The Biology ofAporrhais pes-pelecani(L.) and A.serresiana(Mich.).

Abstract

1.Aporrhais pes-pelecanioccurs on muddy gravel at moderate depths and is specialized for burrowing in this.2. The mode of burrowing is described and also the formation of mucuslined inhalent and exhalent openings by the proboscis.3. There is a powerful respiratory current through the mantle cavity which also possesses three sets of ciliary currents for disposing of sediment carried in with this.4. The animal is a specialized detritus feeder selecting only material of plant origin. The radula consists of one central and three lateral teeth on each side, an indication that it is used for seizing as opposed to scraping,notthat the animal is carnivorous.5. The stomach possesses a well-developed ciliary sorting mechanism. The large crystalline style and gastric shield indicate that the animal is herbivorous, but there is no cellulase.