Feeding Habits of the Cardinalfish Apogon lineatus in Tokyo Bay, Japan

抄録

The feeding habits of Apogon lineatus in Tokyo Bay were examined based on 677 specimens. The vacuity index was relatively high (26.1%). The diet of the fish was composed primarily of shrimps (frequency of occurrence (%F), 76.2; weight percentage (%W), 73.9; ranking index (RI), 5631), especially Crangon affinis (%F, 59.2; %W, 56.2; RI, 3327). Fishes (%F, 5.9; %W, 4.2; RI, 25), including Chaeturichthys sciistius, were also found in the diet. Shrimps were found to be important throughout the year. However, conspeciflc egg masses with the surfaces digested were observed in the stomachs of many males during the breeding season. This finding suggests that this species engages in filial cannibalism.