Worldwide distribution of the sucker family is confined mainly to North America except for two or perhaps three species that are indigenous to Asia. In this continent there are 64 members in the sucker family, of which l6 species from 7 genera have been collected in Iowa. Several species of suckers are listed as threatened or have been extirpated from our waters. Two species of chubsuckers, the lake chubsucker (Erimyzon succetta) and creek chubsucker (E. oblongus), have not been collected for more than four decades and are considered absent. Several additional sucker species, including blue sucker, black buffalo, river redhorse, greater redhorse, and black redhorse are listed as rare or threatened. The latter three species may actually be extirpated since they have not been collected in recent years.

All fishes in the sucker family possess pharyngeal teeth in the throat, which are tooth-like structures used for crushing food. Many suckers are identified by the configuration of these teeth. Some species have thin, comb-like pharyngeal teeth for filtering plankton directly from the water like Carpiodes and Ictiobus. Others, such as Moxostoma, Catostomus, and Cyceleptus, have strong, flat-topped, molar-like structures that are used for crushing and grinding mollusks and crustaceans.

Suckers, as their name implies, are mainly bottom feeders, foraging by sucking up materials from the bottom, separating out the indigestible detritus and ejecting it through the mouth and operculum. At other times some members of the family, mainly the buffalofishes, filter plankton for food directly from the water. 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.

The suckers are well-adapted to bottom foraging. Being equipped with pharyngeal teeth and protrusile lips, they consume aquatic insects and their larvae, small mollusks, algae, detritus and minute crustaceans. They are able to find food items by both touch and taste, as well as by sight, and survive well in turbid waters. This ability to adapt to widely varying environments may be responsible for their potential to develop into extraordinarily dense populations. Sucker family members in most locations surpass the total biomass of all other fishes in most Iowa rivers and impoundments, as well as in some natural lakes.

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. These fisheries are, for the most part, important in only a few localities. Buffalofish are often speared for food when they spawn in the shallow, marsh-like habitat. Sucker flesh has a delicate, sweet flavor, but the numerous small Y-shaped meristic bones detract from the palatability unless they are scored before cooking in hot grease. Smaller members of the sucker family and the young of the larger species are the principal source of forage for predator fishes and as bait for sport fish.

Buffalofishes are very important to commercial fishing in Iowa. Over l l/2 million pounds are harvested each year from the Mississippi and Missouri rivers, river impoundments and natural lakes. Value of this catch is about $350,000. The fishery is comprised of about equal proportions of bigmouth and smallmouth buffalo, with black buffalo rarely netted. Buffalofish populations sometimes reach very high densities with as many as 600 pounds per acre removed from some natural lakes. Carpsuckers, redhorse and other species are also marketed for food-fish, but the demand for them is light.

The abundance and distribution of suckers has declined in Iowa over the last century, and the factors responsible for the decline are not completely understood. All indicators point strongly towards a general and widespread decrease in environmental habitat quality that favors other fishes, which is largely the result of intensified agricultural practices, industrial development and the modification of stream channels to promote rapid drainage. Unregulated commercial fishing for sucker family members has also taken its toll on population abundance, particularly along the Mississippi River.

*Mayhew, J. (editor). 1987. Iowa Fish and Fishing. Iowa Department of Natural Resources, Des Moines, Iowa. 323 pp.