Fishes of Iowa
The state of Iowa is a diverse region, providing unique angling opportunities across the state. From the border rivers of the Mississippi to the Missouri, through farmponds, natural and man-made lakes, and interior rivers and streams, a rich fish population provides nearly every angler with the chance for an enjoyable outing.
Currently, 148 fish species can be found in Iowa waters. Each fish species is listed at the bottom of this page, and information is provided regarding fish characteristics, methods of identification, distribution and food habits, state record fish, tips to bring in the big one, and a brief biology of the fish.
Catfish and Bullheads
Ten species of catfish inhabit Iowa waters, including Iowa's most popular gamefish - channel catfish. Family members can be simply separated into three major groups: the large catfishes that include flathead catfish, blue catfish, and channel catfish, all of which often reach weights of more than 20 pounds; the bullheads, including black, yellow, and brown, which rarely exceed 4 pounds in weight; and the madtoms, represented by the tadpole madtom, slender madtom, stone cat, and freckled madtom, which are the smallest of the catfishes. Catfishes are easily distinguished from other fishes by their smooth scaleless bodies, eight elongated fleshy barbels or "whiskers" abouth their mouth, and the strong, sharp spines that are located at the insertion of the dorsal and pectoral fins.
Sunfish - Bass and Panfish
This family includes some of the most popular sportfishing species, such as the basses, bluegill, and crappies. Twelve species of sunfish inhabit Iowa waters, including three black bass species, six sunfish species, and three crappie-like members. Smallmouth bass are most abundant in streams, largemouth bass prefer quiet waters of lakes and large rivers, black and white crappie are found in both moderate to large-sized lakes and streams, green sunfish and orange-spotted sunfish are found nearly everywhere, and bluegills prefer lakes, ponds and the backwaters of large rivers. All are characterized by having at least one spine at the front part of the dorsal fin, which is continuous with the rear portion. Their body is deeply compressed laterally, and the attachment of the pelvic fins is far forward, nearly beneath the pectoral fins. There are three or more spines at the front of the anal fin, and the scales are ctenoid, which means they have rough edges.
The the popular gamefish walleye, sauger and yellow perch are some of the 20 representatives of the perch family in the state, with the remaining members all being various species of darters. Members of the perch family are characterized by rather slender, elongated bodies and by a large bone on the gill cover which ends in a flat spine. The dorsal fins are a very distinctive characteristic of the family with a definite separation evident between the anterior spiny portion and the soft portion to the posterior.
The native brook trout and the naturalized rainbow and brown trout are the only coldwater gamefish in Iowa. All Iowa trout streams, numbering more than 100, are located in nine northeastern counties, roughly east of the Cedar River and north of the cities of Cedar Rapids and Maquoketa. Most coldwater streams are in private ownership, and trout fishing is allowed by public access agreements between the Department of Natural Resources and the landowners. Natural reproduction of brown and brook trout presently occurs in a few streams, but for the most part trout inhabiting Iowa streams are produced at one of the three trout hatcheries located at Manchester, Decorah and Big Spring.
Respected by anglers, these important gamefish have three different species in the state: northern pike, muskellunge, and grass pickerel. Pike are voracious fish and primary predators that are held in high esteem by the angling fraternity. As a result, considerable effort has been put forth for hatchery production of these fish in order to replenish depleted populations. Members of the pike family have similar physical characteristics that easily identify them. The body is round-shaped and elongated with a frontal-flattened head, along with a duck-bill shaped jaw lined with large, canine-like teeth. The dorsal fin is inserted far back on the body.
The Iowa DNR has used data collected from muskellunge in the Iowa Great Lakes (East and West Okoboji, and Spirit Lake) to create a length-weight conversion chart to assist catch-and-release anglers in determining the weight of their fish. This chart is available as both a PDF and an Excel file.
Once referred to as "sea basses", three members of this family are found in Iowa. Two native species are the white bass and yellow bass, and the hybrid striped bass is an exotic speices. This hybrid, also known as the Palmetto bass, is the cross of a female ocean striped bass (Morone saxatilis) and a male white bass. This fish, which does not occur in natural populations, was originally hybridized in southern United States as a rapid growing fish adaptable to freshwater environments. Hybrid striped bass also provide a trophy fishery, with the current state record weighing nearly 20 pounds. Hybrid striped bass have been stocked recently in urban lakes such as Lake Manawa, Gray's Lake, Blue Heron Lake and Ada Hayden Lake, to improve the quality of these urban fisheries.
Suckers, as their name implies, are mainly bottom feeders, foraging by sucking up materials from the bottom. Some members of the family, mainly the buffalofishes (bigmouth and smallmouth buffalo), filter plankton for food directly from the water. Suckers are able to consume aquatic insects and their larvae, small mollusks, algae, detritus and tiny crustaceans. They find food items by touch, taste and sight, and survive well in turbid waters. This ability to adapt to diverse environments contributes to, at times, extraordinarily dense populations. Sucker family members can surpass the total biomass of all other fishes in most Iowa rivers and impoundments, as well as in some natural lakes. Despite these high populations, suckers are seldom taken by Iowa anglers, except in very early spring. Spring spawning runs of the redhorses and white sucker are notable exceptions, when many are taken by bait fishing and snagging.
The mouth of all suckers is located on the underside of the head and is tipped with fleshy protrusile lips. All family members are soft-rayed fishes with toothless jaws, scaleless heads, cycloid scales (smooth-edged), forked caudal fin, and a single, continuous, fleshy dorsal fin. Many suckers look like and are often confused with minnow species, but they differ in many features. Most of the suckers have 10 or more dorsal fin rays, which is always one or two more than the native minnows. The pharyngeal tooth pattern is wholly different in the suckers.
This family includes many common bait species of fish found in the state, as well as the common carp. The Cyprinidae family is the most diverse and dynamic group of fishes in Iowa and perhaps the world. Members of this family can be found in all Iowa rivers and streams and in most lakes. Their range of environmental tolerance varies from those that are on the very extremes of their natural continental distribution and are threatened with extirpation, to those with expanding distribution and abundance. Minnows form the basis of our natural stream fish fauna, and they have filled most of the habitat niches through evolution and natural selection.
Most small fishes, regardless of species, are erroneously called "minnows", which leads to misidentification. Cyprinids are small in size, rarely reaching more than 12 inches in length - even as adults. Not all members of the minnow family are small, however; introduced and exotic fishes such as common carp,
goldfish, bighead carp, silver carp and white amur (grass carp) attain sizes that rank with the largest freshwater fishes.
Cyprinids share several common taxonomic characters, separating them from other fish families. External features include: scaleless head, toothless jaws, lack of adipose fin, lack of appendages at the base of the pelvic fins, and a single, soft dorsal fin in native species with less than 10 rays.
Primitive fishes in Iowa include the paddlefish, bowfin, sturgeon, gar and lamprey. They are described as "primitive" because they lack one or several of the features characterizing more "advanced" fish species, such as jaws, ganoid scale type, lack of vertebrae, body structure, or phylogenetic relations.
Iowa has several peculiar families with only one or two members. Some of the more common fish include the freshwater drum, brook stickleback, and gizzard shad. Mottled and slimy sculpins are found in the trout streams of northeast Iowa. American eel, mooneye, and burbot are only found in the largest of Iowa's rivers. Other unique Iowa fish include the central mudminnow, brook silverside, banded killifish, blackstripe topminnow and the trout-perch.
*Note: This information is from Iowa Fish and Fishing (Mayhew, J. (editor). 1987. Iowa Department of Natural Resources, Des Moines, Iowa. 323 pp.)