Diet Composition and Feeding Habits of Two Engraulid Fish Larvae (Engraulis Japonicus and Coilia Nasus) in the Nakdong River Estuary, Korea

Abstract

Choi, H.C.; Youn, S.H.; Huh, S.-H., and Park, J.M., 2018. Diet composition and feeding habits of two engraulid fish larvae (Engraulis japonicus and Coilia nasus) in the Nakdong River estuary, Korea. In: Shim, J.-S.; Chun, I., and Lim, H.S. (eds.), Proceedings from the International Coastal Symposium (ICS) 2018 (Busan, Republic of Korea). Journal of Coastal Research, Special Issue No. 85, pp. 346–350. Coconut Creek (Florida), ISSN 0749-0208.Engraulis japonicus and Coilia nasus are members of the family Engraulidae, and their larvae are important components in the estuarian ecosystems that they inhabit. The dietary study of fish larvae is essential to understanding early survival and recruitment in fish populations. This study investigated the dietary compositions and size-related dietary changes in E. japonicus and C. nasus larvae in the Nakdong River estuary. Larvae samples were collected monthly between April and August 2011 using an RN80 net at two stations in the estuary. Gut content analyses revealed that E. japonicus fed mostly on copepods, and secondarily on tintinnids and cladocerans, while C. nasus preferred to consume freshwater cladocerans. These dietary differences between the two larvae were closely related with habitat preference, which provided different local prey sources at each station. As the larvae of both species grew, the consumption of copepods for E. japonicus, and cladocerans for C. nasus, gradually increased, indicating distinct ontogenetic dietary changes. This dietary study of larval E. japonicus and C. nasus is important information for the development of fisheries, and can be implemented in related further studies of areas other than estuaries.