Morfologia externa das tocas de duas espécies de caranguejos estuarinos

Abstract

Crab burrows provide important insights into the ecology, physiology, and behavior of your resident. In this study the external morphology of Ucides cordatus and Uca maracoani burrows of an estuary were characterized and compared to determine their relationship with the characteristics of their resident and variation over time. It was observed the opening diameter (DO) and the total depth (TD) of the burrow, presence of the individual (PI), presence of material near the edge (PNE), shape of the opening (SO), slope of the opening (perpendicular or inclined to the ground) (SO), presence of ornaments (PO) and presence of tracks (PT). Measurements of the burrows of both species indicate excavation habits, frequency of locomotion and habitats with similar sediments. The DO of the burrows of U. cordatus is significantly larger than those of U. maracoani , representing the difference in size between the species and indicating that the opening diameter of the burrows can serve as an indirect parameter to evaluate the size of the population. Because there was a continuous increase in the percentage of inclined burrows in the first six months of sampling in the U. maracoani burrows, it is possible that the average age of the population increased, since individuals tend to have steeper slopes when they get older. In U. cordatus , the presence of fresh mud in the opening in its burrows is recurrent, being this substrate one of the factors used to verify if the burrow is being occupied. The species also presented ornaments that indicate a territorialist behavior. We conclude that the morphology of the burrows of the two species is related to the characteristics of its inhabitants and that the construction of the burrows is related to the environment.