HOW MOLLUSCS USE THEIR MUSCULAR FOOT

Molluscs have a strong muscular foot that they use for capturing their prey in the case of cephalopods, for crawling in the case of gastropods and for digging into the sand in the case of bivalves. In this video you can see how a bivalve uses its muscular foot to dig itself into the sand. You can see how it leaves its syphons  above the level of the sand as it uses them for filtering the water. Molluscs are filter feeders, they take in water through one syphon and the water comes out through the other. They never bury their syphons so as to be able to continue doing this.