easily accessible in many locations by small vessels, but historical and contemporary fishing effort varies by country. We used standardized fishery-independent methods, including vertical longlines and baited remote underwater video (BRUV) to assess the relative abundance and distribution of deepwater (100–550 m) snappers and groupers in Belize and Honduras. Fishery-dependent samples were used to supplement spatial distribution and body length data. Gathered data revealed that Belize, with a smaller fishing population and shorter history of deepwater fishing, had overall higher abundance of groupers and snappers and that fish were significantly larger than those in Honduras, which has a well-established and larger deepwater fishery. Water temperature was found to influence the abundance and occurrence of deepwater snappers more than depth. Deepwater snappers were widely-distributed throughout available habitat in both countries, but groupers were more patchy, and rarely encountered in the more heavily fished areas off Honduras. Our results suggest that a precautionary approach to fisheries management and targeted biological research of these stocks is required, which is particularly relevant for Belize, where climate change and overfishing mitigation measures are focused on an expansion of the deepwater fishery. [ABSTRACT FROM AUTHOR]

Genetic structure and connectivity information can be used to identify biological corridors and prioritize the conservation of areas that help maintain ecosystem integrity. Some marine fish, especially those of commercial interest, have been proposed as suitable indicators to identify potential marine biological corridors due to their high mobility among habitats and socioeconomic importance. In this study, we assessed the genetic structure of lane snapper populations in the Honduran Caribbean to evaluate connectivity and identify potential environmental barriers. Furthermore, we evaluated the genetic characteristics of the lane snapper on a larger spatial scale, including populations across the rest of its distribution range in the western Atlantic, using mtDNA and nuDNA markers. Our results demonstrate a significant genetic diversity of lane snappers in the Honduran Caribbean. Furthermore, despite their high dispersal potential, we observed genetic structuring in lane snapper populations on a larger spatial scale, resulting in the formation of two distinct groups throughout their distribution range: group 1 from Florida, the Gulf of Mexico, Honduras, and Colombia and group 2 from Puerto Rico and Brazil. This genetic differentiation can be attributed to oceanographic barriers such as river plumes and marine currents. These findings have the potential to significantly impact marine conservation and management efforts in the region, both at local and regional scales. It is anticipated that they will not only inform but also elicit a response, driving further action towards effective conservation measures. At a local scale, we recommend that conservation efforts focus on protecting critical habitats. At a regional scale, lane snappers should be included in the management plans of existing marine protected areas necessary to ensure the long-term sustainability of the species and the marine ecosystems in which it resides.

Abstract In this study, we tested the taxonomic validation of red snappers species (Southern red snapper Lutjanus purpureus; Silk snapper L. vivanus; Blackfin snapper L. buccanella; and Pacific red snapper L. peru) based on comparative analysis, using four methods for species delimitation. These methods were based on either genetic similarity or phylogenetic trees inferred from two mitochondrial (Cytochrome b and D-loop) and two nuclear (Myostatin and S7 introns) markers. On one hand, the genetic results corroborated the presence of four red snapper species, confirming their taxonomic validation despite their remarkable morphological similarity. On the other hand, few incongruencies in the species delimitation methods were observed according to the phylogenetic reconstruction method (maximum likelihood or Bayesian inference) when using. Based on the phylogenetic results, L. buccanella should represent a more ancient lineage in relation to the clade that encompasses L. purpureus, L. peru and L. vivanus. The single-locus phylogenetic analysis based on Cytb recovered each the red snapper species as a well-supported clade. Overall, this study provided a DNA-based validation of the traditional morphological taxonomy of red snappers.

To conserve species and determine suitable management plans, the insidious and accurate identification of a species is fundamental. Despite the commercial importance of Lutjanidae family, the phylogeny of Lutjanidae has not been fully studied. Thus, this study focused on the phylogeny of this family using mitochondrial 16S rRNA sequences in four species; Lutjanus fulviflamma, Lutjanus monostigma, Lutjanus bohar and Lutjanus kasmira. The generated bands of 16S rRNA in the four species prolong from 561 to 575 bp. The sequences of 16S rRNA were displayed in GenBank/NCBI to gain the accession numbers (OQ803478.1 - OQ803481.1). The average frequencies of adenine (A), thymine (T), cytosine (C) and guanine (G) were 28.91, 21.93, 25.51 and 23.65%, respectively. [ABSTRACT FROM AUTHOR]

Lutjanus commonly known as snappers are economical fishes in the world, including in Indonesia. They have high morphological similarities and are difficult to distinguish. Therefore, this study aimed to validate the taxonomic status and kinship of four dominant snappers harvested from the northern coastal waters of Aceh, Indonesia, namely Lutjanus bengalensis, Lutjanus kasmira, Lutjanus gibbus , and Lutjanus fulviflamma. The samples were collected from Pulo Aceh and Lampulo fish landings. A total of 60 samples of each species were used for morphometric analysis using the traditional morphometric approach, while five from each of them served as samples for the genetic analysis with the COI gene. Morphological analysis showed that the four fish species were categorized into 3 different groups, where L. bengalensis and L. kasmira were in the same group. The genetic analysis revealed that they were grouped into four different clades, but L. bengalensis and L. kasmira were located in the same sister clade, indicating genetic closeness. L. bengalensis , L. kasmira, L. gibbus, and L. fulviflamma had two, three, three, and four haplotypes, respectively. Based on the results, the COI gene successfully distinguished the four species of snapper, where L. bengalensis and L. kasmira had morphological and genetic similarities. Furthermore, L. fulviflamma had higher genetic diversity than the others. [ABSTRACT FROM AUTHOR]

