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

Abstract

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