mudcat vs freshwater fish

mudcat and freshwater fish both are nouns.

Word	Noun	Adjective	Verb	Adverb
mudcat	Yes	No	No	No
freshwater fish	Yes	No	No	No

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

mudcat: flesh of scaleless food fish of the southern United States; often farmed
freshwater fish: flesh of fish from fresh water used as food

mudcat (noun)	freshwater fish (noun)
large catfish of central United States having a flattened head and projecting jaw	flesh of fish from fresh water used as food
flesh of scaleless food fish of the southern United States; often farmed