Habitat use and abundance of goliath grouper Epinephelus itajara in Brazil: a participative survey

Developing survey strategies for threatened species is often limited by access to sufficient individuals to acquire information needed to design appropriate conservation measures. The goliath grouper (Epinephelus itajara) is a large reef fish, globally classified as critically endangered. In Brazil, fishing has been prohibited since 2002. Herein we investigated habitat use and abundance of E. itajara in Brazil drawn from a participative survey, which engaged volunteer divers in data-collection. A total of 188 reports were recorded between 2005 to 2011 throughout 13 Brazilian states. Our results revealed that habitat type influenced the relationship between total length and depth of occurrence of E. itajara. We observed a significant difference between habitats, artificial presented a nonlinear and natural an asymptotic relationship. This study underscores the importance of developing conservation measures addressing specific habitats and locations to enhance population recovery. Artificial structures (shipwrecks and manmade reefs) are critical habitats that must be considered as highly sensitive areas to E. itajara strategic conservation policies. We suggest the creation and implementation of marine protected areas, as key strategies for E. itajara conservation, especially for artificial habitats and aggregation sites124803810O desenvolvimento de estratégias de pesquisa para espécies ameaçadas é frequentemente limitado pelo acesso a indivíduos suficientes para adquirir informações necessárias para elaborar medidas de conservação adequadas. Dentre essas espécies, o mero (Epinephelus itajara) é um peixe recifal de grande tamanho, classificado globalmente como criticamente ameaçado. No Brasil, a pesca é proibida desde 2002. Investigou-se o uso de hábitat e abundância de E. itajara no Brasil através de uma pesquisa participativa, que engajou mergulhadores voluntários na coleta dos dados. Um total de 188 relatos foram registrados entre 2005 a 2011 em 13 estados brasileiros. Os resultados revelaram que o tipo de hábitat influenciou a relação entre o comprimento total e profundidade de ocorrência de E. itajara. Observou-se uma diferença significativa entre hábitats: hábitat artificial apresentou uma relação não linear e hábitat natural uma relação assintótica. Este estudo ressalta a importância do desenvolvimento de medidas de conservação abordando hábitats e locais específicos visando a recuperação populacional. Estruturas artificiais (naufrágios e recifes feitos pelo homem) são hábitats críticos que devem ser considerados como áreas relevantes para as estratégias políticas conservação de E. itajara. Sugere-se a criação e implementação de áreas marinhas protegidas como uma estratégia fundamental para a conservação de E. itajara, especialmente em hábitats artificiais e locais de agregaçãosem informaçã

Peixes de Costão Rochoso de Santa Catarina. I. Arvoredo

Este livro representa um passo importante no sentido de ampliar o conhecimento acerca da ictiofauna marinha do sul do Brasil e de sensibilizar pesquisadores, tomadores de decisão e o público em geral com relação à importância da conservação da Reserva Biológica Marinha do Arvoredo.ABSTRACT: The book is timely, as it provides meaningful support to regional management strategies, where the costal zone is in demonstrable irregular overgrowth. Although not specifically meant for management applications, the check list presented, as well as the photo-drawing guide is of great utility for many ecology/community studies. The book synthesizes a 10-year research effort, and is organized in several topics, which includes an introduction about the ABMR, a synopses on reef fish ecology biological adaptations of reef fish, systematic and rocky-shore habitat occupation. A check list and menaced species are also pointed out, as well as an explanation of how-to-use the guide, glossary and index. A total of 84 species are presented in colour underwater photos, common names are given in Portuguese, Spanish and English, with a detailed description of the most important distinctive features, pointed in schematic drawings of each species; behavior, feeding habits, reaction to divers and distribution are also reported. The book is a strong tool to accurately identifying the most common observed fish species when diving along South Brazil. This guide-book can surely be widely used in Brazil, especially to introduce young scientists and the general public in the rocky-shore fish ecology. Scuba divers will also benefit from this tool, which provides a practical way for further studying and identifying fishes

