Body color of the Bowfin is dark olive above with lighter sides and cream-colored belly. The long dorsal fin is dark green with a narrow longitudinal olive-colored band near the top margin and another near the base. The males have a dark spot on the caudal fin, bordered with yellow or orange. Lower fins are green, vivid as fresh paint, during the breeding season. There are 66 to 68 scales in the lateral line. The dorsal fin contains 47 to 51 soft rays and the anal fin 9 or 10 rays. The head is more or less flattened on top and the mouth is large. The teeth are sharp and strongly set in the jaws. Weights of 6 to 8 pounds or more are commonly attained.
With the exception of rare specimens collected in Spirit and Okoboji lakes, the Bowfin is found primarily in sloughs and ponds of the Mississippi River. It has been observed in collections in the lower reaches of the Iowa-Cedar Rivers drainage and is probably present today in the lower reaches of all the major Mississippi River tributaries. This fish is extremely rare in the interior waters of the state.
Crayfish, fish, frogs, large insects &amp;amp; leeches.
11 lbs 9 oz; 31.5 in.- Pool 10, Mississippi River, Clayton County, January 1994 - Bill Greten, Blue Grass, Iowa
The Bowfin, sometimes called a dogfish, is a voracious eater and can survive almost any environment - including being out of the water for days - since it can also breath air. The Bowfin rivals the bullhead as Iowa's fish most able to handle any tough conditions.
The bowfin is a primitive type fish and the sole representative of an ancient fish family. Although the body feels smooth and leathery, it is actually covered with cycloid scales, which are smooth and have no ctenii or rough prickles like some of the other fishes.
Fossil remains of the ancestors of this fish are found in the rocks of Europe and the United States. The present day form is a voracious, hardy individual with a determination to live under any circumstances it may encounter. It prefers large quiet waters and is abundant in the boundary rivers and overflow backwaters. As in the gars, the swim bladder serves as a lung, giving the bowfin air breathing capability.
The ability to breathe air is attained early in life and is used most frequently at night and when water temperature is high, coinciding with periods of greatest activity. The bowfin is able to survive prolonged air breathing periods. Young bowfin have been observed surviving for 21 days in a pond with no standing water.
The bowfin is found primarily in sloughs and ponds throughout the Mississippi River. It also occurs in the southeast corner of Iowa in streams of the Lower Iowa and Lower Cedar River drainages. The bowfin is rare in the interior streams and natural lakes of Iowa but probably occurs in the lower reaches of all the Mississippi River’s major tributaries.
The bowfin occurs in variety of aquatic habitats including: swamps, marshes, sloughs, oxbows, bayous, backwaters, borrow pits, ditches, streams and glacial lakes. In many of its habitats including ditches and glacial lakes, this species is most abundant in sections having thick beds of aquatic vegetation or other cover. Along the Mississippi and other large rivers, Bowfin are more often found in backwaters and oxbows choked with aquatic vegetation, than in the main channel. Bowfin prefer quiet, clear water, tending to avoid areas with strong current and high turbidity yet are tolerant to silt, mud and high temperatures.
The bowfin spawns in the spring, usually in May, in shallow quiet bays or backwaters of a river. It is a nest-builder and deposits the eggs in a saucer-like depression on the bottom or over sticks and vegetation. The eggs are guarded and tended by the male until they hatch, and the young are herded about in schools until they are able to shift for themselves. Bowfin attain a length of 6 to 8 inches at the end of the first growing season and often reach 2 feet or more at maturity.
The Bowfin is primarily carnivorous, feeding largely on fishes of all kinds, frogs, crayfish, large insects and their larvae, leeches and other aquatic life.
The Bowfin in not commonly targeted by Iowa anglers, but as a predator it is caught regularly in areas where it lives. It is viewed as vulnerable according to the Iowa Wildlife Action Plan, but it not on the threatened or endangered species lists in Iowa (571 IAC 77.2(2) (2015)).
Recent stream sampling information is available from Iowa DNR's biological monitoring and assessment program.
Harlan, J.R., E.B. Speaker, and J. Mayhew. 1987. Iowa fish and fishing. Iowa Conservation Commission, Des Moines, Iowa. 323pp.
Loan-Wilsey, A. K., C. L. Pierce, K. L. Kane, P. D. Brown and R. L. McNeely. 2005. The Iowa Aquatic Gap Analysis Project Final Report. Iowa Cooperative Fish and Wildlife Research Unit, Iowa State University, Ames.
Illustration by Maynard Reece, from Iowa Fish and Fishing.