Estimating Diet of the Largemouth Bass in Ponds on the Sakaigawa Retarding Basin, as Carbon and Nitrogen Stable Isotope Analysis

Abstract

This study aimed to estimate the diet of largemouth bass (Micropterus salmoides), which is an alien species in Japan. Largemouth bass samples were collected from two ponds in the Sakaigawa Retarding Basin. Stable isotope ratios of carbon and nitrogen (δ¹³C and δ¹⁵N) were determined for the fishes. There was no difference in body length of juvenile largemouth bass between the two ponds. The estimated diet of largemouth bass in relatively large pond were organisms at the higher trophic level, regardless of their age. The estimated diet of largemouth bass in relatively small pond changed from planktons to organisms at the higher trophic level as their age growing.