Etheostoma gracile (Girard, 1859)

Common Name and Taxonomic Classification

Etheostoma gracile, commonly known as the slough darter, is a small ray-finned fish species. It is a darter belonging to the subfamily Etheostomatinae, which is part of the family Percidae — a group that also includes perches, ruffs, and pike-perches.

Habitat Flow and Substrate

This species lives in slow to moderately flowing waters with substrates that are mostly made up of mud, silt, or sand.

Diet Composition

Its main food sources are chironomids, copepods, and cladocerans, with mayflies also forming part of its diet in the spring.

Adult Size

Adult slough darters reach a total length of 35 to 50 mm, which is 1.4 to 2.0 inches.

Regional Occurrence

It is counted among the 324 fish species found in Tennessee.

Breeding Period Variation

Breeding times for the slough darter vary by location: at the southern end of its range in Texas, breeding occurs from January to March, while at the northern end of its range in Illinois, breeding takes place in May and June.

Egg Laying Characteristics

The species lays its eggs, which attach to submerged vegetation, leaves, or twigs. Unlike some other members of the Percidae family, adult slough darters do not guard their eggs.

Mississippi River Basin Distribution

The distribution of Etheostoma gracile covers the Mississippi River basin from central Illinois and northeastern Missouri down to Louisiana.

Additional Drainage Distribution

It is also found in Red River drainages extending into southeastern Kansas and eastern Oklahoma, and in Gulf Slope drainages ranging from the Tombigbee River in Mississippi to the Nueces River in Texas.

Suitable Habitat Types

Suitable habitats for the slough darter include slow-flowing pools in small streams, backwaters of larger rivers, turbid water over sand or mud, oxbow lakes, swamps, and areas among aquatic vegetation.