sea catfish vs siluriform fish

sea catfish and siluriform fish both are nouns.

Word	Noun	Adjective	Verb	Adverb
sea catfish	Yes	No	No	No
siluriform fish	Yes	No	No	No

As nouns, siluriform fish is a hypernym of sea catfish; that is, siluriform fish is a word with a broader meaning than sea catfish:

sea catfish: any of numerous marine fishes most of which are mouthbreeders; not used for food
siluriform fish: any of numerous mostly freshwater bottom-living fishes of Eurasia and North America with barbels like whiskers around the mouth

Other hypernyms of sea catfish include catfish.

sea catfish (noun)	siluriform fish (noun)
any of numerous marine fishes most of which are mouthbreeders; not used for food	any of numerous mostly freshwater bottom-living fishes of Eurasia and North America with barbels like whiskers around the mouth