The sixgill sawshark, Pliotrema warreni is a sawshark of the family Pristiophoridae. Presence of six pairs of gill slits highlights this genus among sharks; outside Hexanchiformes order, Pliotrema is the only shark genus with more than five gill slits. Unlike other sawsharks, the barbs on this shark's rostrum continue onto the sides of the head. Its barbels are also closer to its mouth than in other species. At maximum, females can reach over 136 cm long, and males can reach over 112 cm long.
Camelobaetidius is a genus of small minnow mayflies in the family Baetidae. There are at least 40 described species in Camelobaetidius.
Drunella coloradensis is a species of spiny crawler mayfly in the family Ephemerellidae. It is found in Central America and North America. In North America its range includes southwestern, northern Canada, northern Mexico, the western United States, and Alaska.
Epeorus dispar is a species of flatheaded mayfly in the family Heptageniidae. It is found in North America.
Ameletus lineatus is a species of combmouthed minnow mayfly in the family Ameletidae. It is found in North America.
Acentrella insignificans is a species of small minnow mayfly in the family Baetidae. It is found in Central America to North America. In North America its range includes southwestern, northern Canada, northern Mexico, the northern, southwestern United States, and Alaska.
Ephoron album, the white fly, is a species of pale burrower mayfly in the family Polymitarcyidae. It is found in North America.
Ameletus subnotatus is a species of combmouthed minnow mayfly in the family Ameletidae. It is found in all of Canada, the northern, and southwestern United States.
Callibaetis pictus is a species of small minnow mayfly in the family Baetidae. It is found in Central America and North America. In North America its range includes all of Mexico, the northern, and southwestern United States.
Drunella cornuta is a species of spiny crawler mayfly in the family Ephemerellidae. It is found in North America.
Ameletus ludens is a species of combmouthed minnow mayfly in the family Ameletidae. It is found in North America.
Callibaetis floridanus is a species of small minnow mayfly in the family Baetidae. It is found in Central America and North America. In North America its range includes all of Mexico, the southern, and northeastern United States.
Drunella tuberculata is a species of spiny crawler mayfly in the family Ephemerellidae. It is found in North America.
Ecdyonurus criddlei, the little slate-winged dun, is a species of flatheaded mayfly in the family Heptageniidae. It is found in Central America and North America. In North America its range includes southwestern Canada, northern Mexico, the western United States, and Hawaii.
Baetis bicaudatus is a species of small minnow mayfly in the family Baetidae. It is found in southwestern, northern Canada, the western United States, and Alaska.
Ephemerella aurivillii is a species of spiny crawler mayfly in the family Ephemerellidae. It is found in Europem, Northern Asia and North America. In North America its range includes all of Canada, the northern, southwestern United States, and Alaska.
Heptagenia solitaria is a species of flatheaded mayfly in the family Heptageniidae. It is found in southwestern and northern Canada, and the western United States.
Drunella flavilinea is a species of spiny crawler mayfly in the family Ephemerellidae. It is found in Central America and North America. In North America its range includes southwestern, northern Canada, northern Mexico, and the western United States.
Siphlonurus occidentalis is a species of primitive minnow mayfly in the family Siphlonuridae. It is found in Central America to North America. In North America its range includes southwestern, northern Canada, all of Mexico, the western United States, and Alaska.
Ameletus vernalis is a species of combmouthed minnow mayfly in the family Ameletidae. It is found in southwestern Canada and the western United States.
