family Mugilidae vs fish family

family Mugilidae and fish family both are nouns.

Word	Noun	Adjective	Verb	Adverb
family Mugilidae	Yes	No	No	No
fish family	Yes	No	No	No

As nouns, fish family is a hypernym of family Mugilidae; that is, fish family is a word with a broader meaning than family Mugilidae:

family Mugilidae (noun)	fish family (noun)
grey mullets	any of various families of fish