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The entire Socotra Archipelago is recognized as a UNESCO World Heritage Site. The unique ichthyofauna of Socotra accumulates fish species from different ecoregions, including commercial species which represent an important part of the local fishery. Positive identification of fish species and knowledge of their distributions are important for management strategies in fisheries and biodiversity conservation. Commercial fish species were collected at sea, taken from fish markets or landing sites, or observed underwater during two field trips in 2018 and 2019. Twenty-three new records of commercial fish species from twelve families are reported from the Socotra Archipelago based on collections and/or photographs: Plicomugil labiosus (Valenciennes, 1836); Epinephelus magniscuttis Postel, Fourmanoir et Guézé, 1963; Epinephelus marginatus (Lowe, 1834); Epinephelus morrhua (Valenciennes, 1833); Epinephelus rivulatus (Valenciennes, 1830); Alectis indica (Rüppell, 1830); Carangoides fulvoguttatus (Forsskål, 1775); Parastromateus niger (Bloch, 1795); Selar crumenophthalmus (Bloch, 1793); Uraspis helvola (Forster, 1801); Gerres oblongus Cuvier, 1830; Etelis coruscans Valenciennes, 1862; Diplodus omanensis Bauchot et Bianchi, 1984; Polysteganus coeruleopunctatus (Klunzinger, 1870); Lethrinus crocineus Smith, 1959; Gymnocranius elongatus Senta, 1973; Gymnocranius sp.; Wattsia mossambica (Smith, 1957); Argyrosomus japonicus (Temminck et Schlegel, 1843); Umbrina robinsoni Gilchrist et Thompson, 1908; Polydactylus plebeius (Broussonet, 1782); Histiopterus typus Temminck et Schlegel, 1844; and Siganus sutor (Valenciennes, 1835). The presence of the following three species are confirmed for Socotra Archipelago: Epinephelus malabaricus (Bloch et Schneider, 1801); Pristipomoides filamentosus (Valenciennes, 1830); and Sphyraena obtusata Cuvier, 1829. The following species represent the first verified records for the Arabian region: Epinephelus magniscuttis, Etelis coruscans, Lethrinus crocineus, Wattsia mossambica, and Gymnocranius sp. Species of two families, Sciaenidae and Polynemidae are reported for Socotra for the first time. Information on each species’ identification and its distribution are provided. Twenty-three commercial species new for the Socotra Archipelago were reported in this study, as a result, a total of about 255 species of fish are considered as exploited in the local small-scale fishery.

The dusky grouper Epinephelus marginatus is predator fish subjected to be impacted due to the contamination of their habitats. A viable source of metal contamination, i.e., copper (Cu), in this species is the ingestion of contaminated food. The objective of this work was to verify the toxic effects of Cu contaminated feed in dusky grouper. A 15 days trial was conducted with three treatments: control, 1 g and 2 g Cu/kg of fish feed. After the trial, the gut was analyzed for Cu concentration and the liver for SOD and GST activity. The Cu concentration in the intestinal tract was significantly greater in fish from contaminated treatments when compared with control. The SOD was significantly lower in contaminated fish, and the GST did not show differences among treatments. Copper showed to be toxic for the species, as evidenced by gut accumulation and suggested by SOD response.

Biogeographical transition zones are important areas to investigate evolutionary ecological questions, but long-term population monitoring is needed to better understand ecological processes that govern population variations in such edge environments. The southernmost Brazilian rocky reefs are the southern limit of distribution for 96% of the tropical ichthyofauna of the western Atlantic. The Arvoredo Marine Biological Reserve is the only nearshore no-take marine-protected area (MPA) located in this transition zone. The main aim was to investigate how the populations of rocky reef fish species vary in density and biomass in space and over time, inside and outside the Arvoredo MPA. This study presents results based on a 9 year (2008-2017) underwater visual census monitoring study to evaluate the density and biomass of key fish species. Variations in density and biomass were detected for most species. Factors and mechanisms that may have influenced spatial variation are habitat structural complexity and protection from fisheries. Temporal variations, otherwise, may have been influenced by species proximity to their distributional limit, in synergy with density-dependent mechanisms and stochastic winter temperature oscillations. The MPAs harbour higher density and biomass for most species. Nonetheless, a prominent temporal decline in the recruitment of Epinephelus marginatus calls into question the continuous effectiveness of the MPA.

Made available in DSpace on 2020-12-12T02:11:23Z (GMT). No. of bitstreams: 0 Previous issue date: 2020-10-01 Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) Sex change was induced in Epinephelus marginatus juveniles using a nonsteroidal aromatase inhibitor (AI), a synthetic androgen (17α-methyltestosterone; MT), and a combination of both (MT + AI) in a 90-day experiment. A detailed remodeling of the gonads, the plasma level of gonadal steroids, and immunostaining of pituitary follicle-stimulating hormone (FSH), luteinizing hormone (LH), and somatolactin (SL) cells were analyzed. Sex inversion reached the final spermatogenesis stages using MT, while AI triggered spermatogenesis, but reaching only the spermatid stage. Estradiol (E2) levels did not change in fish treated with AI but decreased throughout the experimental period in animals treated with MT and MT + AI. Testosterone (T) levels increased in animals treated with MT during the first 60 days (and combined with AI in the first 30 days), decreasing in all experimental groups at 90 days, while AI-treated animals had increased plasma 11-ketotestosterone (11-KT) levels after 90 days. In control fish, FSH- and SL-producing cells (ir-FSH and ir-SL) were restricted to pars intermedia (PI) of the adenohypophysis. Pituitary ir-FSH cells were decreased at the end of the experimental period in all treatments compared with the CT animals. LH-producing cells (ir-LH) were present in proximal pars distalis (PPD) and pars intermedia (PI) of adenohypophysis and did not change after the experimental period. The decreased number of ir-FSH cells at the end of the experiment in all treatments could be related to the negative feedback loop triggered by the increase in natural and/or synthetic androgens. Departamento de Fisiologia Instituto de Biociências Universidade de São Paulo Fundação Instituto de Pesca do Estado do Rio de Janeiro (FIPERJ) Departamento de Biologia Celular e do Desenvolvimento Instituto de Ciências Biomédicas Universidade de São Paulo Instituto de Pesca-APTA/SAA Facultad de Ciencias Exactas y Naturales Departamento de Biodiversidad y Biología Experimental Instituto de Biodiversidad y Biología Experimental Aplicada (IBBEA) Laboratorio de Ecotoxicología Acuática CONICET-Universidad de Buenos Aires Centro de Aquicultura da UNESP (CAUNESP) Centro de Aquicultura da UNESP (CAUNESP) FAPESP: 2007/57106-4 FAPESP: 2007/59122-7 CNPq: 558992/2009-9

Los nodavirus afectan a gran número de especies de peces, silvestres y cultivadas. En silvestres se ha aislado en diversas especies, pero nunca se había asociado con procesos clínicos en el litoral de Murcia. En otoño de 2017, se detectaron diversos ejemplares de meros (Epinephelus marginatus y E. costae) en la Reserva de Cabo de Palos con sintomatología clínica compatible con nodavirus. La infección por nodavirus fue confirmada mediante RT-PCR en tiempo real y su posterior genotipado (tipo RGNNV). Este hallazgo constituye la primera evidencia regional de infección clínica por nodavirus en peces silvestres, con la relevancia añadida de que la especie afectada es la especie emblemática de la Reserva Marina de Cabo de Palos, el mero. Nodaviruses affect a large number of fish species, wild and farmed. In the wild it has been isolated in various species, but it had never been associated with clinical processes on the coast of Murcia. In autumn 2017, several specimens of groupers (Epinephelus marginatus and E. costae) were detected in the Cabo de Palos Reserve with clinical symptoms compatible with nodavirus. The infection by nodavirus was confirmed by real time RT-PCR and its subsequent genotyping (RGNNV type). This finding constitutes the first regional evidence of clinical infection by nodavirus in wild fish, with the added relevance that the affected specie, the grouper, is the emblematic specie of the Cabo de Palos Marine Reserve.

