SPATIO-TEMPORAL VARIATION OF THE ICHTHYOFAUNA IN THE ESTUARY FROM MANAMO CHANNEL, ORINOCO RIVER DELTA, VENEZUELA

Abstract

The delta of Orinoco River constitutes a long estuarine extension of a great importance to fisheries at Venezuela, because, it is an indispensable area for reproduction, feeding and growing of several fish species, most of them with a commercial application. The purpose of this research was to identify and analyze the changes in fish diversity and the structural dynamic of the community at four zones of channel Manamo, during dry and rainy season. Samples were taken on March and May for dry period and July and August for rainy season. A total of 48 species were identified, grouped into 24 families and 42 genera. The diversity was higher in Bajo del Medio during the dry season (2.58 bits/ind), decreasing to 1.66 bits/ind in el Pajar (rains). The PERMANOVAS analyzes showed statistical differences in the composition of species with respect to the climate season (psed-F = 0.0365, p <0.05), but not between the sampling stations (psed-F 0.6668; p < 0.05). The results indicated that the fish fauna of the region is composed of elements characteristic of an estuary, being the climate seasons the most important factors for the evaluated group and this reflects the seasonal nature of this community.