Distribution of the ichthyofauna captured by otter-trawl in Guanabara Bay, Rio de Janeiro, Brazil

Abstract

In order to describe the composition and the structure of the fish community and to analyze spatial distribution patterns of the most frequent and abundant groups in Guanabara Bay, Rio de Janeiro, Brazil, thirty-seven trawls were accomplished in September 1997, May 1998, April and August 2000, in four areas along the north-south environmental gradient of the bay. Fifty-six species, belonging to 27 families, were captured. The families Sciaenidae, Ariidae, Haemulidae, Dactylopteridae, and Triglidae in this order, were the most abundant. Habitat partitioning of the most abundant populations was observed along the bay. Ariidae, mostly represented by the marine catfish Genidens genidens, prevailed in the inner areas (I and II), with lower depths and salinities. Sciaenidae, of which the whitemouth croaker Micropogonias furnieri was the most abundant species, prevailed in the central area (III), with higher depths while Haemulidae and Dactylopteridae were more abundant in the outermost area (IV), with less turbid and more saline waters, and the lowest content of organic matter in the sediment. The outer areas (III and IV), under oceanic influence, presented the greatest fish abundances and the highest species richness.