Effects of depth on diet of Chlamys hastata and Chlamys rubida

Abstract

Scallops are semi-mobile filter feeding bivalves; an important member of their ecosystems due to their ecological contributions and importance as bioindicators. Despite their importance, little is known about their diet and feeding habits. It is accepted that suspension feeding bivalves have the ability to select particles by size (Riisgård 1988), and perhaps by chemical/nutritional properties (Ward et al. 1998). In this study we aimed to answer the question as to whether scallop individuals, Chlamys rubida and Chlamys hastata, consumed different diets across depths and species, displayed through gut contents. This was done by capturing C. rubida and C. hastata individuals from two different depths and analyzing their diets via a random survey of the gut contents. An overall ANOSIM test of gut content assemblage showed no significant difference between species or depths (p-value= 0.35). This confirmed our null hypothesis that there would be no significant difference between diets of scallop individuals across species or depth. The same-diet phenomenon could be due to multiple reasons, including but not limited to the abundance of food at each depth or to the scallops’ ability to select food.