Buccal apparatus and gastrointestinal tract dimensions associated to the diet of early life stages of Centropomus undecimalis (Centropomidae, Actinopterygii)

The present study aims to compare the buccal apparatus and gastrointestinal tract of early life stages of Centropomus undecimalis (Bloch, 1792), and relate them to its diet. A total of 190 individuals collected with a channel net in the Catuama estuary (07º40'9.9''S, 34º50'36.7''W), northern coast of the state of Pernambuco, were examined. Morphometrical and meristic data were analyzed for the two initial developmental periods (larval and juvenile). Their digestive tube was morphologically characterized and its content identified. The longest transverse axis of food items was measured, and compared to the standard length (SL) and mouth gape size (D) of the individuals. Body measurement regressions differed significantly (p<0.001) between larvae and juveniles. The stomachs with food content (n=118 individuals) presented a proportion of 62% full and 30% empty (being 8% damaged). They differed in relation to the fullness level and presented a coiled shape when empty. The number of food items in relation to SL and D did not present an evident correlation. Larvae (SL<10 mm) feed on small copepods, while juveniles (SL=11.1 to 64.7 mm) ingest larvae of various decapod species, showing a distinct diet between these initial developmental stages.

Acanthocollaritrema umbilicatum Travassos, Freitas & Bührnheim, 1965 (Digenea: Acanthocollaritrematidae) from the Common Snook, Centropomus undecimalis, from Itamaracá, State of Pernambuco, Brazil

Acanthocollaritrema umbilicatum Travassos, Freitas and Bührnheim, 1965, is the only species of Acanthocollaritrematidae described up to the moment. The systematic position of this species and the validity of the family has been questioned by the possible presence of a gonotyl and a genital atrium associated to the acetabulum. In this paper, specimens of this trematode, collected from Centropomus undecimalis cultivated at Itamaracá, State of Pernambuco, northeast Brazil, were studied under optical and scanning electron microscopy, and compared with available sintypes. Gonotyl and genital atrium were not observed and both family and species are considered valid taxonomic entities. A. umbilicatum is redescribed with the adition of new morphological information.

A new species of Acantholochus (Copepoda: Bomolochidae) parasitic on Centropomus undecimalis (Osteichthyes: Centropomidae) from the coastal zone of the State of Rio de Janeiro, Brazil

A new species of Acantholochus Cressey, 1984 (Copepoda: Bomolochidae) parasitic on the gills of common snook, Centropomus undecimalis, from the coastal zone of the State of Rio de Janeiro, Brazil, is described and illustrated. The new species differs from all other species of Acantholochus by the presence of only one inner seta on middle segment of the second and third endopods.

Ross Boucek holding a common snook (Centropomus undecimalis)

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Common snook (Centropomus undecimalis)

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Common snook (Centropomus undecimalis)

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Influência da densidade de estocagem no cultivo de juvenis de robalo-flecha mantidos em laboratório

O objetivo deste trabalho foi analisar a influência da densidade de estocagem no crescimento, conversão alimentar e sobrevivência de juvenis de robalo-flecha (Centropomus undecimalis). Os peixes foram coletados em ambiente natural e treinados a aceitar dietas artificiais. Os indivíduos, com comprimento total de 13±0,4 cm e peso de 23±0,3 g foram estocados em tanques circulares de fibra de vidro de 5 m³, com água do mar e aeração contínua, nas densidades de 3, 6 e 9 peixes/m³, por 180 dias. Os valores de amônia total (0 a 0,5 mg/L), temperatura da água (23,3 a 30,6ºC), salinidade (17 a 34 g/L), pH (7,8 a 8,4) e oxigênio dissolvido (4,8 a 6,9 mg/L) apresentaram padrão similar entre os tratamentos. A conversão alimentar (1,88, 2,06 e 2,31) e a sobrevivência (100%, 98,9% e 96,3%) foram significativamente melhores nos tratamentos com 3 e 6 peixes/m³. As médias finais de peso (110, 87 e 80 g) e comprimento total (20, 18,5 e 18 cm) apresentaram diferença significativa. A maior taxa de crescimento foi observada com 3 peixes/m³; entre as demais não houve diferença. Entretanto, a biomassa final (332, 511 e 703 g/m³) foi diretamente proporcional à densidade. A baixa densidade favorece o cultivo do robalo em relação ao crescimento, sobrevivência e conversão alimentar.

Eugenol as an anesthetic for juvenile common snook

The objective of this work was to evaluate the efficacy of eugenol as an anesthetic for juvenile common snook, and to determine the minimum effective concentration for use in handling procedures. In the first trial, juvenile common snook were subjected to immersion baths at 25, 50, 75, 100, 125, and 150 mg L-1 eugenol concentrations, after which induction and recovery times were evaluated. In the second experiment, the lethal exposure time (LT50) at 75 mg L-1 was estimated. Minimum effective eugenol concentration was 50 mg L-1, andthe stage of deep anesthesia and recovery were, respectively, reached at 126.3 and 208.8 s. At 75 mg L-1, LT50 was 1,314 s, and induction time and recovery were also satisfactory; however, fish cannot tolerate over 229 s exposure.

Common snook fed in alternate and continuous regimens with diet supplemented with Bacillus subtilis probiotic

The objective of this work was to evaluate the addition of Bacillus subtilis probiotic to the feed of common snook (Centropomus undecimalis) fingerlings, in alternate and continuous regimens. Six hundred and sixty fish, with average length of 5.90±0.88 cm and weight of 1.92±0.28 g, were stocked in 12 cages of 1.0 m3, with 55 fish each. The experimental design was completely randomized, with three treatments and four replicates. The treatments consisted of diet with the addition of probiotic, provided in alternate regimen for 7 days and in continuous regimen; besides a control without probiotic in the feed. Zootechnical performance, body composition, immune response, and blood parameters were evaluated. No significant differences were observed in zootechnical performance indexes and in body composition of fish treated with probiotic, when compared to the control. Fish from the alternate regimen showed an increment in respiratory burst and a lower total erythrocyte count than fish from the continuous regimen and the control. Fish from the continuous regimen did not differ from those of the control. The addition of Bacillus subtilis does not increase growth rates of common snook fingerlings; however, it has an immunostimulant action when supplied in alternate regimen.

