Insights of the Population Structure and Breeding Biology of a Xanthid Crab <scp><i>Etisus laevimanus</i></scp> Randall, 1840, on the Rocky Intertidal Region of the Gujarat Coast

The population structure and breeding biology of a Xanthid crab, <i>Etisus laevimanus</i> Randall, 1840, a commonly occurring species on the rocky intertidal region of Saurashtra coast of Gujarat State, India, were investigated. Samples were collected from the intertidal region for 12 consecutive months during low tide using catch per unit effort in a 500 m² area. The individuals were categorized into male, non-ovigerous female, or ovigerous female. For fecundity estimation, the total number of eggs, size of eggs, and weight of egg mass were measured along with the carapace width and body weight of the respective ovigerous females. Sexual dimorphism was evident in the collected samples, with males being significantly larger than females. The overall as well as monthly sex ratio was female-biased. Size frequency distribution showed a bimodal frequency distribution in males while being unimodal in females. The occurrence of ovigerous females throughout the year suggests that the species has a continuous breeding pattern with peaks from December to April. The total number of eggs, size of eggs, and weight of the egg mass showed a significantly positive correlation with the carapace width of the ovigerous females.