Ceratomyxa mennani n. sp. is a new coelozoic Ceratomyxa species found in the gallbladder of Epinephelus marginatus from the Gulf of Tunis, Tunisia. Mature plasmodia were disporic, ovoid in shape measuring 9-12 μm in width and 11-14 μm in length. Mature myxospores were slightly crescent-shaped with almost straight posterior margin, measuring 5.8 ± 0.2 (5.4-6.1) μm in length and 12.7 ± 0.3 (11.9-13.0) μm in thickness. The two valves were unequal with rounded ends. Polar capsules were spherical, equal in size with 2.1 ± 0.2 (1.9-2.6) μm in diameter. The binucleated sporoplasm filled the entire cavity of the myxospore. Molecular analysis of SSU rDNA sequences indicated that C. mennani n. sp. was distinct from all other Ceratomyxa sequences in GenBank. Phylogenetic analysis revealed that C. mennani n. sp. clustered with Ceratomyxa species infecting Epinephelinae fishes. Seasonal prevalence of infection over one year was significantly higher in winter and the lowest in autumn. This is the third report of Ceratomyxa species infecting the gallbladder of Epinephelus marginatus from Tunisia and the first study to include molecular data.

This study aimed to investigate parasite fauna of E. marginatus from the central Mediterranean Sea between Messina and Syracuse. In the present survey, parasite fauna of dusky grouper was investigated for two main reasons: the economic value of this species and the current lack of studies regarding the capture area. Seventy dusky groupers were caught from May 2018 to February 2020. Forty-seven out of the 70 specimens (67.2%) were infected with one or more parasite species. The most abundant species was Prosorhynchus caudovatus (42.9%), followed by Podocotyle temensis (28.6%), Didymodiclinus sp. (18.6%), Philometra jordanoi (5.7%), Anisakis Type II larvae (5.7%). Higher prevalence of infection of P. jordanoi and Contracaecum sp. was found in warm months (March to September), while P. caudovatus and P. temensis were mostly found during cold months. Weight and total length of E. marginatus were positively correlated with the parasitic load of P. jordanoi and Didymodiclinus sp. The different prevalence of parasite infection found between warm and cold months is probably related to the diet of the dusky grouper, which is characterized by mollusks that are intermediate hosts for parasite species found. None of the parasites found in the present survey is responsible for zoonosis

The silver-cheeked toadfish (Lagocephalus sceleratus, from the pufferfish family Tetraodontidae) and the Pacific red lionfish (Pterois miles, family Scorpaenidae) have recently invaded the Mediterranean Sea. Lagocephalus sceleratus has spread throughout this entire sea with the highest concentrations in the eastern basin, while more recently, Pterois miles has spread from the Eastern to the Central Mediterranean Sea. Their effects on local biodiversity and fisheries are cause for management concern. Here, a comprehensive review of predators of these two species from their native Indo-Pacific and invaded Mediterranean and Western Atlantic ranges is presented. Predators of Tetraodontidae in general were reviewed for their native Indo-Pacific and Western Atlantic ranges, as no records were found specifically for L. Sceleratus in its native range. Tetraodontidae predators in their native ranges included mantis shrimp (Stomatopoda), lizardfish (Synodus spp.), tiger shark (Galeocerdo cuvier), lemon shark (Negaprion brevirostris), sea snakes (Enhydrina spp.), catfish (Arius spp.), cobia (Rachycentron canadum), skipjack tuna (Katsuwonus pelamis), and common octopus (Octopus vulgaris). The only reported predator of adult L. sceleratus in the Mediterranean was loggerhead turtle (Caretta caretta), whereas juvenile L. Sceleratus were preyed by common dolphinfish (Coryphaena hippurus) and garfish (Belone belone). Conspecific cannibalism of L. sceleratus juveniles was also confirmed in the Mediterranean. Pufferfish predators in the Western Atlantic included common octopus, frogfish (Antennaridae), and several marine birds. Predators of all lionfish species in their native Indo-Pacific range included humpback scorpionfish (Scorpaenopsis spp.), bobbit worms (Eunice aphroditois), moray eels (Muraenidae), and bluespotted cornetfish (Fistularia commersonii). Lionfish predators in the Mediterranean included dusky grouper (Epinephelus marginatus), white grouper (Epinephelus aeneus), common octopus, and L. sceleratus, whereas in the Western Atlantic included the spotted moray (Gymnothorax moringa), multiple grouper species (tiger Mycteroperca tigris, Nassau Epinephelus striatus, black Mycteroperca bonaci, red Epinephelus morio, and gag Mycteroperca microleps; Epinephelidae), northern red snapper (Lutjanus campechanus), greater amberjack (Seriola dumerilli), and nurse shark (Ginglymostoma cirratum). The sparse data found on natural predation for these species suggest that population control via predation may be limited. Their population control may require proactive, targeted human removals, as is currently practiced with lionfish in the Western Atlantic., peer-reviewed

Invasive species are one of many anthropogenic challenges to maintaining a healthy marine ecosystem. Two rabbitfish species (Siganus rivulatus and Siganus luridus) are among the more successful migrants from the Red Sea to the Mediterranean, where their intense foraging has caused damage to the algae community, thus reducing primary production and habitat complexity, and impacting nurseries for early life stages. Anecdotal evidence suggests that the impact of rabbitfish on algae is lower in Marine Protected Areas (MPAs) although rabbitfish densities are similar in protected and fished areas. One explanation could be that fear of predators, more often present inside MPAs and an important component of a healthy marine ecosystem, reduces the ecological impacts of rabbitfish. This research aimed to test if such fear effects do occur in rabbitfish. Using controlled mesocosm experiments, we tested S. rivulatus reactions to two chemical predation cues: chemical alarm cues released from a recently killed conspecific fish, and water-borne cues from a tank with a live grouper predator, Epinephelus marginatus. We found that rabbitfish significantly reduce their overall food consumption as well as their bites per minute when exposed to the alarm cue, but not when exposed to the grouper water cue. These results support the idea that MPAs, which effectively increase the density of large piscivores and hence predation, can mitigate the impact of invasive herbivorous species. If the mesocosm results can scale up to natural systems, predation cues may be artificially introduced to other target areas in order to reduce rabbitfish grazing outside reserves. Thus, this study provides information that can be used to manage the ecological impacts caused by invasive rabbitfish, both inside and outside of marine reserves.

Salt‐water recirculation systems using automatic feeders are a new frontier for marine aquaculture. The definition of the feed frequency is fundamental for the correct use of automatic feeders. Different feeding frequencies (1, 3, 6, 12 and 18 times a day) using automatic feeders were evaluated in two experiments on the performance of the dusky grouper (Epinephelus marginatus) in salt‐water recirculation system. In the first experiment, three feeding frequencies were evaluated: feeding once a day; three times a day and six times a day. In the second experiment, three feeding frequencies were evaluated: feeding six times a day; 12 times a day and 18 times a day. Waters parameters (temperature, salinity, oxygen level, total ammonia, pH and oxidation‐reduction potential) were maintained at specific ranges for the species. Among all the evaluated frequencies, 12 times a day provided the best productive performance, obtaining superior results for final weight, final biomass, specific growth rate and daily weight gain. For juveniles of the dusky grouper, the ideal feeding frequency is regular feedings every 2 hours, which is impractical to run without the use of automatic feeders.

The dusky grouper, Epinephelus marginatus, is a well-known and widespread marine fish assessed as endangered by the International Union for the Conservation of Nature. Analyzing the genetic diversity of this species is, therefore, of utmost importance and necessary for conservation purposes. Microsatellites are molecular tools with advantages that are ideal for population analyses. This study provides the first set of species-specific microsatellite loci for E. marginatus that can be applied when assessing both intra- and interpopulation genetic variation. Twenty microsatellite loci were isolated and characterized for the dusky grouper by genotyping 20 individuals obtained from the North Eastern Atlantic Ocean (n = 4) and from the South Western Atlantic Ocean (n = 16). The number of alleles per locus varied from 2 to 11, while the observed and expected heterozygosities ranged from 0.25 to 0.94 and 0.34 to 0.89, respectively. The polymorphic information content varied from moderately to highly informative. This suite of markers provides the first specific nuclear tools for E. marginatus and, thus, allows to assess with more specificity different populations’ structures.

