Pirate Perch

 

Characteristics

A stout, dark-colored fish, with a single dorsal fin and ctenoid scales on its head and body. Its tail fin is slightly notched. The anus is far forward of the anal fin and located on the throat of adults. Its mouth is large and oblique with the lower jaw projecting forward. Many very small villiform teeth in bands are on the upper and lower jaws. The gill cover has a sharp spine and the rear edge of the preopercle is strongly serrated. The dorsal fin has 2-3 short spines with 10-11 rays, anal fin 2-3 spines with 6-7 rays, and the pelvic fin has a single spine with 6 rays. The lateral line is incomplete or absent with 48-59 lateral series scales. Its upper body is dark olive to black with the sides lighter and the belly yellowish. The back and sides are thickly speckled with black, and there are two narrow, verticle bars at the base of the caudal fin. Adults are commonly 3- to 4.5-inches long, with a maximum length of 5-inches.

Distribution

 

Widely scattered locations along the Mississippi River and several major tributary streams. Most often found in the quiet pools and backwaters with clear, warm water, without current and abundant aquatic plants or organic debris for cover. Recent fish collections have failed to document this fish at many earlier surveyed sites, which shows their range and abundance have decreased.

Foods

Immature aquatic insects, small crustaceans and occasionally small fish.

State Record

State Records are not documented for non-game species

Expert Tip

None

Details

The Pirate Perch is listed as a species of special concern in Iowa. It only lives in scattered locations along the upper pools of the Mississippi River and in the lower Cedar River watershed. Recent collections have not found the Pirate Perch at many earlier survey sites, showing a decline in distribution and abundance.

The Pirate Perch is found in many lowland habitats from natural lakes, overflow ponds and low gradient streams to marshes, swamps, and roadside pools. It lives in areas with dense cover such as aquatic plants, debris, or undercut banks and bottoms of decomposing organic matter underlain by soft mud or silt. 

This species keeps a solitary life, seeking protection during daylight in aquatic plants or organic debris. Little is known about its spawning needs. It is likely, that eggs are incubated in the gill cavities in a way similar to cavefish, which also have the anus located on the throat. Small Pirate Perch have the anus located just in front of the anal fin, but the opening gradually migrates forward to the throat as the fish grows and matures.

Recent sampling information is available from Iowa DNR's biological monitoring and assessment program.

Sources:

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.

Photo credit: Photo courtesy of Konrad P. Schmidt, copyright Konrad P. Schmidt.