| regnum = [[ఏనిమేలియా]]
| phylum = [[మొలస్కా]]
| classis = '''
| classis_authority = [[లిన్నేయస్]], []
| subdivision_ranks = [[ఉపతరగతులు]]
'''ఆల్చిప్పలు''' [[మొలస్కా]] జాతికి చెందిన జంతువులు.
'''Bivalves''' are [[mollusc]]s belonging to the class '''Bivalvia'''. They have two-part [[animal shell|shell]]s, and typically both valves are [[symmetry|symmetrical]] along the hinge line. The class has 30,000 [[species]], including [[scallop]]s, [[clam]]s, [[oyster]]s and [[mussel]]s. Other names for the class include '''Bivalva''', '''Pelecypoda''', and '''Lamellibranchia'''.
Bivalves are exclusively aquatic; they include both marine and freshwater forms. However some, for instance the mussels, can survive out of water for short periods by closing their valves.
Bivalves are unique among the molluscs for lacking a [[radula]]; they feed by siphoning and filtering large particles from water. Some bivalves are [[Fauna (animals)#Epifauna|epifaunal]]: that is, they attach themselves to surfaces in the water, by means of a [[byssus]] or organic cementation. Others are [[Fauna (animals)#Infauna|infaunal]]: they bury themselves in sand or other sediments; these forms typically have a strong digging foot. Some bivalves, such as [[scallop]]s, can swim.