Identification of fish processing methods and their long-term preservation in Antiquity is not an easy task. In this article we present unique evidence of fish butchery methods, based on an analysis of fish remains recovered from the coastal, Late Bronze Age (LBA) (14th -13th century BCE) site of Tell Abu Hawam (TAH; southern Levant). Based on fish butchered today by traditional fishing communities, we developed an ethnographic-taphonomic model enabling us to identify the exact butchery method applied to a dusky grouper (Epinephelus marginatus; Lowe, 1834) recovered at TAH. This model verifies, for the first time, the antiquity of traditional fish butchery and preservation methods, and reveals their similarity to the methods depicted on ancient Egyptian tomb reliefs from the Old Kingdom (ca. 2649–2150 BCE). Analysis of the entire fish assemblage expands our relatively poor knowledge of fish exploitation patterns during the LBA. At Tell Abu Hawam we found a diverse exploitation pattern, with 14 species of fish originating from two main habitats: the Eastern Mediterranean Sea (79%) and the Nile (20%; Egypt). Although rare, we also recovered the remains of several pelagic species (11%). The presence of pelagic fish was uncommon during the LBA period. We therefore assume that these fish represent either local seasonal fishing from the littoral zone or one of the earliest indications of pelagic fishing. Another possibility is that these species also represent trade connections either with the Aegean Sea or with Egypt.

Simple Summary Trypanorhyncha are common parasites of marine fish. Despite numerous studies detailing their biology, knowledge on the effects caused by these parasites in fish tissues is still limited. Dusky groupers are keystone species, necessary for the preservation of several marine ecosystems. Considering their vulnerable state of conservation and the efforts being made to culture them, identification of the effects caused by Trypanorhyncha is vital. Here, we have assessed the prevalence of Trypanorhyncha in dusky groupers from the Canary Islands and the associated pathological changes. Of the 28 fish examined, 27 presented trypanorhynch larvae. Macroscopically, in the abdominal cavity, there were numerous larvae-filled cysts and nodules embedded in abundant fibrosis, hindering the separation of the organs. Microscopically, in the peritoneum, stomach and intestine, there were numerous degenerated parasitic cysts and extensive deposition of fibrous connective tissue with minimal inflammatory responses. This study shows that Trypanorhyncha are common parasites of adult dusky groupers from the Canary Islands. Even though the immune system appears to isolate and eliminate the parasites, extensive fibrosis may have a detrimental impact on fish health when adjacent organs are compressed and their functions impaired. Abstract Trypanorhyncha are cestodes commonly infecting marine fish. Numerous studies have detailed the biology of Trypanorhyncha species, but information on the pathological changes produced by these parasites is limited. Dusky groupers are keystone species necessary for the preservation of several marine ecosystems. Considering their vulnerable state of conservation and the efforts being made to culture them, identification of the effects caused by Trypanorhyncha is vital. Here, we aimed to determine the prevalence and pathological changes produced by Trypanorhyncha in dusky groupers from the Canary Islands. The prevalence of trypanorhynch plerocerci was 96%. Grossly, in the abdominal cavity, there were numerous larvae-filled cysts and nodules. These were embedded in abundant fibrosis, producing visceral adhesions. Histologically, affecting the peritoneum, stomach, and intestine there were numerous degenerated encysted plerocerci and extensive deposition of mature connective tissue. These findings indicate that Trypanorhyncha is highly prevalent in adult dusky groupers from the Canary Islands, producing a progressive and chronic response. Furthermore, fish immune system appears to attempt to eliminate the parasites through fibrous encapsulation. Nonetheless, extensive fibrosis may have a detrimental impact on fish health when adjacent cells or tissues are compressed and their functions impaired.

The aim of this study was to determine selected molecular biomarkers of iron ore contamination in Epinephelus marginatus. Molecular biomarkers were tested by checking the relative expression of genes involved in oxidative stress, trace element regulation, and cellular damage, by RT-qPCR. Iron ore exposure caused the downregulation of ferroportin (FP) gene expression and a significant upregulation in superoxide dismutase (SOD) and cytochrome P450 1A (CYP1A) genes. Iron ore affects gene expression in E. marginatus liver, indicating that it can potentially induce toxic effects in fish. Moreover, this altered gene expression pattern may be applied in monitoring iron ore contamination in marine environments.

Sclerochronological approaches using fish otoliths provide a powerful and cost-effective means to evaluate fish responses to environmental variations in regions where there is a paucity of long-term data. We hypothesised that the dynamism in the environmental conditions associated with El Nino Southern Oscillation (ENSO) events in the Southern Atlantic Ocean would likely influence growth patterns and chemical records in fish otoliths. Hence, we developed a 46-year otolith increment-based growth chronology, and otolith chemical chronologies of Sr:Ca and Ba:Ca for an iconic top predatory fish, the dusky grouper Epinephelus marginatus collected off the southern coast of Brazil. Using a set of increasingly complex mixed-effects linear models, our biochronological approach revealed the influence of intrinsic and large-scale environmental drivers on growth and otolith chemical composition of dusky grouper. In particular, the intensity of the Multivariate ENSO index (a measure of the status of ENSO and El Nino or La Nina conditions) was negatively associated with growth, with rapid drops in average growth evident in very strong El Nino events (1992–93, 1997–98, or 2015–16). Similar negative relationships between ENSO and Ba:Ca composition reflected variations in environmental histories of dusky groupers, a species that is mostly sedentary in coastal reefs, whilst no environmental effects were detected for Sr:Ca. Overall, identifying the drivers that underlie variations in fish growth is a crucial challenge for any conservation or fisheries interest species as population dynamics, persistence and sustainable harvesting are tightly linked to individual growth. The development of chemical chronologies provided insight towards relating otolith elemental variation to environmental conditions at multidecadal scales, encouraging further evaluations of individual and population-level fluctuations of otolith chemistry and environmental reconstructions.

12 pages, 7 figures, 2 tables, iEcology and conservation culturomics are two emerging research approaches that rely on digital data for studying ecological patterns and human-nature interactions. We applied data mining of videos published on YouTube related to recreational fishing of four species of groupers (family: Epinephelidae) in Italy between 2011 and 2017 to learn whether digital user-supplied data help uncover key spatio-temporal ecological patterns characteristic of the studied species. Our results support an ontogenetic deepening of the dusky grouper (Epinephelus marginatus) as revealed by a positive relationship between body mass and depth of captures declared in spearfishing videos. In addition, the data support a northward expansion of the white grouper (Epinephelus aeneus) because the average latitude associated to the catch was found to be positively correlated with the years when the videos were uploaded on YouTube. Furthermore, the georeferenced data about the white grouper filled a knowledge gap in a well-established international occurrence records dataset. The approach presented here could help mitigating data deficiencies and inform about harvesting patterns shown by recreational anglers and spearfishers. Our work illustrates the value of digital data associated with recreational fishing for advancing fish and fisheries research. The approach can be broadened to larger spatial and temporal scales, and to different species, contributing to a better understanding of macroecological patterns, assessment and conservation of exploited species, and monitoring of recreational fisheries, VS is supported by a “Juan de la Cierva Incorporación” research fellowship (IJC2018-035389-I) granted by the Spanish Ministry of Science and Innovation. RC was partly supported by funding from the Helsinki Institute of Sustainability Science (HELSUS) and the University of Helsinki. MC acknowledges partial funding from the European Union’s Horizon 2020 research and innovation programme under grant agreement No 869300 (FutureMares). RA received funding through the European Union (European Maritime and Fisheries Fund) and the State of Mecklenburg-Vorpommern (Germany) (Grants MV-I.18-LM-004, B 730117000069), and the German Federal Ministry of Education and Research (Grants 01LC1826E and 033W046A), With the funding support of the ‘Severo Ochoa Centre of Excellence’ accreditation (CEX2019-000928-S), of the Spanish Research Agency (AEI)

