Balanus balanoides vs barnacle

Balanus balanoides and barnacle both are nouns.

Word	Noun	Adjective	Verb	Adverb
Balanus balanoides	Yes	No	No	No
barnacle	Yes	No	No	No

As nouns, barnacle is a hypernym of Balanus balanoides; that is, barnacle is a word with a broader meaning than Balanus balanoides:

Balanus balanoides: barnacle that attaches to rocks especially in intertidal zones
barnacle: marine crustaceans with feathery food-catching appendages; free-swimming as larvae; as adults form a hard shell and live attached to submerged surfaces

Other hypernyms of Balanus balanoides include cirriped, cirripede.

Balanus balanoides (noun)	barnacle (noun)
barnacle that attaches to rocks especially in intertidal zones	marine crustaceans with feathery food-catching appendages; free-swimming as larvae; as adults form a hard shell and live attached to submerged surfaces
	European goose smaller than the brant; breeds in the far north