Diet and Feeding Behavior of Two Dragonets <i>Calliurichthys japonicus</i> and <i>Repomucenus huguenini</i> in Tosa Bay, Southern Japan

Diet and food selectivity of Calliurichthys japonicus and Repomucenus huguenini were investigat ed from March 1992 to February 1993 in Tosa Bay, Kochi Prefecture. The diet of C. japonicus was com posed of polychaetes, amphipods, gastropods, ophiuroids, bivalves, cumaceans, and other small ben thic animals. Amphipods were abundant in number both in spring and winter months, while poly chaetes and ophiuroids were the most dominant in autumn and summer, respectively. Calliurichthys japonicus actively selected gastropods and showed a more randomized feeding character than R. huguenini. In R. huguenini, polychaetes and amphipods were the most dominant prey items throughout the year. Polychaetes were most abundant in number from spring to autumn, while the amphipods dominated in winter. Although R. huguenini had a similar diet to that of C. japonicus, R. huguenini had a more selective and specialized diet than the C. japonicus, and actively selected decapods, isopods , ostracods, and cumaceans. The difference in feeding habits between the two species may be attributed to their difference in adult body-size and their ability to visually differentiate prey at their different death distributions.