Gastropods - Feeding and Digestion in Molluscs

In several gastropods the digestion is extracellular. Though, some herbivore gastropods like Crepidula are ciliary feeders and have a digestive system identical to that of lamellibranchs. In them amylase is the just only extracellular enzyme; the digestive diverticula do not secrete any enzyme but are only absorptive in function. Crepidula has as well a crystalline style similar to those of lamellibranchs. Some herbivorous gastropods relating to Taenioglossa, Rapido Glossa and Pteropoda as well possess crystalline style. It is confined to those herbivorous gastropods that are microphagous feeders, involving rasping feeders that use radula. Patella, Haliotis, Aplysia and Helix are some another herbivorous gastropods that do not possess a crystalline style. Essentially in those forms in which extracellular digestion has replaced intracellular digestion, a crystalline style is not present.