Length–weight Relationships of Bivalve Species Donax cuneatus and Meretrix casta along Gulf of Mannar, Southeast Coast of India

This study aims to describe the relationship between length and weight of the bivalves Donax cuneatus (Linnaeus, 1758) and Meretrix casta (Gmelin, 1791) along the Gulf of Mannar. A total of 1,791 individuals of two species were collected from October 2019 to December 2020. The length–weight relationship of both species has been estimated using the equation W = aL b . A common length–weight relationships, W = 0.0002 L 2.8882 for D. cuneatus , and W = 0.1971 L 2.3556 for M. casta were recorded. The results showed negative allometric growth in both the bivalve species. The coefficient of determination (r 2 ) was 0.9426 for Donax cuneatus and 0.9628 for Meretrix casta . Condition factor was estimated to be less than one throughout the study period for D. cuneatus and for M. casta it ranged from 0.81 to 1.38. This study provides a mathematical equation of the relationship between length and weight, and the condition of both the species along the Gulf of Mannar, southeast coast of India.