ROCK DARTER
SCIENTIFIC NAME: Etheostoma rupestre
CHARACTERISTICS: The rock darter has large pectoral fins, broadly joined gill membranes that form a shallow V, a moderately blunt snout, a slightly inferior mouth, and a frenum. The back and upper sides are brownish green with six brown blotches on the back and six to nine variously developed green V- or W-shaped blotches or vertical bars with brown edging along the sides. The most posterior bars are green and may encircle the caudal peduncle. Orbital bars are well developed. Breeding males are dark green with a base body color of tan to light brown. Both dorsal fins have green margins, clear median bands, and brown basal bands. The head is entirely green, and the back is green around slightly diffused saddles. Pelvic, anal, and pectoral fins are green, fading to clear at their tips. The caudal fin is green with two to four light tan medial spots at its base. See Gilbert (1887) for original description.
ADULT SIZE: 1.8 to 2.8 in (45 to 70 mm)
DISTRIBUTION: Most collection records of this Mobile basin endemic are from below the Fall Line in the Tombigbee and lower Alabama river drainages. Rock darters are particularly abundant above and below the Fall Line in the Cahaba River system. Isolated populations are known in the upper Coosa River system in Georgia and Tennessee, Hatchet Creek in the lower Coosa, and Uphapee Creek in the lower Tallapoosa.
HABITAT AND BIOLOGY: Etheostoma rupestre is generally confined to riffle habitats containing gravel, cobble, and rubble in moderate to large rivers and streams. It is generally absent when these habitats are unavailable. Artificial rubble and riprap occasionally left in streams during bridge construction provide excellent habitat for rock darters. Individuals are usually uncommon in small woodland streams. Spawning occurs from March to early May. The diet of this and many other riffle-dwelling darters is composed of aquatic insect larvae.
REMARKS: The type locality for the rock darter is the North River near Tuscaloosa, Tuscaloosa County, Alabama.
ORIGINAL DESCRIPTION: Gilbert and Swain described the rock darter in 1887.
ETYMOLOGY:
Etheostoma means strain mouth, possibly referring to the small mouth.
Rupestre means living among the rocks.
The copyrighted information above is from Fishes of Alabama and the Mobile Basin.
