Description of diet of pelagic fish in the southwestern Atlantic, Brazil

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

5S rDNA chromosomal mapping and COI sequence analysis reveal differentiation among distinct populations of a characid fish Serrapinnus notomelas

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Estudo da diversidade de Sardinella brasiliensis (Steindachner, 1879), na área entre Macaé (22º23'S) e Ilha de Santa Catarina (27º35'S): 1. Crescimento de dimensões corporais

The growth of body proportions of Sardinella brasiliensis was not homogeneous in the study area, between Macaé (RJ) and Santa Catarina Island (SC); the growth rates (K) of the von Bertalanffy growth curve were greater than growth rates for another áreas. In this area the biomass estimates for pelagic fish is poor, and near Cabo Frio occurs an upwelling zone. These facts permit the sardines to attain large lengths in this area. Between Rio de Janeiro and Florianópolis the growth rates were lower than in the northern part and Paranaguá Bay. on the other hand the biomass estimates for pelagic fish in Rio de Janeiro-Florianópolis region was very high, and in this zone the population density is high and the growth rates are small. Paranaguá Bay is a particular region because of its geographical and oceanographic conditons; this is a shelter region with different features and the sardines living there attain small length. In this area the growth rates are intermediary among growth rates for fishes from Macaé-Cabo Frio and Rio de Janeiro-Florianópolis regions. Therefore, the growth rates for sardines in southeast Brazilian proves to be dependent of the population density, food and oceanographic conditions.

The hydraulic management of the Barra Bonita reservoir (SP, Brazil) as a factor influencing the temporal succession of its fish community

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Importance of lateral lagoons for the ichthyofauna in a large tropical reservoir

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Ictiofauna de lagoas marginais sazonalmente isoladas, rio Turvo, bacia do rio Grande, Alto Paraná, SP

Pós-graduação em Aquicultura - FCAV

Interações tróficas entre espécies pelágicas do Atlântico Sudoeste: utilizando isótopos estáveis e inferência bayesiana

Pós-graduação em Ciências Biológicas (Zoologia) - IBRC

Feeding, body condition and reproductive investment of Astyanax intermedius (Characiformes, Characidae) in relation to rainfall and temperature in a Brazilian Atlantic Forest stream

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Surface-spreading technique of meiotic cells and immunodetection of synaptonemal complex proteins in teleostean fishes

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Extensive spreading of interstitial telomeric sites on the chromosomes of Characidium (Teleostei, Characiformes)

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Five new records of Luvarus imperialis (Acanthuroidei: Luvaridae) in the south-west Atlantic Ocean

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Differences in the ichthyofauna feeding habits among lateral lagoons and the river channel in a large reservoir

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Effects of a small fish cage farm on zooplankton assemblages (Cladocera and Copepoda: Crustacea) in a sub-tropicalreservoir (SE Brazil).

In Brazil, the environmental impacts of fish cage farming in water reservoirs have not been well studied. As this activity is being increasingly practiced, investigations on the impacts of this practice are strongly needed. The goal of this study was to investigate the effects of a small cage tilapia farm on zooplankton assemblages in an oligo/mesotrophic reservoir (Jurumirim Reservoir, Paranapanema River). Zooplankton, limnological variables, and water samples were obtained trimonthly during a year at two sample sites, one was located adjacent to the cage farm and the control area was located one kilometer away from it. Eighteen species were identified and Cladocera was the dominant group. The same species of microcrustaceans were identified at both sites. Among the ecological attributes studied, only evenness showed a tendency towards being higher in the control site. Significant differences between studied variables in the sites were observed only for material in suspension. The results of the study indicate that, during the studied period, the cage farm did not generate detectable changes in the zooplankton assemblages and their ecological attributes. However, small differences in some limnological variables could be an indication of some environmental changes associated with the fish farm system.

Predation on microcrustaceans in evidence: the role of chaoborid larvae and fish in two shallow and small Neotropical reservoirs

This study was focused on the predation upon microcrustaceans by an invertebrate predator (chaoborid larvae), and vertebrate predators (fish), in two small reservoirs in southeastern Brazil, with and without macrophytes, in two climatic periods (dry and rainy seasons). Chaoborus larvae were sampled in the limnetic zone, as they are scarce in the littoral, and fish in both limnetic and littoral zones. Their diets were evaluated by the analysis of the crop (chaoborid) or stomach contents (fish). Chaoborid larvae consumed the dinoflagellate Peridinium sp. or other algae, rotifers, and planktonic microcrustaceans. The fish species that included microcrustaceans in their diets were juveniles caught in the littoral. Aquatic insects, plant fragments, and detritus were their major dietary items, microcrustaceans representing a minor item. Planktonic copepods contributed more to the diet of chaoborid larvae than planktonic cladocerans. Fish preyed on planktonic microcrustaceans, as well as on benthic and macrophyte-associated species. Microcrustaceans were not heavily preyed on by chaoborid larvae and fish in both reservoirs.

Isolation and characterization of Flavobacterium columnare (Bernardet et al. 2002) from four tropical fish species in Brazil

Flavobacterium columnare é o agente etiológico da columnariose em peixes de água doce, ocasionando enfermidade na pele e nas brânquias, provocando freqüentemente um grande número de mortalidade. O objetivo deste estudo foi o isolamento e a caracterização de Flavobacterium columnare em peixes tropicais no Brasil. Piracanjuba (Brycon orbignyanus), pacu (Piaractus mesopotamicus), tambaqui (Colossoma macropomum) e cascudo (Hypostomus plecostomus) foram examinados externamente com relação a sinais característicos de columnariose, como manchas acinzentadas na cabeça, região dorsal e pedúnculo caudal dos peixes. A amostragem compreendeu a coleta de 50 exemplares de peixes, representando as quatro diferentes espécies escolhidas para este estudo. Amostras para o isolamento foram obtidas através de raspado com swab estéril das lesões e do rim dos peixes clinicamente diagnosticados como acometidos por columnarios e imediatamente semeados em meios de culturas artificiais (líquido e sólido) próprios para o estudo de Flavobacterium segundo Carlson e Pacha (1968). No meio líquido, houve o desenvolvimento de microrganismos que observados em gota pendente apresentaram a forma de bacilos finos, longos, móveis por deslizamento. Através da coloração de Gram, apresentaram morfologia de bacilos finos, Gram negativos, agrupados em colunas. em meio sólido, as colônias eram pequenas, cinza-amareladas, com borda em forma de raiz. No total, foram obtidos quatro isolamentos: 01 cepa de Brycon orbignyanus; 01 cepa de Piaractus mesopotamicus; 01 cepa de Colossoma macropomum; e 01 cepa de Hypostomus plecostomus. A caracterização bioquímica das amostras, como absorção do vermelho Congo, produção de flexirrubina, produção de H2S e redução do nitrato, sugere que os isolamentos poderiam ser classificados como Flavobacterium columnare.