Biodiversidade e abundância da ictiofauna associada ao cultivo orgânico de Litopenaeus vannamei (Boone, 1931)

The expansion of shrimp farming has caused a series of environmental impacts, often as a result of lack of planning and adequate management. Organic aquaculture has emerged as an alternative to conventional shrimp farming, and differently, aims at the economical, ecological and farming potential of other organisms, such as fishes, oysters and seaweeds. The present study aimed at evaluating the biological diversity and abundance of the ichthyofauna associated to Litopenaeus vannamei organic culture at PRIMAR farm (Rio Grande do Norte, Brazil). The sampling period consisted of four culture cycles (1, 2, 3, and 4) accomplished in four grow-out ponds (V1, V7, V2, and V4) in 2005. The first two culture cycles were carried out during the rainy season, and the last two cycles, during the dry season. Environmental (temperature, salinity, transparency, and rainfall), biodiversity (diversity and uniformity and abundance indexes) of the ichthyofauna, and shrimp productivity data were collected throughout these four culture cycles. The results obtained for the environmental variables showed that both salinity and transparency oscillated in a significant way (p < 0.001) between culture cycles. In relation to the abundance of the ichthyofauna, fifty four species associated to the organic culture of Litopenaeus vannamei were collected and identified at PRIMAR. For the biodiversity criterion, larger species richness (S = 46) and uniformity (E = 0.59 ± 0.16) were observed during cycles 3 and 4 than in cycles 1 and 2 (S = 41 and E = 0.15 ± 0.12). A positive and significant correlation was obtained for the transparency with diversity and uniformity of fish species between cycles 1 and 2 (wet season) and cycles 3 and 4 (dry season) (p < 0.017 - Shannon Index; p < 0.008 - Pielou Index, respectively). A correlation could not be established between shrimp productivity and fish biomass. However, fish biomass decreased from cycles 1 and 2 to cycles 3 and 4, concomitant with an increase in shrimp productivity, most probably due to a higher (from 58.0% to 71.0%) shrimp survival. Regarding the culture potential of the ichthyofauna, three species (Mugil curema, Mugil liza and Chaetodipterus faber) were identified as potential farming alternatives, either singly or in consortium with Litopenaeus vannamei. A fourth species (Centropomus undecimalis) was indicated as an alternative for single culture or in consortium with other fish species. In conclusion, the large diversity of estuarine fishes associated to Litopenaeus vannamei farming observed at PRIMAR clearly indicated the ecological feasibility for organic aquaculture in northeastern Brazil

Territorialidade e pesca: atualidades e tradições no uso dos recursos pesqueiros na comunidade litorânea da praia da Pipa Rio Grande do Norte

The need for sustainability in the exploitation of natural resources in coastal areas has been out in recent years, as well as the social and cultural sustainability of traditional communities in these regions. Coastal and estuarine wild areas are influenced directly or indirectly by a set of human activities such as artisanal fishing. Therefore, there is a demand for an integrated design of these areas and according to the landing values, a pattern of unsustainable development of national marine fishing activity. The study was conducted in the coastal community of Praia da Pipa, Tibau do Sul municipality, RN, between june 2009 and june 2010 and aimed to characterize the fishery performed, its socio-economic strategies and fishing areas, as well as to identify ichthyofauna, to assess the sustainability of the major resources and to identify cultural traits related to artisanal fisheries, their problems and prospects; linking tradition and the present fishing activity carried out in the community. For this study, a total of 67 structured interviews were collected, including qualitative and quantitative data. A total of 133 fish landings and direct observations were performed. Informants were identified according to one of the following categories: fishermen, vessel masters and members of the local population with offspring. Applications SPSS 10.0, Paint.Ink and Microsoft Office Excel 2007 were used for tabulation and analysis of results. Local fishermen are, on average, 25 years fishing, have 40 years old and the average monthly income is up to 03 minimum wages. The local fleet consists of 20 vessels, that uses different line sizes and types of networks, operating in 21 fishing grounds and showing a reduction in the vessel numbers by 66% in the last decade. We recorded 76 species of fish, captured by the local fleet and the top 5 were quantitatively analyzed serra spanish mackarel (Scomberomorus brasiliensis), little tunny (Euthynnus alleteratus), yellowtail snapper (Ocyurus chrysurus), red snapper (Lutjanus analis) and common snook (Centropomus undecimalis), accounting for 46,5% of production in the period. The capture of these species was composed mostly of adults. Data analysis showed a significant decrease of the local fishing activity over the last decade due to the weakness displayed by the political-social category, the devaluation of local knowledge and the emergence of new sources of income through increased tourism. The characteristics of the fishing community suggest it to pass through significant changes as the appreciation of their cultural and traditional aspects. We identified a tendency to sustainability of main species caught, suggesting that public policies to be adopted locally comply with the current characteristics of fishing undertaken in the community and knowledge of fishermen related to the environment, allowing environmental, as well as social and cultural sustainability of the community involved.

Caracterização morfológica e bioquímica do sistema digestório e identificação por isótopos estáveis de robalo peva e flexa selvagens e de cativeiro

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Dollar Sunfish (Lepomis marginatus)

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Green tree frog

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Spotted tilapia (Tilapia mariae)

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