Freshwater Ancient Fish Species Profiles
Bowfin (Amia calva) are bony fishes native to North America, who are related to gars in the infraclass Holostei. They are regarded as taxonomic relicts, being the sole surviving species of the order Amiiformes which dates from the Jurassic to the Eocene, persisting to the present. Their range is limited to much of the eastern United States and adjacent southern Canada, including the drainage basins of the Mississippi River, Great Lakes and various rivers exiting in the Eastern Seaboard or Gulf of Mexico. Their preferred habitat includes vegetated sloughs, lowland rivers and lakes, swamps and backwater areas; they are also occasionally found in brackish water.
Gars are an ancient holosteian order of ray-finned fish; fossils from this order are known from the Late Jurassic onwards. The family Lepisosteidae includes seven living species of fish in two genera that inhabit fresh, brackish, and occasionally marine, waters of eastern North America, Central America and the Caribbean islands. Their vascularised swim bladders can function as lungs, thus most gars surface periodically to take a gulp of air.
Knifefishes are an ancient fish species that comprise, at most, about 50 species of Central and South American fishes found in quiet lakes and lagoons. They are placed in three families: Gymnotidae (often called gymnotid “eels”); Apteronotidae; and Rhamphichthyidae. Some authorities, however, group all, together with the related electric eel, in a single family, Gymnotidae, while others recognize more than three families.
Lungfish, also known as salamanderfish, are freshwater fish that can be found in Australia, South America and Africa. There are six different species divided into two families, Lepidosirenidae, South American lungfish and African lungfish, and Ceratodidae, Australian lungfish. Lungfish can be traced to the Lower Devonian period and have changed little in the last million years. They are carnivorous predators that relish live foods and will eat fish, crayfish, crabs and practically anything else they find.