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The Neotropical region hosts 4225 freshwater fish species, ranking first among the world's most diverse regions for freshwater fishes. Our NEOTROPICAL FRESHWATER FISHES data set is the first to produce a large-scale Neotropical freshwater fish inventory, covering the entire Neotropical region from Mexico and the Caribbean in the north to the southern limits in Argentina, Paraguay, Chile, and Uruguay. We compiled 185,787 distribution records, with unique georeferenced coordinates, for the 4225 species, represented by occurrence and abundance data. The number of species for the most numerous orders are as follows: Characiformes (1289), Siluriformes (1384), Cichliformes (354), Cyprinodontiformes (245), and Gymnotiformes (135). The most recorded species was the characid Astyanax fasciatus (4696 records). We registered 116,802 distribution records for native species, compared to 1802 distribution records for nonnative species. The main aim of the NEOTROPICAL FRESHWATER FISHES data set was to make these occurrence and abundance data accessible for international researchers to develop ecological and macroecological studies, from local to regional scales, with focal fish species, families, or orders. We anticipate that the NEOTROPICAL FRESHWATER FISHES data set will be valuable for studies on a wide range of ecological processes, such as trophic cascades, fishery pressure, the effects of habitat loss and fragmentation, and the impacts of species invasion and climate change. There are no copyright restrictions on the data, and please cite this data paper when using the data in publications., (© 2022 The Ecological Society of America.)

The objective of this study was to analyse the feeding habits and trophic interactions between four oceanic predatory fish around the Fernando de Noronha Archipelago (FNA), Brazil, in the western equatorial Atlantic (3.86°S/32.42°W), internationally recognized as an environment of high economic and ecological value. For this purpose, biological samples of yellowfin tuna (Thunnus albacares), wahoo (Acanthocybium solandri), barracuda (Sphyraena barracuda) and dolphinfish (Coryphaena hippurus) were collected for stomach content and stable isotope analysis. Values of the index of relative importance revealed varied diets, with a strong presence of teleost fishes (Diodontidae and Exocoetidae) for all species, with yellowfin tuna having a greater diversity of food items. Despite being generalists/opportunists, the feeding strategy of these predators showed a tendency towards a specialized diet in the use of the available resources around the FNA. They presented a narrow trophic niche width (Levin's index, Bi < 0.6) and low overlap between species, except between barracuda and wahoo (MacArthur and Levin's, R 0  = 0.72). Isotopic compositions had broad values of δ 13 C and δ 15 N, and were significantly different between species. Our results provide information about the four species' trophic organization and suggest that the predators avoid competition by preying on different prey, thus allowing their coexistence., (© 2021 Fisheries Society of the British Isles.)

Morphometric measurements, meristic counts and DNA barcoding identified the presence of a biglip grunt Plectorhinchus macrolepis in the western Atlantic Ocean. As the species is endemic to the tropical eastern Atlantic Ocean and has not previously been reported in the western Atlantic Ocean, we discuss the possible means by which it might have dispersed to the western Atlantic Ocean. Even though this species is not considered established in Paranaguá Bay, we advocate monitoring of possible new individuals and other exotic fish species., (© 2019 The Fisheries Society of the British Isles.)

The pearlside Maurolicus stehmanni is one of the most abundant mesopelagic fishes off south-eastern Brazil and plays a key role in the regional ecosystem. However, its early life history remains poorly understood. This study examined the M. stehmanni early life stages, from eggs to juveniles, including all developmental changes in external morphology. Larvae are simple in morphology and lack specialized larval structures. Notochord flexion begins at ~5.15 mm body length (BL) and larvae ≥5.95 mm BL are flexed. The relative growth of seven measured larval characters (head length, body depth, snout length, eye diameter, pre-dorsal length, pre-ventral length and pre-anal length) have transition points (allometric inflexion points), indicating biphasic growth patterns which are likely related to shifts in habitat use, feeding and behaviour. Larval development is similar to that of other Maurolicus species. The relatively fast development of the fins, photophores, swimbladder and pigmentation suggests a precocious adoption of a micronektonic lifestyle in the mesopelagic environment., (© 2021 Fisheries Society of the British Isles.)

