marine creature vs brute

marine creature and brute both are nouns.

Word	Noun	Adjective	Verb	Adverb
marine creature	Yes	No	No	No
brute	Yes	Yes	No	No

As nouns, brute is a hypernym of marine creature; that is, brute is a word with a broader meaning than marine creature:

marine creature: any of numerous animals inhabiting the sea including e.g. fishes and molluscs and many mammals
brute: a living organism characterized by voluntary movement

Other hypernyms of marine creature include animal, animate being, beast, creature, fauna.

marine creature (noun)	brute (noun)
any of numerous animals inhabiting the sea including e.g. fishes and molluscs and many mammals	a living organism characterized by voluntary movement
	a cruelly rapacious person

marine creature (adjective)	brute (adjective)
	resembling a beast; showing lack of human sensibility