Comparisons of prey items in the stomach and intestines of three species of emperor fish (Pisces, Lethrinidae)

The contents of stomach and intestines of emperor fishes were compared to determine their usefulness in dietary analyses. Three species of emperor fishes, Lethrinus atkinsoni, L. nebulosus and L. obsoletus, captured using baited trap nets and by angling and spearing etc., and landed at a fish market in Ishigaki Island, Okinawa, Japan, were used. For all species, a significantly higher frequency of prey occurred in the intestines compared to the stomach when fish baits were excluded from the analysis. The contents of the intestines provide the best information on feeding habits of the emperor fishes, however, those prey animals lacking hard tissue structures may be underestimated.