Studies on the feeding ecology of fish are essential for exploring and contrasting trophic interactions and population and community dynamics within and among aquatic ecosystems. In this respect, many different methods have been adopted for the analysis of fish stomach contents. No consensus has, however, been reached for a standardised methodology despite that for several decades there has been an ongoing debate about which methodical approaches that should be preferred. Here, we critically review and scrutinise methods, addressing their strengths and weaknesses and emphasising inherent problems and possible pitfalls in their use. Although our critical assessment reveals that no completely ideal approach exists, appropriate and reliable procedures can be adopted through careful considerations and implementation. In particular, we advocate that different objectives require different methodical approaches and the choice of method should therefore be closely linked to the research questions that are addressed. For a standardisation of methods, we recommend a combination of the relative-fullness and presence-absence methods as the optimal approach for the commonly applied feeding studies addressing relative dietary composition in terms of prey diversity and abundance. Additionally, we recommend the gravimetric method for objectives related to the quantification of food consumption rates and the numerical method for prey selection studies. DNA-based dietary analysis provides a new and promising complementary approach to visual examination of stomach contents, although some technical challenges still exist. The suggested method standardisation facilitates comparisons across species, ecosystems and time and will enhance the applicability and benefits of fish feeding studies in trophic ecology research., (© 2019 The Authors. Journal of Fish Biology published by John Wiley & Sons Ltd on behalf of The Fisheries Society of the British Isles.)

The diets of six shark species, Sphyrna lewini, Sphyrna zygaena, Carcharhinus obscurus, Carcharhinus limbatus, Rhizoprionodon lalandii and Galeocerdo cuvier, were investigated in a subtropical coastal ecosystem of southern Brazil. Stomach content data were obtained to assess foraging niche segregation and ontogenetic shifts in the diets of these sharks. Five of the shark species off the Paraná coast were ichthyophagous, with the exception of S. zygaena, which was teutophagous. With the exception of G. cuvier, which had a generalist diet, the other five species displayed specialization in their feeding. Ontogenetic shifts were observed in C. obscurus and S. lewini with large individuals consuming elasmobranchs. Owing to the diet overlap between C. obscurus and S. lewini, C. obscurus and C. limbatus and R. lalandii and C. limbatus, future studies on the spatial and temporal distributions of these species are needed to understand the extent of competitive interactions. [ABSTRACT FROM AUTHOR]

Brazil currently ranks as the 11th producer and 1st importer of shark meat around the world. Data available from the FAO software FishStatJ along with data from regional sources, such as governmental bulletins, scientific papers, gray literature and internet were revisited to identify the main issues surrounding pelagic shark fisheries, trade and consumption in the largest country in South America. Among the main findings, it was noted that Brazil has not properly collected fishery statistics since 2007, that many species of threatened sharks are freely landed and traded even though it is prohibited by local legislation and/or international recommendations (regional fisheries management organizations). The blue shark ( Prionace glauca ) is the most frequently recorded shark in the official bulletins and is currently a locally targeted species. Additionally, the significant imports of this species from 23 other countries that also provide fins for Asia has drawn attention in recent decades. Regarding consumption, shark is considered to be low-value seafood compared to more common fish, such as groupers and snappers, and most Brazilians actually do not know that they are eating sharks. At present, the proportion of threatened elasmobranchs (in which sharks are included) in Brazil (33%, of 145 species) exceeds the global rate identified for the group (25%), and, until the present moment, no measure related to the management of species has been implemented. As advice, Brazil urgently needs to restructure its fishery information collection systems, management strategies and to tighten sanitary and labeling regulations for the marketing of fish. [ABSTRACT FROM AUTHOR]

