Reproductive potential of uçá-crab, Ucides cordatus (Linnaeus, 1763) (Brachyura: Ucididae), in mangroves with different levels of conservation, in the São Paulo State, Brazil

Abstract

Mangroves act as nurseries for many animal species, to take refuge, find food and suitable place to reproduction and growth processes. It is one of the coastal ecosystems more impacted by humans, and can promote depletion or optimization of reproductive potential in some species. The present study aims to evaluate the fecundity of the uçá-crab in mangroves with distinct conservation level, being a pristine (Jureía-Itatins Ecological Station, Peruíbe Municipality) and other historically contaminated (Cubatão Mnicipality). Will be collected 70 ovigerous females by mangrove, in a same reproductive period (November to March). The females will be submitted to biometry (CW, cephalothoracic width; WW, wet weight; and WWE, wet weight of eggs). The total number of eggs by female will be quantified by gravimetric method, with dehydration, cleaning, weight of the dry eggs (WDE) and quantification of three sub-samples (0,5mg) per female. The total number of eggs (EN) will be obtained by a simple three rule, with the points of the relationship ENxCW fitted to function y=axb. The fecundity equations will be log-transformed and confronted by the t-test (parallelism/coincidence of straights), with the data submitted to a procedure for exclusion of size effect, and further evaluation of a depletion or potentialization of the reproduction of this species.