Variations in food resource usage among eight fish species inhabiting inside and outside Jinju Bay, Korea

Abstract

Jinju Bay is a semi-closed bay located on the mid-southern coast of Korea. The dietary habitats of eight dominant fish species-Liparis tanakae (Tanaka's snailfish), Zoarces gillii (an eelpout), Pennahia argentata (silver croaker), Conger myriaster (whitespotted conger), Callionymus valenciennei (Valenciennes' dragonet), Thryssa kammalensis (Kammal thryssa), Sillago japonica (Japanese whiting), and Pholis fangi (a gunnel)-collected from inside and outside of Jinju Bay were analyzed using stomach content analyses. As a result of multivariate analysis for each season, there were significant differences in dietary composition between species and sampling sites in all seasons, except between study sites during summer The eight common species were divided into four groups based on the cluster analysis. The first group contained C. valenciennei and Z. gillii, which showed preferences for amphipods, while the second group, comprising T. kammalensis, fed mainly on crabs and mantis shrimps. The two species (P. fangi and S. japonica) in the third group tended to specialize in feeding on polychaetes, whereas the three species (L. tanakae, C. myriaster, and P. argentata) in the fourth group preyed on carid shrimp and teleosts. Although the eight species occurred in the same habitat and ingested a similar range of food resources, the contributions of different prey items were different in each species' diet-differences in food resource use between species were evident. In conclusion, the results of stomach content analyses of the eight species showed evidence of ecological separation between species occurring inside and outside Jinju Bay.