The dusky grouper Epinephelus marginatus is a large epinephelid species that occurs in the eastern and south-western Atlantic and western Indian Oceans. Late maturity, protogynous hermaphroditism, site fidelity, and overfishing have all contributed to its demographic decline. Connectivity and demography within a broad sampling of dusky grouper populations throughout its distribution were assessed. To do so, genetic variation at 11 polymorphic microsatellite loci and a partial sequence of the mitochondrial control region (mtCR) were evaluated. Two major mtCR lineages with a sequence divergence of 1.6% were found. The magnitude of genetic differentiation for mtCR among north and south Atlantic and Indian Ocean populations was high, with ΦST = 0.528. DEST and results of discriminant analysis of principal component revealed significant microsatellite genetic differentiation between all collection areas. Significant pairwise DEST showed moderate (0.084) to very great (0.603) differentiation. The effective population size was low for all localities, ranging between 25 (Azores Archipelago) and 311 (Rio Grande do Sul). The overall effective population size was estimated as 299 (confidence interval = 215–412), and there was no evidence of strong or recent bottleneck effects. Local and regional genetic structuring among dusky grouper populations is the consequence of the species' site fidelity, distribution across multiple oceanographic boundaries, and probably also of sequential hermaphroditism that contributes to the intensity of random genetic drift. The spatial pattern of genetic structuring of dusky groupers is such that fisheries management and conservation of population genetic integrity will have to be pursued at the local and regional scales. São Paulo Research Foundation (FAPESP), Grant/Award Numbers: 2015/23.883-0, 2016/20.208-3, 2017/02.420-8; Hatch Program of the National Institute of food and Agriculture, U.S. Departament of Agriculture Experiment Station; Coordenação de Aperfeiçoamento de Pessoal de Nível Superior/Brasil (CAPES). info:eu-repo/semantics/publishedVersion

Photoperiod is considered an environmental factor that influences reproduction and the growth processes of fish throughout the year. In the present study, we subjected dusky grouper Epinephelus marginatus to different photoperiods in order to evaluate growth and survival. Juvenile dusky grouper were randomly distributed in twelve 100 L tanks containing four fish per aquarium. The fish were exposed to continuous light, normal photoperiod or continuous darkness for 50 days. Fish were fed 3% of their total biomass, twice a day, and the diet consisted of ground commercial dry pellets (42% crude protein, 12% humidity, 9% ether extract, 15% mineral matter, 4% crude fiber, 3.5% calcium and 3% vitamin C, in accordance with the manufacturer’s instructions). There was no mortality during the experiment. After 50 days, the best performance was found for exposure to continuous light (24 h artificial light). The final weight of the fish reared under continuous light was significantly higher than that of the fish exposed to continuous darkness. The specific growth rate of the fish exposed to continuous light was significantly higher than that of the fish exposed to the natural photoperiod and to continuous darkness. Modifications to the photoperiod can be a key factor in increasing the efficacy of current production and the improvement of current aquaculture protocols.

Assessing individuals’ abundance, residency (presence at a site within a certain period) and site fidelity (tendency to return to the same site in subsequent seasons or years) is crucial for evaluating and improving the effectiveness of spatial conservation/management measures regarding ecologically and socio-economically valuable species. Using underwater visual census (UVC) and photo-identification (photo-ID) techniques, we estimated the abundance, residency and site fidelity of the dusky grouper, Epinephelus marginatus, at two protected sites within the Tavolara-Punta Coda Cavallo Marine Protected Area (Sardinia, Italy) in the summers of 2017–2018. The scope and spatio-temporal resolution of the study was extended by involving volunteer recreational divers in the photo collection. Grouper mean densities varied significantly across sampling dates, with a significant variability between the 2 years and the two investigated sites. At least 94 grouper visited the study sites in the summers of 2017–2018 based on the analysis of 968 high-quality photos using a semi-automated software to photo-identify individuals. Overall, the most frequently sighted grouper was recorded on 32 different days and 21 individuals (22%) identified in 2017 were re-sighted in 2018. The participation of volunteer recreational divers helped detect the inter-site (3.5–4 km apart) movements of a female and a male, supporting previous findings regarding the occurrence of reproduction-related movements. This study provides novel insights into the residency and site-fidelity patterns of the dusky grouper, and its small-scale movements probably related to reproduction. Specifically, we provide indications that effective protection from fishing should encompass the entire area used by grouper for reproductive movements.

Data concerning the monomethylmercury (MeHg) bioaccumulation in marine biota from Southeast Atlantic Ocean are scarce. This study purchased large specimens of demersal fishes from an upwelling region: Warsaw grouper (Epinephelus nigritus), Dusky grouper (Epinephelus marginatus) and Namorado sandperch (Pseudopercis numida). The authors addressed the bioaccumulation and toxicokinetic of mercury in fish organs, and the toxicological risk for human consumption of this metal in the muscle tissues accessed. Additionally, the present study discussed the possible implications of shifts in key variables of the environment related to a climate-changing predicted scenario, to the mercury biomagnification in a tropical upwelling system. The muscle was the main stock of MeHg, although the highest THg concentrations have been found in liver tissue. Regarding the acceptable maximum level (ML = 1 mg kg−1), E. nigritus and E. marginatus showed 22% of the samples above this limit. Concerning P. numida, 77% were above 0.5 mg kg−1, but below the ML. The %MeHg in liver and muscle showed no significative correlations, which suggest independent biochemical pathways to the toxicokinetic of MeHg, and constrains the indirect assessment of the mercury contamination in the edible tissue by the liver analyses. The present study highlights the food web features of a tropical upwelling ecosystem that promote mercury biomagnification. Additionally, recent studies endorse the enhancement of upwelling phenomenon due to the climate global changes which boost the pumping of mercury enriched water to the oceanic upper layer. Therefore, the upwelling areas might be hot spots for MeHg monitoring in marine biota.

This work describes betanodavirus infection in two species of groupers (family Serranidae) from the Algerian coast: the dusky grouper Epinephelus marginatus and the golden grouper Epinephelus costae. At necropsy, characteristic clinical signs, external injuries, clouded eyes and brain congestion, generally associated with viral encephalopathy and retinopathy (VER) infection were observed. The partial sequences of RNA1 and RNA2 from two viral strains were obtained, and the phylogenetic analysis revealed the presence of the red-spotted grouper nervous necrosis virus (RGNNV) genotype closely related to strains previously detected in groupers in the same geographic area. Results obtained in this study support the hypothesis that VER disease is endemic in the Algerian grouper population.

Made available in DSpace on 2019-10-06T15:21:46Z (GMT). No. of bitstreams: 0 Previous issue date: 2018-09-01. Added 1 bitstream(s) on 2019-10-09T18:34:46Z : No. of bitstreams: 1 S0102-09352018000501565.pdf: 778835 bytes, checksum: 6c5b5c029b202cb10282793b76ca53d9 (MD5) Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) As deformidades esqueléticas são problemas frequentes em populações de peixes cultivados devido, principalmente, a condições abióticas desfavoráveis, nutrição inapropriada e fatores genéticos. Estas podem causar natação errática, diminuição do índice de conversão, do crescimento e do valor no mercado. O objetivo deste relato de caso foi apresentar a ocorrência de deformidades em cobias e garoupas juvenis provenientes de uma fazenda marinha em sistema offshore, em Ilhabela, São Paulo, Brasil. Nove cobias e sete garoupas juvenis, que apresentavam deformidades, foram sujeitos à eutanásia e fixados em formol a 10%. Os espécimes foram registrados, processados e corados com Alcian Blue (AB) e Alizarin Red-S (ARS) para visualização de tecido cartilaginoso e ósseo, respectivamente. Os peixes foram eviscerados para o exame radiográfico. As deformidades observadas em cobia foram: atrofia do opérculo, desorganização das lamelas branquiais, deformidade do maxilar inferior, cifose e escoliose. As garoupas apresentaram deformidade do maxilar inferior e síndrome de Saddleback. Os peixes deste relato de caso estiveram sob manejo deficiente, alimentados com ração comercial para peixes herbívoros de água doce e sardinhas cozinhadas, alta consanguinidade e ausência de profissionais adequadamente treinados para o manejo dessas espécies. A soma desses fatores influenciou diretamente na aparição dessas deformidades, precisando ser controlados para minimizar a incidência de malformações que tenham impacto econômico para os produtores. Skeletal deformities are frequent problems in cultured fish populations due mainly to unfavorable abiotic conditions, inappropriate nutrition, and genetic factors. These may cause erratic swimming, decrease of conversion rate, growth, and market value. The aim of this case report was to present the occurrence of deformities in juvenile cobia and groupers from an offshore marine farm in Ilhabela, São Paulo, Brazil. Nine cobias and seven juvenile groupers, that presented deformities, were euthanized and fixed in 10% formaldehyde. They were tagged, processed, and stained with Alcian Blue (AB) and Alizarin Red-S (ARS) for visualization of cartilage and bone tissue, respectively. After evisceration, radiographic examination was performed. The deformities observed in cobia were atrophy of the operculum, disorganization of the gill lamellae, deformity of the lower jaw, kyphosis, and scoliosis. Groupers presented lower jaw deformity and saddleback syndrome. The farm studied in this case report had poor management standards, fed commercial feed for freshwater herbivorous fish and cooked sardines, high inbreeding and absence of adequately trained professionals to manage these species. The sum of these factors must have directly influenced the appearance of these deformities. It is necessary to control this situation to minimize the incidence of malformations that have economic impacts to farmers. Universidade Estadual Paulista (UNESP) - Caunesp Pontifícia Universidade Católica do Paraná Universidade Estadual Paulista (UNESP) - Caunesp

