Feeding habits of Saurida elongata in Haizhou Bay, Shandong, China, based on stomach contents and stable isotope.

Abstract

Saurida elongata, a warm-water offshore benthic fish, is one of the dominant species in Haizhou Bay and plays an important role in the food web. Based on samples collected from bottom trawl surveys in Haizhou Bay, we examined the feeding habits of Saurida elongata based on both stomach content and stable isotope analyses. The results showed that the main prey species of Saurida elongata were Metapenaeopsis dalei, Loligo spp., Cryptocentrus filifer, Engraulis japonicus, Chaeturichthys hexanema, Apogonichthys lineatus, Syngnathus acus and Callionymus beniteguri. The range of δ13C value was -19.39‰ to -16.23‰, with an average value of (-18.01±0.85)‰. There was no correlation between body length and δ13C values. The value of δ15N ranged from 9.56‰ to 13.36‰, with an average value of (11.77±0.86)‰, which was significantly positively correlated with body length. There was substantial difference in the contribution of food organism among diffe-rent body length groups. With the increases of body size, predation ability and morphology of feeding organs gradually improved, and the proportion of prey organisms changed, which might be the main reason for the ontogenetic variation in feeding habits. This study could contribute to understand the feeding ecology of snake mullet in Haizhou Bay and provide basic information for the nutritional dynamics of the Haizhou Bay food web.