Fishes constitute more than half of the vertebrates, inhabiting almost every aquatic habitat of the world and form an inexpensive source of vital nutrients. The depletion of fishery stocks as a result of anthropogenic interferences is evident worldwide and mandates an urgent need to address the cause before rate of loss exceeds the limit. This makes the assessment of various aspects of fish, especially their feeding ecology quite imperative for developing conservation and management strategies. Food forms a vital factor for fishes required chiefly for growth and reproduction in fishes and its qualitative or quantitative variation is influenced by various biotic and abiotic factors. Amongst the various attributes influencing fishes, food and feeding constitute a vital aspect that impacts the growth and general wellbeing of the fish. Feeding ecology of a fish is directly linked to its population dynamics and helps in understanding of various aspects of fish like habitat preference, competition, prey selectivity, energy transfer etc. Under this backdrop the current review was drafted to acquire knowledge about the three major aspects of feeding ecology of fish i.e., analysis of the gut contents, feeding biology and prey selectivity. The analysis of gut contents helps to identify the prey diversity and abundance consumed by a fish. Feeding biology helps to evaluate the acceptability of the prey by depicting the correlation between biology of the fish and its food preferences. Prey selectivity deals with the evaluation of prey choice depicting the reason behind choice of one prey over the other. [ABSTRACT FROM AUTHOR]

The Neotropics harbour the greatest diversity of freshwater fish on Earth. Despite recent advances in characterizing the fish fauna, the total number of species, distributional range, evolution and ecological traits remain uncertain. Thus, we quantify shortfalls in the knowledge of taxonomy (Linnean shortfall), geographic distribution (Wallacean shortfall), evolutionary relationships (Darwinian shortfall) and feeding habits (Raunkiæran shortfall) of Auchenipteridae driftwood catfishes, one of the most representative groups of the Siluriformes family in the Neotropics. We find a steep increase in the historical accumulation of valid species over time, suggesting that 45% of the total number predicted remains to be described. Auchenipterids also remain under‐collected; only 45% of the ecoregions and less than 3% of the one‐degree grid cells covering the Neotropics are reasonably sampled. The topologies of recent phylogenies are more similar to each other than former ones, showing a tendency towards a robust phylogenetic hypothesis for this family. Current knowledge on feeding habits is biased towards a few genera and species and is still expanding with every new published study. Our study highlights specific knowledge gaps that need to be addressed: a considerable number of Auchenipteridae species remain to be described; and most of valid species lack reliable information on their geographic distribution and feeding habitat. It implies that research on fish systematic biology needs to advance and it will require a concerted effort of taxonomists, ecologists and biogeographers to reduce these gaps. [ABSTRACT FROM AUTHOR]

The conservation challenges facing freshwater ecosystems necessitate broadening our science from understanding individual species loss to anticipating multi-faceted changes to biodiversity. In recent decades, the process of biotic homogenization by which regional biotas become more similar through time has attracted considerable attention. Here, we (1) quantified spatial and temporal changes in taxonomic and functional similarity of fish assemblages among Neotropical reservoirs, (2) determined nonnative species contributions to changes in taxonomic and functional composition, and (3) evaluated relationships between the changes in taxonomic and functional similarity among reservoirs. We did so by considering different spatial scales: inter- and intra-ecoregions. At inter-ecoregion scale, reservoir fish assemblages have become taxonomically homogenized over time, whereas functional trait composition has tended to differentiate. At intra-ecoregion scale, we detected both taxonomic and functional differentiation over time. Despite these overall trends, different ecoregions exhibited considerable variation in patterns of fish faunal homogenization and differentiation. We found a moderate positive relationship between changes in mean taxonomic and functional similarity among reservoirs at inter-ecoregion scale, which was no longer evident within ecoregions. In conclusion, this study demonstrates the strong scale-dependence of perceived patterns in homogenization, and further highlights the magnitude of threats to freshwater biodiversity in the Neotropical ecosystems. [ABSTRACT FROM AUTHOR]

Copyright of Biotropica is the property of Wiley-Blackwell 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.)