Postmortem examination of a wild Lutjanus erythropterus exhibiting emaciation associated with multifactorial causes is presented. Skeletal muscle analysis for heavy metals revealed presence of threefold cadmium concentration in comparison with the European standards. Multifocal necrosis and muscle atrophy (condition factor K = 0.92) were also noted. Other anomalies recorded included abdominal distension and bilateral sunken eyes. The liver showed scant vacuolation, melano‐macrophage centres and diffuse granulomatous lesions also occurring in the viscera and mesenteries. Intensity of infection varied from 2 to 9 parasites, while 16S rRNA sequences revealed the opportunistic pathogen Photobacterium damselae complex only in affected organs. This is the first record of non‐aetiologic and aetiologic factors occurring concurrently in a wild fish in Oman. Although no definitive conclusions can be drawn, these findings highlight the urgent need for further fish health assessment regarding these pathologies and other diseases that pose a health risk to other fish species. [ABSTRACT FROM AUTHOR]

The well-cataloged marine fish fauna of the Galapagos Islands includes eight of the 12 species of snappers (Lutjanidae) found in the Tropical Eastern Pacific. A recent recreational scuba dive in the Galapagos produced photographs of an additional snapper species, Lutjanus inermis (Peters, 1869), which was sufficiently common as to likely have a recently established resident population. [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]

Age-based life history parameters: the asymptotic length (L∞), the growth coefficient (K) and the hypothetical age at zero length (t0), for Lutjanus bohar in Jeddah fisheries were estimated. Scales were used for age determination and measurements, and the back-calculated lengths-at-ages were calculated using the body proportional formula (BPH). The growth of L. bohar is isometric where the length-weight relationship could be described by the power equation: W = 0.0125 L3.05 (R² = 0.99) for males, W = 0.01571 L3.00 (R2 = 0.98) for females, and W = 0.0142 L3.04 (R² = 0.99) for combined sexes. The Scale radius (S) total length (L) relationship could be described by the linear form: L = 5.52 S - 0.41 (R² = 0.953) for males, L = 5.64 S - 0.85 (R² = 0.945) for females, and L = 5.60 S - 0.39 (R² = 0.948) for combined sexes. The growth parameters were estimated to be: L∞ = 89.38 cm, K = 0.123 year-1, and to = -1.04 year for males; L∞ = 90.68 cm, K = 0.121 year-1, and to = -1.05 year for females; and L∞ = 90.17 cm, K = 0.122 year-1, and to = -1.04 year for pooled data. The performance index of growth in length ' Ф' ' was found to be 3.0 for both males and females. The maximum age (life span) was estimated to be 23.8 year for females and 22.8 year for males, which indicate that L. bohar is a long-lived species. [ABSTRACT FROM AUTHOR]

The anchor worm Lernaea cyprinacea is a freshwater parasitic copepod with little host specificity, potentially infesting various freshwater fishes and some amphibians. Although its life cycle has been researched well in aquacultural environments to protect breeding fish from the heavy damage it causes, little is known about the ecology of L. cyprinacea in natural waters. In this study, three specimens of L. cyprinacea were obtained from a tropical abortively migrating snapper, Lutjanus argentimaculatus, collected from a small river in Chiba Prefecture in eastern Japan, where the freshwater fish fauna is poor. This occurrence represents a new host record for L. cyprinacea and the first case of it utilizing an abortively migrating fish. This record also suggests that external resources such as abortively migrating fish could contribute to the maintenance of local L. cyprinacea populations in habitats with few freshwater fish. [ABSTRACT FROM AUTHOR]

This study describes the advances in spotted rose snapper Lutjanus guttatus juveniles production. The broodstock (three groups, each of ten females, mean ± SD: 0.91 ± 0.2 kg and 20 males 1.2 ± 0.3 kg) with two years, were acclimated for 1.5 years in three communal cylindrical fiberglass tanks (18-m3). Fertilized eggs were obtained during natural spawning seasons. Floating eggs (average 90 ± 2%) were collected between 12 to 14 h after spawning. An average of 97% of them were transparent with live embryos. For the larval rearing process, initial stocking densities were 196 ± 70 embryos/l, incubated in twelve 6-m3 cylindrical fiberglass tanks with 3-m3 of water. The incubation period was 20 h at 26-28 °C. Hatching and survival at 48-h post-hatch (hph) were 90 ± 2% and 55 ± 10%, respectively, with an average of 281,258± 92,202 48-h larvae per tank and 105 ± 33 larvae/l at first feeding. A total of 338,812 juveniles with 45 days post-hatched (dph) were harvested, at an average of 28,234 ± 11,890 per larval rearing tank (2.4±1.0/l), and 180,000 juveniles (BW: Body weight of 5-8 g) from the nursery tanks with 90 dph. Average survival from first feeding to end of 45 dph rearing period was 12 ± 9%. The average harvest weight was 0.47 ± 0.10 g BW and the average final biomass per larval tank was 13 kg. An efficiency index at 45 days culture was 10 / 48-h larvae/juvenile, while at 90 dph the efficiency index was 19 / 48-h larvae/juvenile. The result showed that changes to the previous culture protocols of the CIAD-Mazatlan fish plant, ensure a higher production of juveniles. [ABSTRACT FROM AUTHOR]

