Distribuição e abundância relativa de bagres marinhos (Siluriformes, Ariidae) na Baía de Sepetiba, Rio de Janeiro

Abstract

Marine catfish (Ariidae) are abundant resources in otter trawl fisheries carried out at Sepetiba Bay, Rio de Janeiro (Lat. 22o54, 23o04'S; Long. 43o34 44o10'W). Relative abundance and distribution were assessed, based in 158 fishing sampling at seven sites in the Bay, between July-1993 e June-1996. Five species were recorded in the following abundance rank order: Genidens genidens (Valenciennes, 1839), Caihorops spixii (Agassiz,1829), Sciadeichthys lunisculis (Valenciennes, 1840), Nelunia barba (Lacepede, 1803), and Bagre marinus (Mitchill, 1814), the latter have been caught in only two samples. Marine catfish showed higher abundance in the inner Bay, with indication of spatial segregation. G genidens was abundant in ali sites of lhe inner Bay, C. spixii e N. barba, near to rivers mouths, andS lunisculis, being widespread in ali studied area. Sazonality was not evident, with few exceplions in some of the three annual cycles; G. genidens and S. luniscutis were more abundant in biomass in summer 1994/95 (G. genidens) and 1993/94 (S. luniscutis). G. genidens e N. barba show higher abundance (CPUE and biomass) between July-93 and June-95 and C. spixii e S. luniscutis between July-95 and June-96. Total association index indicates a overall positive association among ali species, with. higher Jaccard and Sorensen similarities coefficient for the pairs C. spixii/G. genidens, G. genidens/S. luniscutis, e C. spixii/S. luniscutis. Pearson linear correlation and Sperman rank indicate that G. genidens and N. barba are inversely correlated to C. spixii and S. luniscutis. Spatial segregation strategy may be explaining the coexistence of the marine catfish at Sepetiba Bay.