pirana vs characid

pirana and characid both are nouns.

Word	Noun	Adjective	Verb	Adverb
pirana	Yes	No	No	No
characid	Yes	No	No	No

As nouns, characid is a hypernym of pirana; that is, characid is a word with a broader meaning than pirana:

pirana: small voraciously carnivorous freshwater fishes of South America that attack and destroy living animals
characid: any freshwater fish of the family Characinidae

Other hypernyms of pirana include characin, characin fish.

pirana (noun)	characid (noun)
small voraciously carnivorous freshwater fishes of South America that attack and destroy living animals	any freshwater fish of the family Characinidae