Thalassoma bifasciatum vs bluehead

Thalassoma bifasciatum and bluehead both are nouns.

Word	Noun	Adjective	Verb	Adverb
Thalassoma bifasciatum	Yes	No	No	No
bluehead	Yes	No	No	No

As nouns, Thalassoma bifasciatum and bluehead are synonyms defined as:

Thalassoma bifasciatum and bluehead: small Atlantic wrasse the male of which has a brilliant blue head

Thalassoma bifasciatum (noun)	bluehead (noun)
small Atlantic wrasse the male of which has a brilliant blue head	small Atlantic wrasse the male of which has a brilliant blue head