fish genus - any of various genus of fish

Cyprinodontidae, family Cyprinodontidae - large family of small soft-finned fishes; killifishes; flagfishes; swordtails; guppies

Fundulus heteroclitus, mummichog - silver-and-black killifish of saltwater marshes along the Atlantic coast of the United States

Fundulus majalis, may fish, mayfish, striped killifish - black-barred fish of bays and coastal marshes of the Atlantic and Gulf coasts of the United States