Biometric differences in Ucides cordatus (LINNAEUS, 1763) (Crustacea; Brachyura; Ocypodidae) as an indicative of environmental stress

Abstract

Growing urban development, port expansion, and the deployment of industries along the northeast coast of Brazil are some of the major threats to crustacean fauna that depend directly on the mangrove ecosystem to survive. In response to these environmental changes, the swamp ghost crab (Ucides cordatus) presents biological dysfunctions in body size to invest in mechanisms that regulate homeostasis. The present study aimed to evaluate the size and condition factor of crabs from two distinct mangrove areas, being an impacted area and a reference area. Male crabs were collected through the braking technique, weighed with an analytical balance and the width and length of the carapace were measured with a digital caliper. We used a t test to observe differences between two areas and different periods, and the power function (y = axb) for the ratio between the weight and width of the carapace of each individual was used in order to observe the type of growth. There were significant differences between the weight and length of the individuals between the two sample areas and the growth classified as negative allometric.