SCIENTIFIC NAME: Etheostoma swaini
CHARACTERISTICS: The Gulf darter is known for its laterally compressed, robust body with small conical head, slightly joined gill membranes, and a wide frenum on its upper lip. The back has seven to nine diffuse, square saddles and a distinctive light predorsal stripe. Horizontal light and dark banding is evident along the sides. Along their sides breeding males have alternating red-orange and blue-green vertical bars that are developed best near the caudal fin. The venter is orange. The spiny dorsal fin has a red band near its base, above which is a blue band, then another red band, and finally a light blue to clear band at its free margin. The anal fin and base of the pelvic fins are blue; other fins are generally clear. A large, black spot is present at the base of the pectoral fin and three diffuse spots occur at the caudal fin base. The caudal fin has diffuse, wavy black bands. Etheostoma swaini is most similar to the watercress darter, E. nuchale, and coldwater darter, E. ditrema, both of which have fewer pored lateral line scales. See Jordan (1884b) for original description.
ADULT SIZE: 1.8 to 2.4 in (45 to 60 mm)
DISTRIBUTION: Etheostoma swaini is predominantly a lowland species. Most of our collection records in the Mobile basin are from either below or short distances above the Fall Line. Northward extensions occur in western tributaries to the Coosa River system in Chilton and Shelby counties, and a single record exists for the Cahaba River in Jefferson County. This species is also found in coastal drainages of Alabama from the Escatawpa River east to the Chipola River, a tributary to the Apalachicola River.
HABITAT AND BIOLOGY: Gulf darters are found in riffles, fast-flowing areas of clear streams, and small rivers over gravel, cobble, debris snags, clay stone, and rubble at bridge crossings. Almost any material that provides cover in suitable current serves as a preferred habitat for this species. The Gulf darter is often associated with vegetation. Spawning occurs from mid-March to late April or early May.
ORIGINAL DESCRIPTION: Jordan described the Gulf darter in 1884.
Etheostoma means strain mouth, possibly referring to the small mouth.
Swaini is in honor of Joseph Swain, a 19th-century ichthyologist.
The copyrighted information above is from Fishes of Alabama and the Mobile Basin.