Copyright of Galapagos Research is the property of Charles Darwin Foundation for the Galapagos Islands and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Abstract Human communities living around Cartagena Bay (Colombian Caribbean) depend on fishing activities as their main income and food source. This resource has been affected by pollution, sedimentation and overfishing. DNA barcoding was used for fish species identification, and the genetic diversity and population structure of two valued fish genera, snappers (Lutjanus spp.) and jacks (Caranx spp.) from the main fishing grounds in the area was evaluated. Fishermen collected tissue samples and measured size and weight and capture location for each fish. A 700 base pairs (bp) fragment of the mitochondrial Cytochrome Oxidase I (COI) was sequenced for 104 samples (55 snappers and 49 jacks). Comparisons against Genbank allowed identification of eight species: Lutjanus synagris, L. apodus, L. jocu, L. cyanopterus, L. analis, Caranx hippos, C. latus and C. crysos. Genetic diversity for the fish around the Colombian Caribbean sampling locations was relatively high in comparison to those of other populations and population differentiation was significant for some species, particularly for L. synagris and L. apodus , suggesting that the fish from the Colombian Caribbean belong to an independent stock. Mean body length for all species was significantly smaller than body length at maturity, indicating that all fish captured were immature. Levels of genetic diversity appear to be high in these fish populations. The fact that fishermen are capturing immature fish is worrisome, suggesting the need to improve management of fish populations and the need to include the communities in conservation planning for the Islas del Rosario National Natural Park. Highlights • Communities living around Cartagena Bay rely of fisheries as their main income and food source. • DNA barcoding was used for fish species identification. Genetic diversity and population structure was tested. • Fishermen collected tissue samples and measuring fish size and weight. • Eight species were identified. Genetic diversity around sampling locations was high. • Mean body length for all fish was smaller than body length at maturity. • All fish captured were immature and improved management of fish populations is needed. [ABSTRACT FROM AUTHOR]

Graphical abstract Unlabelled Image Highlights • Dexamethasone induced mstn-1 expression in Lutjanus guttatus skeletal muscle. • Dexamethasone also induced the expression of foxo3b in a late response. • Silencing of mstn-1 reduced the expression of foxo3b and murf1. • Silencing of mstn-1 induced the expression of mtor , myod-2 and myogenin. • Mstn-1 signaling modulates muscle catabolism in the presence of dexamethasone. [ABSTRACT FROM AUTHOR]

Knowledge of marine ecosystems that grow and reside on and around subsea oil and gas infrastructure is required to understand impacts of this offshore industry on the marine environment and inform decommissioning decisions. This study used baited remote underwater stereo-video systems (stereo-BRUVs) to compare species richness, fish abundance and size along 42.3 km of subsea pipeline and in adjacent areas of varying habitats. The pipeline is laid in an onshore-offshore direction enabling surveys to encompass a range of depths from 9 m nearshore out to 140 m depth offshore. Surveys off the pipeline were performed across this depth range and in an array of natural habitats (sand, macroalgae, coral reef) between 1 km and 40 km distance from the pipeline. A total of 14,953 fish were observed comprising 240 species (131 on the pipeline and 225 off-pipeline) and 59 families (39 on the pipeline and 56 off-pipeline) and the length of 8,610 fish were measured. The fish assemblage on and off the pipeline was similar in depths of <80 m. In depths beyond 80 m, the predominant habitat off-pipeline was sand and differences between fish assemblages on and off-pipeline were more pronounced. The pipeline was characterised by higher biomass and abundances of larger-bodied, commercially important species such as: Pristipomoides multidens (goldband snapper), Lutjanus malabaricus (saddletail snapper) and Lutjanus russellii (Moses’ snapper) among others, and possessed a catch value 2–3 times higher per stereo-BRUV deployment than that of fish observed off-pipeline. Adjacent natural seabed habitats possessed higher abundances of Atule mate (yellowtail scad), Nemipterus spp. (threadfin bream) and Terapon jarbua (crescent grunter), species of no or low commercial value. This is the first published study to use stereo-BRUVs to report on the importance of subsea infrastructure to commercially important fishes over a depth gradient and increases our knowledge of the fish assemblage associated with subsea infrastructure off north-west Australia. These results provide a greater understanding of ecological and fisheries implications of decommissioning subsea infrastructure on the north-west shelf, and will help better inform decision-making on the fate of infrastructure at different depths. [ABSTRACT FROM AUTHOR]