While environmental alterations have made Homo sapiens the hyperkeystone species of the globe, biotic homogenization initiated a new era, the "Homogenocene." Still, some terrestrial and aquatic ecosystems in South America are considered pristine and wild, which can lead to a general faith that economic progress is consistent with conservation strategies, even without scientific support. We compiled anthropogenic threats to fish biodiversity in a hierarchical meta‐analysis, along with an evidence synthesis of threats related to biological invasions, based on peer‐reviewed research with the aim to represent the actual conservation status of the South American ichthyofauna. We highlighted human‐related threats and synergistic effects of biological invasions, climate change, environmental alterations (e.g., pollution, aquaculture and damming) and fisheries. Considering measures that reinforce novel alien fish (e.g., artificial hybrids or genetically modified) introductions, it became clear why an eventual increase in local or regional species richness is not always beneficial to aquaculture, biodiversity, human well‐being or nature. In fact, citizens in all societal roles, including scientists, should revise their concepts about threats to fish biodiversity. Environmental policies require more than taxonomic diagnostics to achieve conservation goals under an incompatible scenario of a multiplying number of fish species and biotic homogenization. We advocate for countries in South America using science‐based strategies useful to maintain their social and economic growth along with their "remaining nature." We live a crucial moment when the government overlooks threats to biodiversity and uses agribusiness as the most acceptable manner of fuelling the economy. [ABSTRACT FROM AUTHOR]

Copyright of Neotropical Ichthyology is the property of Neotropical Ichthyology 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.)

Most of the world’s fish fauna is suffering from different types of human impacts and new conservation tools are required. The fish diet analysis is a tool that has been used to evaluate degradation processes of aquatic environments, however, few long-term studies are performed by several reasons (e.g., lack of funding, opportunity). Our aim was to test whether the fish gut content from biological collections can be used for comparisons with current data and, consequently, be used as a tool for long-term environmental impact studies. We compared the gut content of fish preserved for fifteen years in a biological collection with recently sampled fish, considering the factors size of the specimen, preservation time and preservation form. We did not find differences in the gut content percentage of preservation between fish size classes and preservation time. However, we found differences between preservation form, in which the fish fixed in formalin kept the digestive content preserved while the fish preserved directly in alcohol did not. Thus, we encourage the use of fish gut content from biological collections fixed in formalin for long-term ecological studies. Our findings may help elucidate some long-term effects of human impacts on fish fauna. [ABSTRACT FROM AUTHOR]

Background: Ecosystem modeling applied to fisheries remains hampered by a lack of local information. Fishers’ knowledge could fill this gap, improving participation in and the management of fisheries. Methodology: The same fishing area was modeled using two approaches: based on fishers’ knowledge and based on scientific information. For the former, the data was collected by interviews through the Delphi methodology, and for the latter, the data was gathered from the literature. Agreement between the attributes generated by the fishers’ knowledge model and scientific model is discussed and explored, aiming to improve data availability, the ecosystem model, and fisheries management. Principal Findings: The ecosystem attributes produced from the fishers’ knowledge model were consistent with the ecosystem attributes produced by the scientific model, and elaborated using only the scientific data from literature. Conclusions/Significance: This study provides evidence that fishers’ knowledge may suitably complement scientific data, and may improve the modeling tools for the research and management of fisheries. [ABSTRACT FROM AUTHOR]

Sixty Centropomus parallelus juveniles were collected in March 2013 in two locations (Tromomó and Guaraguaçu) inside the Paranaguá estuarine complex, southern Brazil. The habitat residency and movement patterns of the individuals were inferred from Sr:Ca ratios and age recorded in the otoliths. Data suggest that the species spawns preferentially in brackish areas mainly from October to January, and that growth rate during the early juvenile stage could be influenced by environmental salinity. Furthermore, the data also show that C. parallelus can occupy diverse salinity habitats and migrate among marine, brackish and freshwater areas within the Paranaguá estuarine complex, showing a high environmental plasticity and adaptation. [ABSTRACT FROM AUTHOR]

