topminnow vs Xyphophorus

topminnow and Xyphophorus both are nouns.

Word	Noun	Adjective	Verb	Adverb
topminnow	Yes	No	No	No
Xyphophorus	Yes	No	No	No

topminnow (noun)	Xyphophorus (noun)
small usually brightly-colored viviparous surface-feeding fishes of fresh or brackish warm waters; often used in mosquito control	swordtails
freshwater fish of Central America having a long swordlike tail; popular aquarium fish