Mangrove Red Snapper (Lutjanus argentimaculatus) is a large, palatable fish that has become increasingly valuable for aquaculture in South East Asia. Unfortunately, the bulk of current mariculture of L. argentimaculatus depends almost entirely on fingerlings collected from the wild, since hatchery-raised fry are regarded as inferior by fishermen. Wild Mangrove Red Snapper spawn on offshore reefs, but their larvae occupy coastal lagoons and estuaries. In this study, we examine some of the factors (habitat structure and salinity) associated with the natural recruitment habitat of L. argentimaculatus to determine whether they might play a role in the perceived superiority of wild-caught fry. We found statistically significant relationships between survival and salinity, and between somatic growth and habitat structure, but no interaction between the factors. Juvenile L. argentimaculatus survive best at moderate (17ppt) salinities, with fresher water (10ppt) providing better outcomes than more saline (25ppt) conditions. We found also that juveniles grew best when provided with hard, complex structures (rock piles and mangrove roots), rather than in tanks without such structures. Here, we have demonstrated two simple environmental factors that improve survival and growth of juvenile L. argentimaculatus and may provide a substantial boost to the performance of hatcheryreared fish. [ABSTRACT FROM AUTHOR]

Abstract Three species of snappers from artisanal, small-scale fisheries were examined for the presence of parasites. A total of 139 lutjanid fish were collected: 69 specimens of Lutjanus analis, 47 specimens of Lutjanus vivanus, and 23 specimens of Lutjanus synagris. Encysted plerocercoid of trypanorhynch cestodes found at necropsy in the viscera of snappers were sampled for parasitological analysis. These plerocercoid larvae belong to the genera Floriceps, Pseudogrillotia , and Oncomegas. Although these parasites do not have any zoonotic potential, fish with heavy loads of plerocercoids are rejected during inspection as they compromise meat hygiene. Our findings suggest that light larval cestode infections in lutjanids would not lead to consumer rejection of the food product. The occurrence of Floriceps sp. in L. analis and in L. synagris, of Pseudogrillotia sp. in L. vivanus and in L. synagris , and of Oncomegas sp. in L. synagris are new findings in these fish species. These parasites are new to these fish species and have not been reported in snappers from the northeast coast of Brazil. The results contribute to the existing body of knowledge about the parasitic fauna of fish and its distribution along the coastline of Brazil.

This study provides the first record of Lutjanus xanthopinnis Iwatsuki, Tanaka et Allen, 2015 from the Andaman Islands. The new record is based on 2 specimens, 123 and 154 mm SL, captured inshore of Dignabad, Port Blair, Andaman Islands, India. The fish were examined, described, and illustrated. Morphometric and morphological data confirmed that the specimens examined from the Andamans are L. xanthopinnis, which varies distinctly from a closely-related species Lutjanus madras (Valenciennes, 1831). [ABSTRACT FROM AUTHOR]

Management of wild fisheries resources requires accurate knowledge on which species are being routinely exploited, but it can be hard to identify fishes to species level, especially in speciose fish groups where colour patterns vary with age. Snappers of the genus Lutjanus represent one such group, where fishes can be hard to identify and as a result fisheries statistics fail to capture species-level taxonomic information. This study employs traditional morphological and DNA barcoding approaches to identify adult and juvenile Lutjanus species harvested in Malaysian waters. Our results reveal a suite of species that differs markedly from those that have previously been considered important in the Malaysian wild-capture fishery and show that official fisheries statistics do not relate to exploitation at the species level. Furthermore, DNA barcoding uncovered two divergent groups of bigeye snapper (‘Lutjanus lutjanus’) distributed on either side of the Malay Peninsula, displaying a biogeographical pattern similar to distributions observed for many co-occurring reef-distributed fish groups. One of these bigeye snapper groups almost certainly represents an unrecognized species in need of taxonomic description. The study demonstrates the utility of DNA barcoding in uncovering overlooked diversity and for assessing species catch composition in a complicated but economically important taxonomic group. [ABSTRACT FROM AUTHOR]

Abstract This study has employed an integrated statistical approach to determine the extents to which species richness and abundance (catch rate) of fishes over reefs along an extensive coastline were related to various factors. Fish were thus sampled by trapping over deep (~ 22 m) and shallow (~ 12 m) reefs along the ~ 1500 km tropical coast of north-western Australia (NWA). Fish were caught during day and night in both dry and wet seasons at two well-spaced locations in each of the Kimberley (13–16°S), Canning (16–19°S) and Pilbara (20–22°S) bioregions. Species richness and abundance were both typically less at the two locations at the lowest latitude than at the two at the highest latitudes. This trend, which contrasts with the paradigm regarding latitudinal trends for these biotic variables, is attributable to the far more extreme hydrological conditions in the Kimberley than Pilbara. Indeed, both biotic variables peaked in the Canning, presumably reflecting, inter alia , the better development of reef and suspension feeder habitats in that bioregion. The peak in abundance was attributable to particularly high numbers of the NWA endemic Lethrinus punctulatus. A greater species richness and abundance of fishes in deeper than shallow water during the wet season, and particularly in areas of greater cyclonic activity, reflect the movement of species such as Lethrinus laticaudis and Lutjanus carponotatus from shallow to calmer, deeper waters. These two biotic variables were greater during the day than night, with a greater number and abundance of diurnally-active species, e.g. lethrinids, feeding overall in the traps than is the case with nocturnal species, e.g. lutjanids. The results imply that the typical poleward latitudinal gradients in species richness and abundance are over-ridden along the NWA coast by environmental differences among bioregions. Graphical abstract fx1 Highlights • Latitudinal changes in reef faunas do not follow the traditional paradigm. • Species richness (S) and abundance (N) were less at lowest than highest latitudes. • S and N typically peaked, however, at intermediate latitudes. • S and N were greater during the day than night reflecting diurnal feeding activity. • Results emphasise caution when generalising on characteristics of reef fish faunas. [ABSTRACT FROM AUTHOR]