Normally anomalous otoliths in adults of reef croaker, Odontoscion dentex

Odontoscion dentex is reef fish (Sciaenidae) commonly found in the coastal shallow waters of Florida (US) until Santa Catarina (BR). Sciaenids, in general, are highly acoustic fish, both producing and receiving water vibrations through the lateral line system. As consequence they have large and irregular otoliths, associated to a well-developed lateral line and swimbladder. Several irregularities have been observed in fish sagittal otoliths, but mainly restricted to the replacement of the mineral form, i.e. aragonite by vaterite, in the carbonate matrix. This is usually recorded in rockfishes, including one scianidae species. However, these structures have been assumed to be anomalous and occasional in some individuals. In sagittae of O. dentex a permanent structure was however recorded, as a deep hole near the otolith’s core, usually with a U-shape. This irregularity was observed in all specimens analyzed, in both optic and scanning electron microscopy images, during the grinding and polishing procedures, after embedding the otolith in epoxy resin, for ageing purposes. Our result suggests that this is a non-artifact and permanent structure observed in O. dentex sagittal otoliths, which biological meaning is, at present, unknown

Feeding ecology and trophic ontogeny in Epinephelus marginatus (Perciformes: Serranidae) from south Brazil

Copyright © 2008 Société Française d’Ichtyologie.The stomach contents of 257 specimens of Epinephelus marginatus (197-920 mm TL) obtained between February 1999 and December 2003 in Santa Catarina State (South Brazil) were investigated in order to analyse their diet composition and understand the feeding strategy and interspecific diet overlap. E. marginatus from south Brazil fed mainly on brachyuran crustaceans, followed respectively by teleost fish and cephalopods. In ontogenetic terms the importance of these groups remains practically the same and the feeding strategy also did not show significant shifts. A generalist strategy with heterogeneous feeding is present in all four size classes and the increase of nutritional requirements during the life cycle is satisfied by predating on larger prey instead of a greater number of preys. Changes in the relative importance of the main prey species and brachyuran prey size-range appear to be an important mechanism to prevent dietary niche overlap in E. marginatus from south Brazil.RÉSUMÉ: Stratégie alimentaire et variations ontogéniques chez Epinephelus marginatus (Serranidae) dans le sud du Brésil. Les estomacs de 257 Epinephelus marginatus (197-920 mm LT) obtenus entre février 1999 et décembre 2003 dans l’État de Santa Catarina (sud du Brésil) ont été étudiés pour en analyser le contenu, pour comprendre la stratégie alimentaire de l’espèce, et pour comparer son alimentation avec celles d’autres espèces. E. marginatus, au sud du Brésil, s’alimente surtout de crustacés brachyoures puis, respectivement, de téléostéens et de céphalopodes. Pendant la croissance, l’importance de ces groupes de proies se maintient de façon similaire dans les quatre classes de taille, sans différence significative. La stratégie généraliste, caractérisée par une alimentation hétérogène, se vérifie pour les quatre classes de taille. L’augmentation des besoins alimentaires avec la taille se traduit par une prédation de proies plus grosses et non par une augmentation du nombre de proies. Des changements dans l’importance relative des proies les plus importantes et dans la taille des brachyoures constituent un mécanisme important de prévention de recouvrement de la niche trophique entre classes de taille au sein de la population d’E. marginatus du sud du Brésil

Feeding ecology and trophic ontogeny in Epinephelus marginatus (Perciformes: Serranidae) from south Brazil

