bivalve vs scollop

bivalve and scollop both are nouns.

Word	Noun	Adjective	Verb	Adverb
bivalve	Yes	Yes	No	No
scollop	Yes	No	Yes	No

As nouns, scollop is a hyponym of bivalve; that is, scollop is a word with a more specific, narrower meaning than bivalve:

bivalve: marine or freshwater mollusks having a soft body with platelike gills enclosed within two shells hinged together
scollop: edible marine bivalve having a fluted fan-shaped shell that swim by expelling water from the shell in a series of snapping motions

Other hyponyms of bivalve include clam, cockle, oyster, ark shell, blood clam, mussel, escallop, scallop, piddock.

bivalve (noun)	scollop (noun)
marine or freshwater mollusks having a soft body with platelike gills enclosed within two shells hinged together	edible marine bivalve having a fluted fan-shaped shell that swim by expelling water from the shell in a series of snapping motions
	edible muscle of mollusks having fan-shaped shells; served broiled or poached or in salads or cream sauces
	thin slice of meat (especially veal) usually fried or broiled

bivalve (adjective)	scollop (adjective)
used of mollusks having two shells (as clams etc.)