pike-perch vs walleye

pike-perch and walleye both are nouns.

Word	Noun	Adjective	Verb	Adverb
pike-perch	Yes	No	No	No
walleye	Yes	No	No	No

As nouns, walleye is a hyponym of pike-perch; that is, walleye is a word with a more specific, narrower meaning than pike-perch:

Other hyponyms of pike-perch include dory, jack salmon, Stizostedion vitreum, walleyed pike.

pike-perch (noun)	walleye (noun)
any of several pike-like fishes of the perch family	pike-like freshwater perches
	strabismus in which one or both eyes are directed outward