Population biology of some species of crabs along Goa, west coast of India

Abstract

The population biology of brachyuran crab species namely Leptodius exaratus, Epixanthus frontalis, Metopograpsus frontalis and Heteropanope glabra, were examined at monthly interval from March, 2014 to August, 2015 along the five intertidal habitats of Goa. Out of 4068 crab samples, 46 percent were males and 54 percent females, of which 22 percent were ovigerous females. The maximum carapace width (21.6 mm) was observed in E. frontalis and minimum (9.0 mm) in H. glabra. Seasonally, the L. exaratus, M. frontalis and H. glabra were abundant during the pre-monsoon season whereas, E. frontalis was abundant in the post-monsoon season. The sex-ratio revealed that males and females were abundant during monsoon whereas gravid females were found in plenty during both pre-monsoon and post-monsoon seasons. In overall size - frequency distribution, the males exceeded the females in L. exaratus, M. fontalis and H. glabra. The Chi-square test revealed a significant ratio of male and female, only in L. exaratus and H. glabra. The fecundity index was highest in M. frontalis (3630) and least in H. glabra (648).