Ichthyoplankton variations in two mangrove creeks of the curuçá estuary, pará, Brazil

Abstract

Fish larvae diversity and abundance were compared between two mangrove creeks (C1 and C2) of the Curuçá Estuary, state of Pará, Brazil, from November 2003 to September 2004. Both habitats exhibited similar taxa composition, with 14 families and 32 identified species. The engraulids were the most abundant, representing 60% and 79% of the individuals in C1 and C2, respectively, while the carangids exhibited the highest diversity, with seven species. Monthly larval abundance in C1 followed the same variation pattern as salinity, with significantly more individuals at the beginning of the rainy season (November to January) and a minimum at the end of the rainy period (MAY). Larvae in C1 were predominant at night and during flood tides. Ichthyoplankton abundance was lower in C2 than C1, but remained constant over time, except for the month of July, when larvae were statistically more abundant. Larvae were more numerous in the daytime and during ebb tides. Differences in the nychthemeral and monthly abundances between the two creeks were related to the ontogenic stages of the larvae, with a predominance of pre-flexion/flexion stages in C1 and the post-flexion stage in C2.