Trophic ecology is essential to understand ecosystem functioning and structure and assist biological conservation. Here we investigate, for the first time, the feeding ecology of Aphanius farsicus, a cyprinodontid fish endemic of a single landlocked river basin in central Iran. We sampled monthly a population of this fish species during a year and examined differences in food across seasons, sexes and sizes. Similarly to other cyprinodonts, A. farsicus showed sexual dimorphism and more abundance of females. Size structure and individual condition varied across seasons, with larger fish in spring and better condition in summer and less in winter. We found no empty guts, suggesting that these fish feed all year round due to the warm climate of its native distribution. Farsi toothcarp diet was based on detritus, algae (particularly diatoms, green algae, and cyanobacteria), and small invertebrates. Seasonal variation in diet was more important than variation due to fish size and the Farsi toothcarp consumed more green algae in spring and early summer and more diatoms and insects the rest of the year. Herbivory was considerable, similarly to a few other cyprinodonts, and increased with fish size, particularly because of higher consumption of green algae. As with species composition in diet, season was more important than size in the variation of number, biovolume, mean size, and diversity of prey captured, with higher number, richness and size of prey captured in summer. The ontogenetic diet shift was less marked in this cyprinodont than in many other Aphanius species, probably due to its reduced size and the resource availability of its habitat, but was also shown by size-dependent feeding selectivity for a few invertebrates. [ABSTRACT FROM AUTHOR]

Background: Data derived from studies of fishers' local ecological knowledge (LEK) can be invaluable to the proposal of new studies and more appropriate management strategies. This study analyzed the fisher's LEK about trophic relationships of fishes in the southeastern Brazilian coast, comparing fishers' LEK with scientific knowledge to provide new hypotheses. Methods: The initial contacts with fishers were made through informal visits in their residences, to explain the research goals, meet fishers and their families, check the number of resident fishers and ask for fishers' consent to participate in the research. After this initial contact, fishers were selected to be included in the interviews through the technique of snowball sampling. The fishers indicated by others who attended the criteria to be included in the research were interviewed by using a semi-structured standard questionnaire. Results: There were interviewed 26 artisanal fishers from three communities of the Ilhabela: Jabaquara, Fome and Serraria. The interviewed fishers showed a detailed knowledge about the trophic interactions of the studied coastal fishes, as fishers mentioned 17 food items for these fishes and six fish and three mammals as fish predators. The most mentioned food items were small fish, shrimps and crabs, while the most mentioned predators were large reef fishes. Fishers also mentioned some predators, such as sea otters, that have not been reported by the biological literature and are poorly known. Conclusions: The LEK of the studied fishers showed a high degree of concordance with the scientific literature regarding fish diet. This study evidenced the value of fishers' LEK to improve fisheries research and management, as well as the needy to increase the collaboration among managers, biologists and fishers. [ABSTRACT FROM AUTHOR]

The reproductive tactics of Deuterodon stigmaturus were investigated in this study, testing whether the species presents a seasonal or opportunistic life-history strategy in a high latitude Atlantic Forest stream in Brazil. The relation between the development of anal-fin spinelets (sexually dimorphic structures in characids) and the reproductive period of D. stigmaturus was also investigated. The species displayed a seasonal life-history strategy, with the reproductive period occurring between austral spring and summer. The reproductive period was related to increase in temperature and photoperiod, corroborating several studies that suggest positive relation between seasonal reproduction and abiotic predictability. The data indicated total spawning occurring in January, coinciding with the month of greatest rainfall (historical and in the study year). However, the observation of postovulatory follicles in previous months suggests small spawning before January. The development of spinelets on the anal-fin was the only sexual dimorphic trait between males and females. Contrasting with several other studies, seasonal development of anal-fin spinelets was observed in adult males, following the reproductive period and regressing afterwards. Thus, some characid species probably retain this structure throughout the year and others do not, which may be related to life-history strategy differences. [ABSTRACT FROM AUTHOR]