Two rearing conditions, tank light-dimensions and diet, were tested in dusky grouper—larvae and juveniles—in order to improve larval rearing techniques for this species. Larvae reared in high-volume and fluorescent tubes showed the highest survival rate at 18 dph (17.67%, 16%). This might be due to a higher depth and less trapping area during surface death in high-volume tanks than in low volume. Besides, a 500-lx evenly distributed light with fluorescent tubes might improve survival rate at early stages rather than illumination with energy-efficient light bulbs (4.68%, 9.64%). Light bulbs created shaded areas with less illumination inducing low larval activity. First feeding was performed with minimum rotifer lorica width of 102 ± 10.2 μm. No mixed diet was supplied. Throughout metamorphosis, stress shock syndrome appeared to be the main cause of mortality. Diet A showed best growth and survival (4.1–7.36%) during this period probably due to its high HUFA content (9.5%). Contrary to what was observed during first stages, groupers showed best performance with lower illumination. Cannibalism was observed during this period in all culture conditions.

Species functional behaviors amidst the food web, such as feeding ecology in ecosystems, are directly connected to their habitat preferences and use. In reef ecosystems, groupers and sea bass are considered key species, as top-down controllers, regulating the trophic levels on which they feed. Moreover, they are a diversified group of actinopterygian fishes, ranging from 7 to 250 cm of total length and inhabiting many types of reef habitats, from shallow waters up to 200 m deep. Due to the exceptional ecological and commercial importance of groupers and sea bass to the rocky reef systems of southwestern Atlantic and considering the small amount of information on their behavior and habitat use available for this particular region, three questions have emerged. First, how are the species spatially distributed considering the topography complexity of their environment? Second, do large Epinephelids and small Serranids have the same use of the water column, when foraging (e.g., position related to the substrate)? Third, do marine protected areas influence the distributional patterns of both families? To answer these questions, we assessed the spatial distribution and habitat use of two dominant species of groupers (Epinephelus marginatus, Mycteroperca acutirostris) and three species of sea bass (Diplectrum radiale and Serranus flaviventris and S. baldwini), using underwater visual census at Santa Catarina State, southern Brazil, during the austral summers of 2010 and 2011. All of the five sympatric species studied are directly associated with specific topographic characteristics that may be related to shelter as well as to reproduction and feeding. Except for M. acutirostris, which was mainly recorded foraging in the water column, all the remaining species are benthic dwellers. Significant evidences of effectiveness advocate that Arvoredo Marine Biological Reserve has critical importance as a refuge for heavily targeted reef species in southern Brazil, such as E. marginatus and M. acutirostris. The establishment of more protected marine areas that encompass the nursery areas near AR, along with proper enforcement, is critical to the protection of endangered and vulnerable marine species. The present work has contributed to the knowledge of habitat use and partitioning of some key reef fishes, especially target species, which is critical to effective conservation measures, including the design and management of MPAs.

Development, ontogeny of the digestive system and the fatty-acid (FA) profile, were analysed during development of Epinephelus marginatus. Larvae were analysed 7 and 17 days post fertilization (dpf) to evaluate fatty-acid profile and morphological variables, respectively. Epinephelus marginatus larvae have relatively slow development of digestive structures, but were able to capture, ingest and digest prey by 5 dpf. Eggs were composed of high percentages of polyunsaturated fatty acids (PUFA) in phospholipids. The percentage of n3 PUFAs was higher than n6, especially docosahexaenoic acid (DHA), which exhibited higher levels compared with other marine species during the first 3 days of development, both in terms of phospholipids and triglycerides. The larvae present a high content of docosahexaenoic acid-eicosapentaenoic acid (DHA-EPA) and, during this phase, live food of small size was required (copepods or SS-strain Brachionus rotundiformes), enriched with DHA-EPA. These results may guide future studies on the contribution of FAs required during this stage of the life cycle of E. marginatus, to advance knowledge of the use of these FAs throughout ontogeny and contribute to the culture of this species commercial production or restocking.

Groupers are important components of coastal ecosystems as well as a valuable resource for fisheries. Their populations are known to be decreasing throughout the world primarily due to over-exploitation. However, even the basic data for an effective management strategy is lacking. Interviews of a representative sample of 113 fishers in Turkey in the northeastern Mediterranean were conducted with specific questions regarding fishing gears, periods and areas as well as best day's catch and the sizes of fishes caught. Fishermen recognized Epinephelus marginatus, E. aeneus, E. costae, Hyporthodus haifensis, Mycteroperca rubra and Polyprion americanus distributed in the area. “Endangered” E. marginatus and “Near Threatened” E. aeneus were the dominant species of the grouper fishery. Based on best days’ catch values and reported lengths of fish caught, the northern coasts of Iskenderun Bay were found to be important for both species. Demersal longliners, spearguns, traps, anglers and demersal trawlers were reported catching groupers in the study area. Artisanal fishermen, especially demersal longliners contributed the most to the grouper fishery. Fishing pressure were subject to seasonal fluctuations, with decreasing reported catches during summer when threatened groupers spawn. Finally, some critical aspects of fishery pressure were related to the removal of juveniles which may lead to reproduction loss. © 2017 Elsevier Ltd Rufford Foundation: 20449-1 This study was performed as a part of the project “Strongholds for Groupers in Iskenderun Bay: Defining Conservation Hotspots for Sustainability” granted by The Rufford Foundation with the grant number 20449-1 . We would like to thank Ayla Yıldırım for English proofreading. Appendix A

Small-scale fisheries, demersal, in particular, are a main fishery component in the Azores archipelago, catching a high diversity of species, including “groupers” (Serranidae family) that have high commercial value and demand in the market. Blacktail comber (Serranus atricauda) and Dusky grouper (Epinephelus marginatus) dominate grouper landings, but their fishery status in the Azores is generally unknown. This study applied a length-based approach (Length-Structured Growth-Type-Group Model) to assess the status of grouper fisheries in the Azores, using length-composition data from the commercial fishery and covering distinct gear selectivity and spatial (islands) patterns. Blacktail comber is in worse condition than dusky grouper, with spawning potential ratio (SPR) estimates below 30%, which indicates that this species is fished currently at unsustainable levels in the Azores; SPR for dusky grouper, well above 30%, suggests that this species is fished at sustainable levels. Given the low SPR estimates for Sao Miguel Island, we propose to, urgently, develop, and implement management measures to ensure the recovery and sustainability of blacktail comber. Our findings support the development of management measures that take into account different selectivity by fleet (gear) and the distinct fishing strategies by island (spatial patterns). This study, the first attempt to assess the sustainability status of serranids in the Azores, highlighted limitations of the sampling coverage that deserve urgent fix, as well as other areas where improvements are critical to ensure the sustainability of these resources in the Azores.

