Spatial variation of catfish (Siluriformes, Ariidae) collected in the “Baía da Ribeira” bay, Angra dos Reis, Rio de Janeiro, Brazil and probable influences of temperature and salinity

Abstract

The present research aims at studying the spatial variation of catfish collected in the Baía da Ribeira, Angra dos Reis, Rio de Janeiro, Brazil. The area was divided into five sampling sites, being sites 1, 2 and 3 located at the inner part and stations 4 and 5 at the outer part of the bay. Samples were carried out from January 2002 to November 2006. Fish were collected by an otter trawl net. Captured fish were measured, separated and identified. Relative abundance, constancy of occurrence and spatial distribution of catfish in sampling sites were determined. Temperature and salinity presented significant variations between sites and months. 6098 specimens were collected during the study years. Catfish were most abundant in the innermost sites of the bay, being considered frequent in sampling sites. Species presented significant variation between the sites. Genidens genidens was the most frequent and abundant species in Baía da Ribeira. Significant correlation of the abundance of catfish and temperature and salinity were not observed. Catfish were considered frequent in the sampling sites, possibly disclosing the importance of Baía da Ribeira for these species.