The reproductive biology and feeding habits of the electric fish Brachyhypopomus gauderio were studied. The species has seasonal reproductive behavior, with breeding occurring during the Southern Hemisphere spring and summer, and having a positive relation with the photoperiod variation. Brachyhypopomus gauderio was defined as a fractional spawner, with low relative fecundity and high first maturation size. Sexual dimorphism was registered, males undergoing hypertrophy of the distal portion of caudal filament. The results on reproductive biology herein obtained are in agreement with data concerning gymnotiforms from Southern Brazil and Uruguay, pointing to an ecological pattern for the species from high latitudes, differing from species with tropical distribution. According to the analysis of the food items, B. gauderio feed mainly on autochthonous insects, likewise the other gymnotiforms previously investigated, leading to conclude that there is no variation on the diet of the species of the order related to climatic conditions or even to habitat of occurrence. [ABSTRACT FROM AUTHOR]

Studies with annual fish diet have shown that the generalist habit is a dominant strategy within this group.Cynopoecilus fulgens(Cyprinodontiformes: Rivulidae) is a restricted range species, endemic to a small area in Southern Brazil, and aspects of its biology and ecology are poorly known. The main goal of the study was to determine the diet ofC. fulgensthroughout its life cycle and compare it with the prey availability in Southern Brazil wetlands. Specifically, we analyzed samples collected in different stages of ontogenetic development (immature and adult fishes) in various year seasons. A total of 52 food items were found in the diet ofC. fulgens, and invertebrates comprised 96.4% of the counts observed. The richness of consumed and available prey changed along with the seasons. The seasonal variation of the consumed prey richness was mainly related to increase in fish size along the annual cycle. Microcrustaceans represented 75.6%, 80.9%, and 68.4% of the consumed prey in autumn, winter and spring, respectively. Prey composition varied with the seasons and it was not correlated to prey availability. Diet selectivity was different among male, female and immature fish. Our study reported the feeding habits ofCynopoecilus fulgensto improve knowledge of the biological and ecological traits of annual killifishes in Southern Brazil wetlands, where more than 90% of the original wetlands have been lost due to agricultural expansion. [ABSTRACT FROM PUBLISHER]

Body size and environmental prey availability are both key factors determining feeding habits of gape-limited fish predators. However, our understanding of their interactive or relative effects is still limited. In this study, we performed quantitative dietary analysis of different body sizes of goby (Gymnogobius isaza) specimens collected from Lake Biwa between 1962 and 2004. First, we report that the diet was composed mainly of zooplankton (cladocerans and copepods) before the 1980s, and thereafter, shifted to zoobenthos (gammarids). This foraging shift coincided with, and thus can be linked to, known historical events in the lake at that time: decrease in zooplankton abundance with the alleviation of eutrophication, increase in fish body size resulting from fish population collapse, and increase in gammarid abundance due to reduced fish predation pressure. Supporting this view, our data analyses revealed how the long-term changes in the diet composition would be co-mediated by changes in fish body size and environmental prey availability. Specifically, while zoobenthos abundance strongly affected the fish diet composition, larger (smaller) fish preferred zoobenthos (zooplankton). Furthermore, the body size effects were stronger than those of prey availability. These results provide the best long-term evidence that fish feeding habits vary over decades with its body size and prey community due to anthropogenic disturbances. [ABSTRACT FROM AUTHOR]

Sexual, ontogenic and temporal effects in the diet of Dasyatis longa were evaluated to determine feeding habits and trophic ecology. Numeric indices and the index of relative importance were applied to establish the feeding strategy of the species. Independence of the diet with respect to sex, dry or rainy season and size was evaluated with contingency tables, correspondence analysis and multivariate analysis (MANOVA). The trophic relationships of D. longa (by sex and size intervals) were determined using Levin's niche breadth index and the Pianka's diet overlap index and their significance was determined by null models. The trophic level for each size interval and the species was also calculated. Dasyatis longa showed a narrow niche breadth feeding mainly on shrimps and fishes and its diet was dependent on size, but not on sex or season. Juvenile individuals (class I) fed on shrimps, sub-adults (class II) on fishes and adults (class III) on stomatopods. Significant overlaps between size classes I and II and classes II and III were found. The trophic level shows D. longa to be a secondary or tertiary consumer. Due to considerable fishing pressures on shrimps, the principal prey of D. longa, it will be important to determine their ability to adapt to changes in prey populations. [ABSTRACT FROM AUTHOR]