The dusky grouper is a large-bodied marine species usually associated with rocky substrates and reefs currently experiencing increasing anthropogenic pressures. Here, we critically evaluate studies conducted during the last few decades on this endangered species, focusing on its biology, ecology, behavior, stock structure and fisheries, and identify future research directions to fill current knowledge gaps. This species plays an important functional role in the rocky bottom habitats in which it lives, usually occupying the highest trophic levels and with the potential role as a keystone species in some ecosystems. It has a complex life cycle characterized by a high longevity, a slow growth rate and a monandric protogynous hermaphroditic mode of reproduction. The species also exhibits spawning aggregation behavior, which makes it more vulnerable to fishing activity. Aside from its ecological importance, this species has high commercial value for professional fishers and is also highly prized by recreational spearfishers. These biological features, associated with increasing fishing pressures throughout most of its geographical distribution, have led to Epinephelus marginatus being included since 2004 in the IUCN Red List of Threatened Species as Endangered. Despite a large amount of research being conducted on this species over the last five decades or so, using a number of different tools and techniques, key questions regarding its biology still remain unanswered. In terms of conservation and management plans designed to safeguard this endangered species, we identified the crucial need to improve fisheries landing statistics for the species and to increase the number of marine protected areas within its distribution beyond the Mediterranean Sea.

Vibriosis is a globally threatening bacterial disease affecting mariculture with high mortalities and severe economic losses. Isolation and Identification of different vibrio species were performed to a total number of one hundred moribund and freshly dead Solea aegyptiaca, Epinephelus marginatus and Mugil cephalus collected from Lake Qarun and Gulf of Suez. Phenotypic picture and molecular identification based on use of 16SrRNA gene sequence confirmed 44 strains as vibrio species. Further molecular identification of retrieved vibrio spp. using species specific primers for collagenase, ToxR and Vvh genes categorized 10 isolates belong to V. alginolyticus, 8 isolates belong to V. parahaemolyticus and 6 isolates belong to V. vulnificus. The total prevalence of vibriosis was 44% where the highest prevalence was recorded in Lake Qarun examined fishes.

The aim of this study was to investigate a suitable packing density for the transport of juvenile dusky grouper, Epinephelus marginatus, based on the evaluation of stress responses in blood. After acclimation, fish were placed in plastic bags and transported for 8 hr on paved road at densities of 28, 45 and 64 g/L. Water quality was monitored before and after transport. Blood was collected before, upon arrival (0 hr), after 2 and 24 hr of transport. Plasma cortisol, blood glucose, partial pressures of O2 (pO2) and CO2 (pCO2), blood pH and HCO3− were evaluated. Blood smears were prepared for the verification of leucocyte profile and neutrophils:lymphocyte ratio (N:L). Blood pCO2, pH and HCO3− increased significantly after transport for all treatments compared with pre-transport. Glucose levels increased at the higher density whereas no effects were observed on plasma cortisol and pO2 levels. Upon arrival, all treatments showed lymphopenia and neutrophilia which increased N:L ratio. Although lymphopenia was observed in higher densities until 2 hr after transport, haematological parameters were fully restored within 24 hr post transport. Furthermore, no mortalities were observed throughout the experimental period. Based on the transient physiological changes observed in this study, juvenile dusky grouper can be safely transported in plastic bags for 8 hr at a density of up to 64 g/L.

Our study incorporated a comprehensive suite of parameters (i.e., body size, age, diet and trophic position) to investigate mercury concentration in dusky groupers Epinephelus marginatus. This study was carried out in rocky bottoms in littoral and neritic habitats along the Southern Brazilian coast. We also determined spatial variation in mercury concentrations in individuals inhabiting both zones, which may provide insights into how dietary differences or potential pollution sources affect bioaccumulation. A total of 244 dusky groupers was analyzed to determine total mercury concentrations. Our study revealed that when considering similar body sizes, individuals inhabiting littoral rocky habitats had higher concentrations of mercury probably due to proximity to pollution sources associated with human activities in the estuary and its drainage basin. Furthermore, large individuals (>650mm and >8years old) showed mercury contamination levels that are potentially harmful for this endangered fish species and above the acceptable limits for human consumption.

In this study 6 species of Serranidae family (Epinephelus aeneus, Epinephelus caninus, Epinephelus costae, Epinephelus marginatus, Hyporthodus haifensis, Mycteroperca rubra) were classified by using a color based feature extraction method. A database which consists of 112 fish images was used in this study. In each image, a fish was located on a white background floor with the same position and the images were taken from different distances. A combination of manual processes and automatic algorithms were applied on images until obtaining colored fish sample images with a black background. Since the presented color based feature extraction method avoids including background, these images were processed by using an automatic algorithm in order to obtain a solid texture image from the fish and extract features. The obtained solid texture image was in HSV color space and used due to extract species-specific information from the fish samples. Each of the hue, saturation and value components of the HSV color space was used separately in order to extract 7 statistical features. Hence, totally 21 features were extracted for each fish sample. The extracted features were used within Nearest Neighbor algorithm and 112 fish samples from the 6 species were classified with an overall accuracy achievement of 86%.

Groupers are highly targeted and vulnerable reef fishes. The effects of fishing pressure on the density of three reef fishes were investigated in 21 islands outside (n=15) and inside (n=6) a Marine Protected Area (MPA) at the Paraty Bay, Brazilian southeastern coast. Two valued groupers (Epinephelus marginatus and Mycteroperca acutirostris) and a non-target grunt (Haemulon aurolineatum) were studied. The total biomass of fish caught in each island was considered as a measure of current fishing pressure, while the island distance from the villages was considered as a measure of past fishing pressure. Fish densities were recordedin number and biomass. The biomass of M. acutirostris was inversely related to current fishing pressure, which did not affect the other two fishes. The density of E. marginatus increased with the island distance from one of the fishing villages, which indicated that past fishing may have had decreased the abundance of E. marginatus. Densities of the three fishes and fishing pressure did not differ between islands inside and outside the MPA. Data on fishing pressure, densities of groupers and coral cover were combined here to assign conservation scores to islands. A redefinition of MPA boundaries to reconcile fish conservation, fishing activities and fishers’ food security was proposed.

We followed landings of dusky grouper,Epinephelus marginatus, from 2013 to 2019. We observed 1,896 individuals of dusky grouper,Epinephelus marginatus, in Copacabana, Rio de Janeiro, from September 2013 to February 2019. The total weight of the catches was 6,065.57 kg, with an average of 1,442.50 kg/year and a std of 147.30 kg.We integrated fishers in our study through citizen science (CS): individuals were trained to monitor grouper gonads and supplied information on fishing spots and prices. After comparing catch curves (based on weight) and curve prices (in the Brazilian monetary currency of reals), our results showed that catches in the Copacabana fishery have been stable (the results of the Kruskal-Wallis test showed no significant difference for either the weight of the catches or the average prices of dusky groupers in the years compared). Copacabana has been a sustainable fishery when considering its catches of dusky grouper. This is a very important result for conservation and management, considering the importance of small-scale fisheries in terms of their low fishing efforts and their possible effects on vulnerable species, as well as their ecological and economic importance in developing countries. Citizen science, alomng with local ecological knowledge, helps integrate research and fisheries as well as researchers and fishers and allows for larger sampling efforts and management training for fishers.

O enriquecimento ambiental pode ser uma ferramenta importante para melhorar o desempenho produtivo da garoupa-verdadeira Epinephelus marginatus (Lowe, 1834). O objetivo deste estudo foi avaliar a preferencia por abrigos e o efeito da disponibilidade de abrigos sobre o desempenho produtivo de juvenis de garoupa-verdadeira em sistema de recirculacao de agua salgada. Foram realizados dois ensaios, o primeiro para determinar a preferencia por diferentes tipos de abrigos (pedras, tijolos e tubos de PVC de diferentes cores) e o segundo sobre o uso de abrigos, com tres tratamentos (T1 = sem abrigo; T2 = um abrigo por peixe e T3 = dois abrigos por peixe). A garoupaverdadeira mostrou preferencia por abrigos de tubos de PVC de cor marrom. O uso de abrigos favoreceu um melhor desempenho produtivo da especie em sistemas de recirculacao de agua salgada.