Copyright © 2008 Société Française d’Ichtyologie.The stomach contents of 257 specimens of Epinephelus marginatus (197-920 mm TL) obtained between February 1999 and December 2003 in Santa Catarina State (South Brazil) were investigated in order to analyse their diet composition and understand the feeding strategy and interspecific diet overlap. E. marginatus from south Brazil fed mainly on brachyuran crustaceans, followed respectively by teleost fish and cephalopods. In ontogenetic terms the importance of these groups remains practically the same and the feeding strategy also did not show significant shifts. A generalist strategy with heterogeneous feeding is present in all four size classes and the increase of nutritional requirements during the life cycle is satisfied by predating on larger prey instead of a greater number of preys. Changes in the relative importance of the main prey species and brachyuran prey size-range appear to be an important mechanism to prevent dietary niche overlap in E. marginatus from south Brazil.RÉSUMÉ: Stratégie alimentaire et variations ontogéniques chez Epinephelus marginatus (Serranidae) dans le sud du Brésil. Les estomacs de 257 Epinephelus marginatus (197-920 mm LT) obtenus entre février 1999 et décembre 2003 dans l’État de Santa Catarina (sud du Brésil) ont été étudiés pour en analyser le contenu, pour comprendre la stratégie alimentaire de l’espèce, et pour comparer son alimentation avec celles d’autres espèces. E. marginatus, au sud du Brésil, s’alimente surtout de crustacés brachyoures puis, respectivement, de téléostéens et de céphalopodes. Pendant la croissance, l’importance de ces groupes de proies se maintient de façon similaire dans les quatre classes de taille, sans différence significative. La stratégie généraliste, caractérisée par une alimentation hétérogène, se vérifie pour les quatre classes de taille. L’augmentation des besoins alimentaires avec la taille se traduit par une prédation de proies plus grosses et non par une augmentation du nombre de proies. Des changements dans l’importance relative des proies les plus importantes et dans la taille des brachyoures constituent un mécanisme important de prévention de recouvrement de la niche trophique entre classes de taille au sein de la population d’E. marginatus du sud du Brésil

Rocky reef fish assemblage structure in coastal islands of Southern Brazil

Rocky reef fish assemblage structure in seven coastal islands of Southern Brazil was characterized by underwater visual census (20 m x 2 m transect method 40 m2), average depth of six meters, to obtain density (fish/40 m2) and biomass (grams/40 m2). Fish species were categorized according to their trophic category and geographical distribution. In total, 526 strip transects were performed, covering an area of 21,040 m2, totaling 19,377 individuals (means of 36.83 fish/40 m2 and 1,790.23 g/40 m2), distributed among 73 species from 34 families. Among these, 60% of the species occur in the western Atlantic, 20% are transatlantic and 9.60% occur only in the Brazilian Province. The species Stegastes fuscus was the most frequent and with highest density. Acanthurus chirurgus showed the highest biomass, followed by S. fuscus. Itacolomis Island presented the highest density, 48.18 fish/40 m2, followed by Veado Island with 43 fish/40 m2. Regarding biomass, Itacolomis Island and Pedra da Baleia were the most representative with mean values of 3,253 and 3,028 g/40 m2, respectively. Mobile invertebrate predator was the trophic category with the highest density, represented by 26% of species registered, also having the highest density (12.57 fish/40 m2). Mobile invertebrate showed the highest biomass (780.48 g/40 m2). Our results indicated that despite the similarity in taxonomic composition between islands, there are differences in density and biomass, highlighting singular assemblage structures, whether by environmental and/or anthropogenic factors, and dominated by few species, both in density and biomass

Habitat use and abundance of goliath grouper Epinephelus itajara in Brazil: a participative survey

Developing survey strategies for threatened species is often limited by access to sufficient individuals to acquire information needed to design appropriate conservation measures. The goliath grouper (Epinephelus itajara) is a large reef fish, globally classified as critically endangered. In Brazil, fishing has been prohibited since 2002. Herein we investigated habitat use and abundance of E. itajara in Brazil drawn from a participative survey, which engaged volunteer divers in data-collection. A total of 188 reports were recorded between 2005 to 2011 throughout 13 Brazilian states. Our results revealed that habitat type influenced the relationship between total length and depth of occurrence of E. itajara. We observed a significant difference between habitats, artificial presented a nonlinear and natural an asymptotic relationship. This study underscores the importance of developing conservation measures addressing specific habitats and locations to enhance population recovery. Artificial structures (shipwrecks and manmade reefs) are critical habitats that must be considered as highly sensitive areas to E. itajara strategic conservation policies. We suggest the creation and implementation of marine protected areas, as key strategies for E. itajaraconservation, especially for artificial habitats and aggregation sites