Filial Cannibalism in the Paternal Mouthbrooding Cardinalfish Apogon lineatus: Egg Production by the Female as the Nutrition Source for the Mouthbrooding Male

We investigated about filial cannibalism by Apogon lineatus based on 25 mouthbrooding males sampled in Tokyo Bay, Japan. Eggs were found in the stomachs of all mouthbrooding males, indicating that Apogon lineatus performs partial brood cannibalism. The number of eggs in the stomachs ranged from 1015 to 9384, corresponding to 30% on average of the entire brood. This study revealed that mouthbrooding males could gain considerable energy by partial brood cannibalism during brood periods, that is, females would produce surplus eggs as the nutrition sources for starving males.