On the Mechanism of Ventilation inAphrodite Aculeata

Abstract

In Aphrodite aculeata the floor of the respiratory cavity is formed by the dorsal body wall, the roof is formed by the elytra. Ventilation is effected by pumping movements both of the dorsum and of the elytra. During inspiration water is sucked into the respiratory cavity via lateral inspiratory openings in the felt. During expiration the inspiratory openings are closed, and dorsum and elytra move towards each other. Consequently, the water in the respiratory cavity is forced out through the exhalent aperture, situated at the tip of the anal extermity. When burrowing, the animal holds its tail in an upturned position above the sand. It has free access to the water via the space formed, during expiration, between ventral body surface and sand.