The article presents a study of the effectiveness of the ban on the importation of 10 non-native fish species by aquarium stores in Brazil, with consideration on management options. The Federal Normative Instructions No. 202 and No. 203 of 2008 for saltwater and freshwater fish species passed by the Brazilian Institute of Environment and Renewable Natural Resources (IBAMA). It says that the frequency of the non-native species in the aquarium trade endangers aquatic life in Brazil.

Background: Accessing folk knowledge from small-scale fishers is an affordable and reliable approach to understand the dynamic and diversity of shark species worldwide, especially of those eventually caught. In this context, ethnotaxonomy (folk identification and classification) may represent an alternative to support sharks fisheries management, especially in data-poor places. This study aimed to investigate fishing and ethnotaxonomy of the main shark species caught by small-scale fisheries from the coastal waters of the Brazilian Northeast. Methods: Semi-structured and structured interviews were conducted with fishers targeting general aspects of fishing activities and specific topics regarding ethnotaxonomy, capture, and commercialization of sharks. For species identification, an ethnobiological systematic perspective was used to analyze the folk nomenclature and classification criteria. Non-parametric statistical tests were used to verify associations between species caught, fishing gear, and harvest period. Results: Fishers mentioned 73 binomial names, 21 main folk species, and eight synonymies. Some species belonging to the same scientific genus are often named and grouped by the same folk name, with no distinction between species by fishers. Sharks are most landed as bycatch and correspond to less than 5% of the total commercial fisheries in the communities, with socioeconomic value for subsistence consumption and local commercialization. Sharks were said to be mainly caught with hand line and surface long line during the rainy season, while gillnet captures were associated to the dry season. At least three of the species most mentioned by fishers are currently classified as vulnerable and endangered worldwide. Conclusions: Even though landed sharks account for a small proportion of the fishing catches, their biological and life history features place sharks among the most vulnerable organisms globally. Such an ethnobiological approach towards shark identification may contribute to generate basic information on species caught, their frequency in the landings, and how different species belonging to the same genus can be landed and sold together. This type of information can generate subsidies to the development of conservation and management plans for these fishing resources, where knowledge is scarce. [ABSTRACT FROM AUTHOR]

Although white sharks (Carcharodon carcharias) have been considered rare in Atlantic Canada waters, recent sighting records indicate a potentially increasing presence. We combine historical to present sighting data with satellite telemetry tracks of large juvenile and adult white sharks tagged in US (n = 9) and Atlantic Canada waters (n = 17) to show seasonal white shark presence and distribution in Atlantic Canada, returns by individuals over multiple years, and high site fidelity to the region. Telemetry data indicate that white sharks are a more common and consistent occurrence in Canadian waters than previously thought, presenting two potential scenarios: (i) tagging technology is revealing white shark presence that was historically cryptic and (or) (ii) a northward range expansion of white sharks in the Northwest Atlantic, potentially due to climate change, population recovery, and (or) increasing pinniped prey. Given combined sighting and telemetry data indicate a current need for proactive management of white sharks in Atlantic Canada waters, we propose the basis for a management action plan, addressing conservation priorities, management goals, and research incentives while considering the potential for humanshark interactions. Bien que les grands requins blancs (Carcharodon carcharias) aient ete consideres comme etant rares dans les eaux du Canada atlantique, des signalements recents pourraient indiquer une augmentation de leur presence. Nous combinons des donnees passees et actuelles sur les signalements aux parcours obtenus par telemetrie satellitaire de grands requins blancs adultes et juveniles de grande taille marques dans les eaux des Etats-Unis (n = 9) et du Canada atlantique (n = 17), afin d'etablir la presence et la repartition saisonnieres des grands requins blancs au Canada atlantique, les retours d'individus sur plusieurs annees et leur fidelite au site dans cette region. Les donnees de telemetrie indiquent que les grands requins blancs sont plus repandus et leur presence est plus reguliere dans les eaux canadiennes que ce qui etait presume auparavant, ce qui suggere deux scenarios possibles, a savoir (i) que la technologie d'etiquetage fait ressortir une presence de grands requins blancs qui demeurait cryptique par le passe et (ou) (ii) que leur aire de repartition dans l'ocean Atlantique Nord-Ouest connait une expansion vers le nord, possiblement due aux changements climatiques, au retablissement de la population et (ou) a l'augmentation de proies pinnipedes. Etant donne que les donnees sur les signalements et les donnees de telemetrie combinees font ressortir la necessite d'une gestion proactive des grands requins blancs dans les eaux du Canada atlantique, nous proposons les fondements d'un plan de gestion qui abordent les priorites en matiere de conservation, les objectifs de gestion et les mesures incitatives pour la recherche, tout en tenant compte du potentiel d'interactions humains-requins. [Traduit par la Redaction], Introduction The distribution and abundance of species are rarely static, but fluctuate through time and space in response to the stochasticity of ecological and environmental conditions and anthropogenic influences (Brown [...]

