Food choice by the introduced crayfish Procambarus clarkii

摘要

Predicting the effects of invasive species demands detailed studies on intra and interspecific trophic interactions. To better understand the trophic role of Procambarus clarkii in rice fields, I quantified stomach contents and assessed temporal, ontogenetic and sexual trophic selection of macroinvertebrates. Detritus and plants occurred frequently in the stomach of P. clarkii, but animals formed the highest fraction of the diet. A seasonal pattern in the proportion of animals in the diet was observed for the total population, different sizes and both sexes. Pre-adults and adults tended to be more herbivorous, whereas juveniles tended to be predatory. Trophic selection of macroinvertebrates appeared related to their availability. Food choice by different life stages indicates that alterations in the demography or abundance of P clarkii may change its structural and functional trophic role in rice field aquatic ecosystems. [References: 61]