Locomotion and motion of the mollusks

Bivalves
attachment--byssal threads
movement in the substrate
solifluction
elongation and contraction of the foot
siphons
keeping the shell closed-catch muscle fibers
retractor muscles
keeping the shell articulated, ligaments and teeth

Scaphopods or tooth or tusk shells
use foot and tentacles to search for food

Arthropods
Jointed appendage