Historically, piscine francisellosis in various warm-, temperate-, and coldwater fish hosts has been attributed to Francisella noatunensis. From 2015 to 2016, an undescribed Francisella sp. was recovered during mortality events in cultured spotted rose snapper (Lutjanus guttatus) off the Pacific coast of Central America. Despite high mortality and emaciation, limited gross findings were observed in affected fish. Histological examination revealed multifocal granulomatous lesions, with the presence of numerous small, pleomorphic coccobacilli, predominantly in the peritoneum, spleen, kidneys, liver, pancreas, heart, and intestine. Sequencing of an ~1,400-bp fragment of the 16S rRNA gene demonstrated these isolates to be most similar (99.9% identity) to Francisella sp. isolate TX077308 cultured from seawater in the Gulf of Mexico, while sharing >99% similarity to other Fransicella spp. Biochemical analysis, multilocus sequence comparisons of select housekeeping genes, repetitive extragenic palindromic PCR fingerprinting, matrix-assisted laser desorption ionization-time of flight mass spectrometry, and fatty acid methyl ester analysis revealed marked differences between these isolates and other described members of the genus. Koch's postulates were fulfilled by experimental intracoelomic injection and immersion trials using Nile (Oreochromis niloticus) and blue (Oreochromis aureus) tilapia. Based on observed phenotypic and genotypic differences from recognized Francisella spp., the name Francisella marina sp. nov. (NRRL B-65518) is proposed to accommodate these novel strains. [ABSTRACT FROM AUTHOR]

Abstract β-Glucans are naturally occurring polysaccharides that are produced by bacteria, fungi and yeast. They are considered immunostimulants in fish acting on non-specific defense mechanism. Yeast-derived glucans from cell wall ( Sterigmatomyces halophilus , β-Gluc/Sh) have been used for this purpose in this study. Therefore, an in vitro assay using peripheral blood leucocytes (PBLs) from Pacific red snapper was performed to evaluate the stimulant effects of β-Gluc/Sh and zymosan A (positive control) for 12 and 24 h and after bacterial challenge with Aeromonas hydrophila at 24 h. In addition, structural characterization of this marine yeast glucan was performed by proton nuclear magnetic resonance (NMR) revealing structures containing (1-6)-branched (1-3)-β-D-glucan. PBLs responded positively to β-Gluc/Sh where cell viability was higher than 80%. After challenge, β-Gluc/Sh was able to inhibit cytotoxicity caused by A. hydrophila , highlighting that the PBLs incubated with β-Gluc/Sh significantly increased the non-specific immune response, such as phagocytic activity, respiratory burst, nitric oxide and peroxidase activities followed by an increase in superoxide dismutase and catalase activities after 12 and 24 h post-stimulation and after challenge with the pathogen. Regarding induction of antioxidant gene expression, it was more pronounced in stimulated β-Gluc/Sh leucocytes compared to other groups at all experimental times of the trial and after bacterial challenge. Indeed, our results clearly showed the ability of leucocytes to strongly react to β-Gluc/Sh with an increase in cytokine gene expression, particularly the IL-1β , IL-10 and IL-17 genes. These results confirm that S. halophilus yeast-derived β-glucan, isolated from an extreme marine environment, is beneficial for increasing innate immune response and enhancing resistance against A. hydrophila in vitro. Highlights • Sterigmatomyces halophilus β-glucan enhances immune parameters in fish leukocytes. • Structural characterization by (NMR) revealing (1-6)-branched (1-3)-β-D-glucan. • β-Gluc/Sh was able to inhibit cytotoxicity caused by A. hydrophila in PBLs. • Antioxidant SOD and CAT activity was increased in β-Gluc/Sh-stimulated PBLs. • Cytokine gene expression confirms the immunoestimulatory effects of β-Gluc/Sh. [ABSTRACT FROM AUTHOR]

