stickleback vs acanthopterygian

stickleback and acanthopterygian both are nouns.

Word	Noun	Adjective	Verb	Adverb
stickleback	Yes	No	No	No
acanthopterygian	Yes	No	No	No

As nouns, acanthopterygian is a hypernym of stickleback; that is, acanthopterygian is a word with a broader meaning than stickleback:

stickleback: small (2-4 inches) pugnacious mostly scaleless spiny-backed fishes of northern fresh and littoral waters having elaborate courtship; subjects of much research
acanthopterygian: a teleost fish with fins that are supported by sharp inflexible rays

Other hypernyms of stickleback include spiny-finned fish.

stickleback (noun)	acanthopterygian (noun)
small (2-4 inches) pugnacious mostly scaleless spiny-backed fishes of northern fresh and littoral waters having elaborate courtship; subjects of much research	a teleost fish with fins that are supported by sharp inflexible rays