Background Groupers are a vulnerable but economically important group of fish, especially for small-scale fisheries. We investigated catches and local ecological knowledge (LEK) of diet, habitat, and past fishing experiences. Methods Landings, prices, interviews, and restaurants demand for two species, Epinephelus marginatus (dusky grouper) and Epinephelus morio (red grouper), were registered. Results We visited 74 markets and 79 sites on the coast of Brazil in 2017–2018, and we interviewed 71 fishers: Bahia (NE), Rio de Janeiro and São Paulo (SE), and Santa Catarina (S). The landings sampled of dusky grouper (2016–2017) in Rio de Janeiro were: n = 222, size 38–109 cm, weight 1–24 kg, average 3.84 kg; in São Paulo, São Sebastião were: n = 47, size 39–106 cm, weight 2–8 kg, average of 2.77 kg; and at Santos: n = 80, 26–120 cm, weight 0.36–15 kg, average 2.72 kg. Red grouper was observed in markets in the northeastern Brazil. We did not observe Epinephelus marginatus from Bahia northward; a maximum size of 200 cm was reported south of the Bahia, besides Rio de Janeiro and São Paulo coasts, 20 years ago (or longer) by 12 fishers. Local knowledge of fishers was important for grouper data of habitat and diet; the reproduction period was identified by fishers as September to March. Conclusions Groupers can be considered as a cultural and ecological keystone species. We suggest protective measures: 1) fishing zoning, 2) islands (MPAs) with the surveillance of fishers, 3) late Spring and early Summer as key periods for management (grouper reproduction), 4) studies on grouper larvae, 5) mapping of fishing spots, 6) studies on local knowledge. Collaboration with small-scale fishers and local knowledge could contribute to low-conflict management measures. In that regard, integrative models of management from Latin America, by using local knowledge and citizen science, could produce successful grouper management for Brazilian data-poor fisheries, a contrasting reality to the Mediterranean areas. Finally, the distribution of E. marginatus in Brazil leave us with questions: a) Have dusky groupers disappeared from Bahia because of a decline in the population? b) Was it uncommon in Northeast Brazil? c) Did changes in water temperatures forced a movement southward?

In this study, we used a historical collection of photographs taken by recreational fishers from 1940 to 2014, at the island of Gran Canaria, to show both a significant decrease in the mean total length of Epinephelus marginatus and a concurrent change in the composition of captures. Before 1980, the mean total length of fish caught and photographed was c. 100 cm, while after 2009 this was typically < 40 cm. Before 1980, the predominant captured species was E. marginatus (an apex predator), but currently the majority of catches are of omnivorous species, in particular the parrotfish, Sparisoma cretense and seabreams Diplodus spp. Overall, integration of these results indicates a qualitative and quantitative variation in captures of recreational fishers, probably as a sign of change in ecological balances and the overfished status of many target species.

This research identifies factors associated with the contamination by ciguatoxins (CTXs) in a population of fish and proposes a predictive score of the presence of CTX-like toxicity in amberjack samples from the official control program of ciguatera in the Canary Islands of the Directorate-General (DG) Fisheries (Canary Government). Out of the 970 samples of fish studied, 177 (18.2%) samples showed CTX-like toxicity. The fish were classified according to the species, amberjack (Seriola dumerili and S. rivoliana) (n = 793), dusky grouper (Epinephelus marginatus) (n = 145) and wahoo (Acanthocybium solandri) (n = 32). The data were separated by species category and statistically examined, resulting in 137 (17.3%) amberjack and 39 (26.9%) grouper samples showing CTX-like toxicity; regarding wahoo species, only 1 toxic sample (3.1%) was found. According to fishing location the contamination rates suggested grouping the islands in four clusters; namely: {El Hierro: HI; La Gomera: LG; La Palma: LP}, {Gran Canaria: GC; Tenerife: TF}, {Fuerteventura: FU} and {Lanzarote: LZ}. For the amberjack species, the multivariate logistic regression showed the factors that maintained independent association with the outcome, which were the warm season (OR = 3.617; 95% CI = 1.249–10.474), the weight (per kg, 1.102; 95% CI = 1.069–1.136) and the island of fish catching. A prediction score was obtained for the probability of contamination by CTX in amberjack fish samples. The area under de curve (AUC) obtained using the validation data was 0.747 (95% CI = 0.662–0.833). Regarding grouper species, the island of fishing was the only factor that showed significant differences associated with the presence of CTX-like toxicity. We provide herein data for a better management and prediction of ciguatera in the Canary Islands, suggesting a review of the minimum limits of fish weight established by the Canary Government for the control program. info:eu-repo/semantics/acceptedVersion

Se realizó una serie de muestreos en el intermareal rocoso al norte de la isla de Tenerife (Islas Canarias, España) con el objetivo de recopilar datos de abundancia y tallas de la especie Epinephelus marginatus (Lowe, 1834), familia Serranidae, conocida coloquialmente como mero. Esta especie es un recurso pesquero importante con una amplia distribución en zonas litorales, y cuyas zonas de cría son los charcos intermareales. En el presente estudio se muestrearon charcos al azar de diferentes volúmenes: pequeños (80 m3), con la finalidad de encontrar diferencias en la abundancia y la talla en función del tamaño del charco. Las zonas de estudio se localizaron en Punta del Hidalgo y Finca El Apio, tomando datos en 22 charcos en los cuales se contaron un total de ocho juveniles de E. marginatus. Los análisis mostraron una influencia significativa del tamaño del charco, de tal forma que los individuos de mayor talla se encontraron en los charcos de mayor volumen. A set of samplings were carried out at the rocky intertidal shore of the north of Tenerife island (Canary Islands, Spain) with the objective of compile abundance and size data from the species Epinephelus marginatus (Lowe, 1834) belonging to Serranidae family, known as dusky groupers in colloquial language. This species is an important fishing resource with a wide distribution along the rocky shores, observing juvenile populations inhabiting intertidal pools. In the present research a set of intertidal pools were sampled randomly in function of their size: smalls (80 m3) with the purpose of determine if there is an effect of this factor over the abundance and size values observed. Study area was located in Punta del Hidalgo and Finca El Apio, recording data from 22 tidalpools with a total number of 8 juveniles of E. marginatus. The statistical analysis showed a significant effect of the size of the pools, finding the biggest individuals at the biggest pools.

In the period 2013-2015, wild dusky grouper, Epinephelus marginatus (Lowe), caught in Libyan coastal waters and ranging in size from 42 to 92 cm in total length, were observed to have distinctive skin lesions of unknown aetiology. Histopathologically, the lesions comprised a multifocal, unilateral or bilateral dermatitis, involving the epidermis, superficial dermis and scale pockets, and sometimes, in severe cases, the hypodermis. Severe lesions had marked epidermal spongiosis progressing to ulceration. Healing was observed in some fish. Bacteria and fungi could be isolated from severe lesions, although they were not seen histopathologically in early-stage lesions. By contrast, metazoan parasite eggs were observed in the dermis and epidermis of some fish with mild and moderate dermatitis. Unidentified gravid digenean trematode parasites carrying similar eggs were also seen within the blood vessels of the deep and superficial dermis. The cause of this distinctive condition, termed dusky grouper dermatitis (DGD), and its potential impact upon already threatened Mediterranean wild dusky grouper populations and upon cultured grouper more widely have yet to be established.

