Hexanchus griseus vs six-gilled shark

Hexanchus griseus and six-gilled shark both are nouns.

Word	Noun	Adjective	Verb	Adverb
Hexanchus griseus	Yes	No	No	No
six-gilled shark	Yes	No	No	No

As nouns, Hexanchus griseus and six-gilled shark are synonyms defined as:

Hexanchus griseus and six-gilled shark: large primitive shark widely distributed in warm seas

Other synonyms of Hexanchus griseus include cow shark.

Hexanchus griseus (noun)	six-gilled shark (noun)
large primitive shark widely distributed in warm seas	large primitive shark widely distributed in warm seas