bullhead vs siluriform fish

bullhead and siluriform fish both are nouns.

Word	Noun	Adjective	Verb	Adverb
bullhead	Yes	No	No	No
siluriform fish	Yes	No	No	No

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

bullhead: any of several common freshwater catfishes of the United States
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 bullhead include catfish.

bullhead (noun)	siluriform fish (noun)
freshwater sculpin with a large flattened bony-plated head with hornlike spines	any of numerous mostly freshwater bottom-living fishes of Eurasia and North America with barbels like whiskers around the mouth
any of several common freshwater catfishes of the United States