Abstract: The main purpose of this study was to review the growth models used in fish culture and demonstrate the benefit of using the most appropriate growth model for aquaculture studies. For this reason, another part of this study was to use a dataset from spotted rose snapper (Lutjanus guttatus Steindachner, 1869) cultured in floating cages to determine what growth models were applicable to this species. A total of 558 weight‐at‐age data points from a commercial farm located near Nayarit, Mexico were used. The fish were cultured for 270 days in three cages of 125 m3 capacity. The initial density was 25 fish m−3, with an average weight of 2.07 ± 0.52 g. Four asymptotic models (von Bertalanffy growth model, a logistic model, the Gompertz growth model and the Ratkowsky modified model), three nonasymptotic models (exponential, power extended and persistence models) and three versions of the generalized Schnute model were selected as candidate models. The best model was selected based on the Akaike information criterion. The maximum log‐likelihood algorithm was used to parameterize the models considering a multiplicative error structure. The survival was 90%, and the average final weight was 429.84 ± 31.53 g. We concluded that the best model for describing the growth of spotted rose snapper farmed in marine floating cages was the Schnute model. [ABSTRACT FROM AUTHOR]

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In Mexico, marine finfish cage culture is envisioned as an economic alternative for coastal fishermen. Because research and outreach have not yet proved that this is profitable, assessing the investment through financial risk assessment and setting reference points for expected outcomes is useful. For Lutjanus guttatus, this research reports on a 10-year investment analysis of a pilot-scale, ongrowing four-cage module tested in Mazatlán, Mexico that incorporated a) hatchery-reared fry, b) species-specific feed and c) a second-generation prototype cage, all of them results of almost a decade of research. Two production scenarios were examined: Scenario I, with a high survival rate (90%-95%) and a low feed conversion ratio (FCR) (1.4-1.7), and Scenario II, with a low survival rate (67%-75%) and a high FCR (1.8-2.0). The net present value results are positive for Scenario I (mean = US$134,709, and a 95% probability interval (PI) [US$91,621; US$176,436]) and negative for Scenario II (mean = US-$79,082, 95% PI [US-$116,140; US-$42,054]). To identify feasibility improvement, reference points (threshold values) for survival, FCR, fry and feed costs were determined. [ABSTRACT FROM AUTHOR]

These case studies endeavor to report incidences of caudal fin deformities in several commercial fishes living in natural populations in the Saudi Arabian coastal waters of the Arabian Gulf. Two groups of anomalies were observed, slight and severe. The carangid species, Parastromateus niger (Bloch) and the soleid species, Euryglossa orientalis (Bloch & Schneider), had slight cases of caudal fin abnormalities, while the species Oreochrromis mossambicus (Peters), Epinephelus stoliczkae (Day), Diagramma pictum (Thunberg), Cephalopholis hemistiktos (Rüppell), Lethrinus nebulosus (Forssk l), and Lutjanus sanguineus (Cuvier) had severe deformities. The abnormalities were assessed by morphological diagnosis. None of the cases was fatal as they occurred in adult individuals. The possible causes for these deformities as well as the suitability of this kind of case study for environmental monitoring are discussed. Further studies should be conducted from the perspective of pollution. [ABSTRACT FROM AUTHOR]

Small perch-like fishes from the Oligocene of the Paratethys have been traditionally assigned to Serranus budensis (Heckel, 1856). A morphological revision of the holotype and specimens previously assigned to S. budensis from the Outer Carpathians, Poland, is provided herein. They are re-assigned to the species Oligoserranoides budensis (Heckel, 1856) -- Percoidei incertae sedis. New specimens assigned to Ol. budensis from the Outer Carpathians, Poland, are introduced. Our results reveal that Ol. budensis is very similar to the species Caucasoserranoides morozkiensis, Carpathoserranoides brnoensis, Carpathoserranoides polonicus, and Oligoserranoides comparabilis, and further studies are necessary to revise the validity of those species. Ol. budensis shares many characters with genera Lutjanus and Ocyurus of the superfamily Lutjanoidea. Ol. budensis differs from Lutjanoidea in having a toothless palatine. The palaeobiogeography of Oligocene small perch-like fishes in the Paratethys is presented and discussed. [ABSTRACT FROM AUTHOR]

The habitat and dietary requirements necessary to ensure optimal survivorship and growth of settled juveniles L. argentimaculatus are poorly-known. This study examined ontogenetic diet shift in juvenile mangrove red snapper in coastal areas of central Vietnam. Juvenile fish of various size classes were captured in two widely-separated coastal locations, and their stomach contents analysed. Subsequently, the importance of providing natural prey for cultured juvenile fish was investigated. Strong differences were found between the diets of fish at different ontogenic stages, and smaller differences appeared to reflect feeding habits during different tidal cycles. In nature, the smallest juveniles fed almost exclusively on mysid shrimps and lesser amount of copepods and luciferid shrimps, while larger juveniles fed predominantly on sergestid shrimps in addition to grapsid crabs and terapontid fishes. Feeding intensity appeared to be maximal on the incoming tide for all size classes. Inclusion of the dominant prey found in wild fishes' stomachs (Acetes and Mysidae) in juvenile culture of L. argentimaculatus improved growth and survival of juvenile fish during culture. Mysid and sergestid shrimps comprise an important part of juvenile diet for all size classes, and the addition of such live food in juvenile culture is likely to create productivity gain for the industry. [ABSTRACT FROM AUTHOR]

