gudgeon vs cyprinid fish

gudgeon and cyprinid fish both are nouns.

Word	Noun	Adjective	Verb	Adverb
gudgeon	Yes	No	No	No
cyprinid fish	Yes	No	No	No

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

gudgeon: small slender European freshwater fish often used as bait by anglers
cyprinid fish: soft-finned mainly freshwater fishes typically having toothless jaws and cycloid scales

Other hypernyms of gudgeon include cyprinid.

gudgeon (noun)	cyprinid fish (noun)
small slender European freshwater fish often used as bait by anglers	soft-finned mainly freshwater fishes typically having toothless jaws and cycloid scales
small spiny-finned fish of coastal or brackish waters having a large head and elongated tapering body having the ventral fins modified as a sucker