Made available in DSpace on 2018-11-26T17:49:15Z (GMT). No. of bitstreams: 0 Previous issue date: 2018-05-01 Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) Marine Biology Center of University of Sao Paulo (CEBIMar) Dusky grouper is an important commercial fish species in many countries, but some factors such as overfishing has significantly reduced their natural stocks. Aquaculture emerges as a unique way to conserve this species, but very little biological information is available, limiting the production of this endangered species. To understand and generate more knowledge about this species, liver transcriptome sequencing and de novo assembly was performed for E. marginatus by Next Generation Sequencing (NGS). Sequences obtained were used as a tool to validate the presence of key genes relevant to lipid metabolism, and their expression was quantified by qPCR. Moreover, we investigated the influence of supplementing different dietary fatty acids on hepatic lipid metabolism. The results showed that the different fatty acids added to the diet dramatically changed the gene expression of some key enzymes associated with lipid metabolism as well as hepatic fatty acid profiles. Elongase 5 gene expression was shown to influence intermediate hepatic fatty acid elongation in all experimental groups. Hepatic triglycerides reflected the diet composition more than hepatic phospholipids, and were characterized mainly by the high percentage of 18:3n3 in animals fed with a linseed oil rich diet. Results for the saturated and monounsaturated fatty acids suggest a self-regulatory potential for retention and oxidation processes in liver, since in general the tissues did not directly reflect these fatty acid diet compositions. These results indicated that genes involved in lipid metabolism pathways might be potential biomarkers to assess lipid requirements in the formulated diet for this species. Univ Sao Paulo, Dept Fisiol, Inst Biociencias, Rua Matao,Trav 14,321, BR-05508090 Sao Paulo, SP, Brazil Univ Sao Paulo CEBIMar USP, Ctr Biol Marinha, Rodovia Manoel Hipolito do Rego,Km 131,5, BR-11600000 Sao Sebastiao, SP, Brazil CSIRO Agr & Food, Queensland Biosci Precinct, 306 Carmody Rd, St Lucia, Qld 4067, Australia Fundacao Inst Pesca Estado Rio de Janeiro, Praca Fonseca Ramos S-N, BR-24030020 Niteroi, RJ, Brazil Univ Estadual Paulista, Ctr Aquicultura CAUNESP, Via Acesso Prof Paulo Donato Castelane S-N, BR-14884900 Jaboticabal, SP, Brazil Univ Estadual Paulista, Ctr Aquicultura CAUNESP, Via Acesso Prof Paulo Donato Castelane S-N, BR-14884900 Jaboticabal, SP, Brazil FAPESP: 2011/504074 FAPESP: 2011/50287-2

The dusky grouper Epinephelus marginatus (Lowe) is an ecologically and commercially important fish species of the Atlantic and Mediterranean coastal rocky habitats. Despite records of didymozoid infections in several grouper species, the identification and pathogenesis of these parasites in E. marginatus are lacking. The aim of this study is to characterize the didymozoids of E. marginatus, particularly their mechanisms of infection and histopathological features. Dusky groupers (n = 205) were caught off Majorca Island (western Mediterranean Sea) and examined for parasites. Of the fish sampled, 45% were infected with white and yellow didymozoid capsules and brown nodules, found on the gills and pseudobranchs. Parasite abundance had a strong positive relationship with the fish length; only fish larger than 20 cm were infected, suggesting infection via consumption of an intermediate host, for which E. marginatus size was a limiting factor. The capsules contained two convoluted viable adult trematodes, identified as Didymodiclinus sp., in close contact with host capillary vessels, with no evidence of the tissue inflammatory response. Conversely, nodules containing degraded parasites were surrounded by an intense inflammatory infiltrate. The findings suggest that Didymodiclinus sp. have the potential to evade the host's immune system by inhibiting the inflammatory response.

Describing the spatial patterns of benthic coastal habitats and investigating how those patterns affect the ecology of inhabiting species is a main objective of seascape ecology. Within this emerging discipline spatial scale is a principal topic. Different spatial scales inform on different characteristics of the habitat and therefore the relation between species and their habitats would be better defined when observed at multiple levels of spatial scale. Here we apply a multiscale seascape approach to investigate the habitat preferences of juvenile and adult individuals of dusky grouper (Epinephelus marginatus) in a Mediterranean marine protected area. Results show that the information obtained at different spatial scales is complementary, improving our capability to identify the preferred habitats and how it changes throughout ontogeny. These results show the relevance of implementing multiscale seascape ecology approaches to investigate the species-habitat relationships and to improve management and conservation of necto-benthic endangered top predators.

The dusky grouper Epinephelus marginatus is a protogynous hermaphrodite fish, that maintains high levels of plasma steroids as juveniles, as substrates for sex inversion. These fish are exposed to marine pollution from oil spills during cargo handling. Polycyclic aromatic hydrocarbons (PAHs), such as phenanthrene (Phe), are the main crude oil components and are toxic to fish, acting as endocrine disruptors (ED). This is the first study that investigated impacts of Phe as an ED in E. marginatus juveniles. An in vivo sublethal exposure (96 h) to Phe was carried out at two concentrations (0.1 mg/L and 1 mg/L); exposure to the vehicle (ethanol; ETOH) was also performed. Plasma levels of 17β-estradiol (E2), testosterone (T) and 11-ketotestosterone (11-KT) were measured by ELISA. Gonads, liver and spleen were processed for histological analysis. In an in vitro bioassay, gonad fragments were incubated with Phe (8.91 mg/L) or ETOH. Steroid levels in the culture media were measured by ELISA. The in vivo exposure to Phe triggered an increase of the area of the hepatocytes, increased number of melanomacrophagic centers and hemosiderosis in the spleen; ETOH induced similar effects on spleen. E2 and T levels did not change in plasma or in vitro media. In plasma, ETOH decreased 11-KT levels. Phenanthrene sharply reduced 11-KT levels in vitro. Although in vivo bioassay results were not unequivocal owing to ethanol effects, Phe might disrupt steroidogenesis in juvenile grouper, possibly causing dysfunctions during sex change and gonadal maturity, considering the importance of 11-KT in developing ovaries. Fil: de Campos, Mariana Frias. Universidade de Sao Paulo; Brasil Fil: Lo Nostro, Fabiana Laura. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Biodiversidad y Biología Experimental y Aplicada. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Biodiversidad y Biología Experimental y Aplicada; Argentina. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Biodiversidad y Biología Experimental. Laboratorio de Ecotoxicología Acuática; Argentina Fil: Da Cuña, Rodrigo Hernán. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Biodiversidad y Biología Experimental y Aplicada. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Biodiversidad y Biología Experimental y Aplicada; Argentina. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Biodiversidad y Biología Experimental. Laboratorio de Ecotoxicología Acuática; Argentina Fil: Moreira, Renata Guimarães. Universidade de Sao Paulo; Brasil

WOS: 000434384800027, A new species of caligid copepod, Lepeophtheirus azoricus n. sp., is described from the dusky grouper, Epinephelus marginatus (Lowe), caught in Atlantic waters off Faial Island in the Azores. Both sexes of the parasite were collected from the body surface of the host by the application of osmotic shock. The new species can be distinguished from its congeners by the following set of characters: (1) an obvious conical projection on the posterolateral corners of the genital complex, (2) the relative lengths of the second and third spines on the terminal exopodal segment of leg 4, (3) the relative lengths of the setal elements on legs 5 and 6 of the male, (4) the ornamentation, and lack of a myxal process, on the proximal segment of the maxilliped in both sexes, (5) the unusual structure of the male antenna., Flying Sharks-Collections, Consulting, Conservation and Education, This study was partially supported by Flying Sharks-Collections, Consulting, Conservation and Education.

Summary The aim of this work was to determine the seasonality of nutrient profiles of dusky grouper (Epinephelus marginatus Lowe, 1834) cultured in a cage to improve knowledge on its nutritional composition. Fish (n = 735) were reared in a circular polyethylene floating cage for a 19-month experimental period and provided a commercial pelleted feed once a day with a total daily ration of 1% wet body weight. Fish were sampled every 3–4 months, and biometric parameters as well as muscle composition were determined. The edible proportion of fish increased slightly with culture time. The flesh showed low lipid content, similar to those reported for wild grouper. Biometric indices, muscle proximate composition and fatty acid profiles were significantly affected by seasonality, that is lipids and monounsaturated fatty acids increased during summer, in parallel with the decline of polyunsaturated fatty acids.