Mouth morphology of the diving beetle Hyphydrus japonicus (Dytiscidae: Hydroporinae) is specialized for predation on seed shrimps

Two-shelled organisms, such as bivalves and seed shrimps, protect themselves from external stresses by firmly closing both shells. We found that larvae of the diving beetle Hyphydrus japonicus Sharp, 1873 (Dytiscidae: Hydroporinae) frequently prey on seed shrimps. Other predatory aquatic insects have difficulty in capturing seed shrimps owing to the general form of the insects’ mandibles. Larvae of Hyphydrus japonicus bear a projection on the...