Severe infections of the spotted rose snapper Lutjanus guttatus resulting from dactylogyrid monogeneans present a risk to aquaculture. Currently, the diagnosis of this infection requires the morphological identification and manual quantification of parasites. Based on the characterization of the 28S rRNA gene of dactylogyrid species present in L. guttatus, specific primers were designed for real-time polymerase chain reaction (qPCR) using EvaGreen® chemistry. The standard curve method estimated the number of dactylogyrids accurately. A total of 85 gill samples from cage-cultured fish infected with dactylogyrids were analysed. The estimated number of dactylogyrids using this molecular method was very similar to the manual count that was performed initially. The standardized qPCR approach will be helpful as a complementary method for the early routine monitoring of dactylogyrid infections and for epidemiological studies in which a high number of fish must be studied. [ABSTRACT FROM AUTHOR]

The objective of this study was to evaluate stress responses in dog snapper (Lutjanus jocu) during transport by evaluating their hematological and biochemical responses. Twenty-five wild dog snapper specimens were used in the experiment (220 ± 68 g and 24.5 ± 2.5 cm total length). Blood samples were collected prior to transport (control), and fish were placed in two transport boxes, one with anesthetic and one without anesthetic. Immediately after transport and after 24 h, blood was collected from the fish that underwent each treatment (with anesthetic and without anesthetic). Biochemical and hematological results demonstrated the inefficiency of benzocaine as a stress reliever during handling and transport. Biochemical parameters revealed the effects of stress during transport, and after 24 h, glucose levels and hematological parameters (hemoglobin, erythrocytes, leukocytes, neutrophils and MCH) showed a tendency to return to control levels. This study is the first to report stress response measurements of hematological and biochemical indicators in dog snapper, representing an important basis for the planning of future experiments involving the transport and handling of this fish species. [ABSTRACT FROM AUTHOR]

Understanding the drivers of dispersal among populations is a central topic in marine ecology and fundamental for spatially explicit management of marine resources. The extensive coast of Northwestern Australia provides an emerging frontier for implementing new genomic tools to comparatively identify patterns of dispersal across diverse and extreme environmental conditions. Here, we focused on the stripey snapper ( Lutjanus carponotatus), which is important to recreational, charter-based and customary fishers throughout the Indo-West Pacific. We collected 1,016 L. carponotatus samples at 51 locations in the coastal waters of Northwestern Australia ranging from the Northern Territory to Shark Bay and adopted a genotype-by-sequencing approach to test whether realized connectivity (via larval dispersal) was related to extreme gradients in coastal hydrodynamics. Hydrodynamic simulations using CONNIE and a more detailed treatment in the Kimberley Bioregion provided null models for comparison. Based on 4,402 polymorphic single nucleotide polymorphism loci shared across all individuals, we demonstrated significant genetic subdivision between the Shark Bay Bioregion in the south and all locations within the remaining, more northern bioregions. More importantly, we identified a zone of admixture spanning a distance of 180 km at the border of the Kimberley and Canning bioregions, including the Buccaneer Archipelago and adjacent waters, which collectively experiences the largest tropical tidal range and some of the fastest tidal currents in the world. Further testing of the generality of this admixture zone in other shallow water species across broader geographic ranges will be critical for our understanding of the population dynamics and genetic structure of marine taxa in our tropical oceans. [ABSTRACT FROM AUTHOR]

CD40 is known as “master switch” in immune response to pathogen infection in mammals. However, limited information of CD40 is known in lower vertebrates. In this study, a novel CD40 homolog (Ls-CD40) was cloned and characterized from humphead snapper, Lutjanus sanguineus . The Ls-CD40 cDNA composed of 2073 bp with a 69 bp of 5′-UTR, a 1020 bp of 3′-UTR and an open reading frame (ORF) of 984 bp, encoding 327 amino acid residues. Sequence analysis showed that Ls-CD40 contained a single peptide, a transmembrane domain and four cysteine-rich domains. The deduced amino acid sequence of Ls-CD40 shared 40%–53% identities with other known fish CD40. The qRT-PCR showed that Ls-CD40 gene expressed in all examined tissues with the most abundant in spleen and lowest level in intestine. After V. harveyi and poly I:C stimulation, the expression of CD40 were significantly induced in spleen. Moreover, Ls-CD40 could interact with Ls-TRAF3 in vitro . These data indicate that Ls-CD40 might play a regulatory role in immune response of L. sanguineus . [ABSTRACT FROM AUTHOR]

The climatic conditions in saltern saline environments allows the growth of microorganisms adapted to these peculiar ambient and could represent a promising source of new bioactive compounds that could have applications on as animal food supplements, including aquaculture. In this study, we evaluated the role of Yarrowia lipolytica N-6 isolate, from a hypersaline natural environment (Guerrero Negro, Baja California Sur, Mexico), as immunostimulant of the non-specific immune response of head-kidney and spleen Pacific red snapper ( Lutjanus peru ) leukocytes after challenge with Vibrio parahaemolyticus . In this study, the presence of Y. lipolytica reduced considerably the V. parahaemolyticus load in spleen leukocytes. In vitro assays using head-kidney and spleen leukocytes showed that the response to V. parahaemolyticus infection reveled that leukocyte pre-incubated with Y. lipolytica N-6 significantly increased the non-specific immune response such as respiratory burst, phagocytic activity, NO and MPO activities follow by an increase in SOD and CAT activities, and at the same time inhibited leukocyte apoptosis caused by V. parahaemolyticus . Moreover, Y. lipolytica N-6 incubation also regulated the transcription of genes related to immunity (IL-1β) or oxidative stress (MnSOD, icCu/ZnSOD or CAT) in leukocytes. These results strongly support the idea that the extreme yeast Y. lipolytica N-6 isolate can stimulate the non-specific immune parameters and the antioxidant immune mechanism in head-kidney and spleen Pacific red snapper leukocytes and could be used as potential immunostimulant. [ABSTRACT FROM AUTHOR]

