striped mullet vs gray mullet

striped mullet and gray mullet both are nouns.

Word	Noun	Adjective	Verb	Adverb
striped mullet	Yes	No	No	No
gray mullet	Yes	No	No	No

As nouns, gray mullet is a hypernym of striped mullet; that is, gray mullet is a word with a broader meaning than striped mullet:

striped mullet: most important commercial mullet in eastern United States
gray mullet: freshwater or coastal food fishes a spindle-shaped body; found worldwide

Other hypernyms of striped mullet include grey mullet, mullet.

striped mullet (noun)	gray mullet (noun)
most important commercial mullet in eastern United States	freshwater or coastal food fishes a spindle-shaped body; found worldwide
	highly valued lean flesh of marine or freshwater mullet