Several Finnish populations of salmonids have been maintained exclusively by stocking hatchery-reared fish for several generations, and it is crucial to know whether domestication has affected fitness-related traits and to assess how the developmental environment influences fish phenotypes. Here, we focused on Lake Saimaa landlocked salmon (Salmo salar m. sebago) and studied the role of the early rearing environment in trait formation by comparing juveniles (fingerlings) from three backgrounds: (i) semi-wild (stocked as alevins), (ii) standard hatchery, and (iii) enriched hatchery conditions We compared juvenile morphology, swimming performance, and capability of feeding on natural prey in early winter. We found no differences between standard and enriched hatchery conditions. Semi-wild fish consumed more prey items, but wet mass of stomach contents did not differ among backgrounds. Swimming endurance was comparable among backgrounds. Semi-wild fish had slenderer body shape and longer fins than hatchery-reared fish. The lack of performance differences between hatchery juveniles and their semi-wild conspecifics is possibly due to reduced phenotypic plasticity caused by extremely low levels of genetic diversity in this population. Comme plusieurs populations finlandaises de salmonides ont ete maintenues exclusivement grace a l'ensemencement de poissons eleves en ecloserie pendant plusieurs generations, il importe de savoir si la domestication a eu une incidence sur des caracteres associes a l'aptitude et d'evaluer l'influence du milieu de developpement sur les phenotypes des poissons. Nous nous penchons sur les saumons d'eaux interieures du lac Saimaa (Salmo salar m. sebago) et etudions le role du milieu de l'elevage precoce dans la formation de caracteres en comparant de jeunes saumons (alevins d'un an) de trois origines distinctes, a savoir (i) des individus semi-sauvages (alevins vesicules au moment de l'ensemencement), (ii) eleves en ecloserie dans des conditions normales et (iii) eleves en ecloserie dans des conditions enrichies. Nous comparons la morphologie des jeunes saumons, leur performance de nage et leur capacite a se nourrir de proies naturelles au debut de l'hiver. Nous ne relevons aucune difference entre les individus issus d'ecloseries dans des conditions normales et enrichies. Les poissons semi-sauvages consomment un plus grand nombre de proies, mais la masse humide des contenus stomacaux ne varie pas selon l'origine des poissons. Les poissons semi-sauvages ont des corps plus elances et des nageoires plus longues que les poissons eleves en ecloserie. L'absence de differences sur le plan de la performance entre les jeunes poissons issus d'ecloseries et leurs congeneres semi-sauvages est possiblement due a une plasticite phenotypique reduite causee par des degres extremement faibles de diversite genetique dans cette population. [Traduit par la Redaction], Introduction Many natural salmonid populations are threatened by various human activities, such as overharvesting and construction of hydropower dams. Dams often severely block the movements of migratory fishes and thus [...]