The main goal of this research was to investigate the differences in diet composition among three species of the genus Lutjanus inhabiting a coastal lagoon as juveniles. The working hypothesis was that these species feed on a common base of food resources and therefore, some niche overlap is present in terms of general diet composition. However, changes in the trophic niche with size and differences in some morphological traits among species explain observed differences in diet. Fish were collected during 42 sampling trips conducted regularly from February 2011 to January 2012 using several types of fishing gear. Total number of analyzed stomachs was 288 for Lutjanus argentiventris from 2.3 to 19.9 cm total length (TL); 178 for Lutjanus colorado ranging from 2.4 to 30.1 cm TL; and 183 for Lutjanus novemfasciatus with 1.2 to 20.0 cm TL. Results indicate that juveniles of all three lutjanid species share a general diet based on decapods and fishes. However, L. novemfasciatus has a more piscivorous habit, which can be explained by a more slender body shape and larger teeth, characteristics, which increase fish catching performance. Larger fish of all three species eat larger prey, which is consistent with the optimum foraging theory. [ABSTRACT FROM AUTHOR]

The helminth communities of L. guttatus from Mazatlan Bay (MB) and Banderas Bay (BB), on the Pacific coast of Mexico, were studied during two consecutive years. A total of 536 fish were collected and 19 parasite taxa registered (six digeneans, two cestodes, nine nematodes, and two monogeneans). Infection levels of common helminth species (Helicometrina nimia, Siphodera vinaledwardsii, Tetraphyllidea gen. sp., Pseudoterranova sp., Ancyrocephalidae gen. sp. and Microcotyloides incisa) as well as the infracommunity indices varied signifi cantly between MB and BB, and among dry and rainy seasons; however, no clear seasonal patterns were observed. Pseudoterranova larvae appeared frequently in MB, possibly because of the presence of the California sea lion in this locality. Similarity analysis did not show a clear separation of parasite species composition between both localities, which suggest that fish samples came from a single population of L. guttatus. [ABSTRACT FROM AUTHOR]

Ontogenetic development of digestive system in crimson snapper ( Lutjanus erythopterus Bloch 1790) larvae was histologically and enzymatically (alkaline phosphatase, amylase, lipase, pepsin, trypsin) examined from hatching to 36 days post hatching ( DPH). The ontogenetic development of crimson snapper larval fish ontogeny was divided into three distinct phases: phase I starting from hatch to the onset of exogenous feeding, phase II starting from first feeding (2-3 DPH) until the formation of gastric glands (13-14 DPH) and phase III beginning from the appearance of gastric glands and continuing onwards. The specific activities of amylase, lipase, trypsin showed sharp increase and reached to the maximum from hatch to 4 DPH, 10 DPH, 20 DPH, respectively, followed by a declining trend with irregular fluctuation. In contrast to other enzymes, the specific activities of alkaline phosphatase showed a gradual increase from hatch to 29 DPH, followed by a sharp increase towards 36 DPH. The specific activity of pepsin was firstly detected on 17 DPH and gradually increased towards the end of this study. The total activities of these five enzymes showed a gradual increase till 29 DPH, followed by a sharp increase towards 36 DPH except for amylase and lipase reaching maximum at 32 DPH. The present study provides better understanding of the digestive ontogeny of crimson snapper during the larval stage and a guide to feeding and weaning of this economically important fish in hatcheries. [ABSTRACT FROM AUTHOR]

Ages of cubera snapper, Lutjanus cyanopterus (Cuvier, 1828) (n = 106), collected from the southeastern United States coast from 2001 to 2015, were determined using sectioned sagittal otoliths. We determined that opaque zones were annular, forming April-August (peaking in May-June). Cubera snapper ranged from 4 to 55 yrs, and the largest fish measured 1422 mm total length (TL). Body-size relationships for cubera snapper were: TL = 1.02 FL + 12.76 (n = 28, r2 = 0.99), FL = 0.97 TL - 9.65 (n = 28, r2 = 0.99), and W = 4.9 x lO-9 TL3.16 , where W is total weight (kg) and FL is fork length (mm). The von Bertalanffy growth equation for cubera snapper was Lt = 1495 (1 - e-005(t+ 3.33)) (n = 106). Point estimate of natural mortality was M = 0.08, while age-specific estimates of M ranged 0.50-0.05 y r-1for ages 1-55. Here, we present the first published findings of life history parameters for cubera snapper from the Atlantic waters off the southeastern United States. These data contribute to filling in gaps of basic biological information for data-limited reef fish species in the southeastern United States. [ABSTRACT FROM AUTHOR]