15 research outputs found
Temporal patterns in the occurrence of selected tropical fishes in mangrove creeks: implications for the fisheries management in north Brazil
Nycthemeral and Monthly Occupation of the Fish Assemblage on a Sheltered Beach of Baía Norte, Florianópolis, Santa Catarina State, Brazil
Interpreting fish community records is challenging for several reasons, including the lack of past ichthyofauna data, the cyclical temporal variations in the community, and the methodology employed, which usually underestimates fish assemblages. The objective of this study was to describe short-scale and meso-scale (nycthemeral period and months, respectively) temporal variations in the ichthyofauna composition and structure of a sheltered beach of Baía Norte (Florianópolis, Santa Catarina state, Brazil), using a capéchade net. Samples were collected monthly for a period of 48 hours. During the period from December 2010 to November 2011, a total of 19,302 individuals belonging to 89 species and 39 families were captured. The number of individuals that were sampled during the day and/or night was dependent on the sampling month. On average, the daytime assemblage was more abundant and different in structure and composition than the nighttime assemblage. Of the eight species that had the highest Index of Relative Importance (%IRI), five had higher variations (ANOVA F) between the day and night than between the months. This finding reinforced the need for sampling during both the day and night. The capéchade net effectively captured demersal and pelagic individuals in a broad range of sizes
Reproductive biology of Cetengraulis edentulus (Cuvier, 1829), the major fishery resource in Guanabara Bay, Brazil
Analysis of fish assemblages in sectors along a salinity gradient based on species, families and functional groups
ASPECTOS SAZONAIS DE OCORRÊNCIA E TAMANHO DE Xenomelaniris brasiliensis (QUOY & GAIMARD, 1824) (TELEOSTEI, ATHERINIDAE) NA LAGUNA DE PIRATlNINGA, NITERÓI - RJ.
This study covers features of seasonal occurrence, spatial distribution and seasonal structure concerning size of the Xenomelaniris brasilensis in the Laguna de Piratininga, Rio de Janeiro. during the period between February 1990 to January 1992. X. brasiliensis showed a seasonal occurrence in the lagoon with greater abundance in the warmer months. The species was predominant on areas of greater depth and water transparency with abundant underwater vegetation. Adult individuals of the X. brasiliensis could consistently be found during the two years of the study, with clear predominance in the warmer period, while juveniles scareely occurred in cold period.Foram estudados aspectos de ocorrência sazonal, distribuição espacial e estrutura sazonal de tamanho de Xenomelaniris brasilensis na laguna de Piratininga, Niterói-RJ, no período de fevereiro de 1990 a janeiro de 1992. Evidenciou-se clara sazonalidade na ocorrência de X. brasilensis na laguna, sendo mais abundante em meses quentes e em locais mais profunÂdos e de maior transparência da água, com abundância de vegetação submersa. Os indivíduos adultos de X. brasilensis estiveram presentes ao longo dos dois anos de estudo e predominaÂram em período quente, enquanto os jovens ocorrem escassamente em período frio
Sex ratio and sexual dimorphism of the anchovy Anchoa januaria (Actinopterygii, Engraulidae) in a tropical bay in south-eastern Brazil
Distribuição espacial e temporal de Cetengraulis edentulus (Cuvier) (Actinopterygii, Engraulidae) na Baía de Sepetiba, Rio de Janeiro, Brasil Spatial and temporal distribution of Cetengraulis edentulus (Cuvier) (Actinopterygii-Engraulidae) in the Sepetiba Bay, Rio de Janeiro, Brazil
<abstract language="eng">Anchovies are members of the Engraulidae family, characterized to present coastal pelagic habits, concentrating in large schoolings distributed among the continental shelf and semi-closed environment, like bays, where they are target of heavy fisheries. The present study aims to describe spatial and temporal distribution of Cetengraulis edentulous (Cuvier, 1828) in the Sepetiba bay (22º54'-23º04'S, 43º34'-44º10'W) and to assess influences of environmental variables on fish occurrence. A monthly sampling programme was carried out between October 1998 and September 1999, to take both, fish and environmental information on temperature, salinity and depth. Three bay zones were established based on spatial gradient of salinity and depth. Adults C. edentulus were more abundant in the inner bay zone; seasonally, larger size groups (total length > 16 cm) occurred in spring/summer. Significant negative correlations were found between fish abundance and salinity and depth. The close relationship of this species to innermost areas in bays, and the absence of juveniles in sandy beaches, suggest that young-of-the-year use mangrove areas as recruitment sites