a primitive North American freshwater bony fish, Amia calva, with an elongated body and a very long dorsal fin: family Amiidae
bowfin in American English
(ˈboʊˌfɪn)
US
noun
a primitive freshwater fish (Amia calva) of E North America, with a rounded tail fin and a long, narrow fin on its back: it is the only living member of an order (Amiiformes) of bony fishes