SCIENTIFIC NAME: Etheostoma nuchale
CHARACTERISTICS: The watercress darter is distinguishable from the Gulf darter, Etheostoma swaini, by having fewer pored scales in the lateral line and fewer dorsal spines and pectoral fin rays (Howell and Caldwell, 1965). Up to nine saddles cross the back and a pale stripe is usually present along the nape. Irregularly defined dark horizontal bands are formed by small spots in the center of scales along the sides. Breeding males have a reddish orange venter, fading anteriorly along the sides to a yellowish white. The caudal peduncle has up to six bluish brown vertical bars separated by poorly defined orange bars. Three distinct spots followed by large orange spots are present at the caudal fin base. The remainder of the caudal fin is blue around the spots and clear. The anal fin is bright blue, and the paired fins are lighter blue, fading to clear at the margins. Both the spiny and soft dorsal fins have four distinct color bands, from outside to inside: blue, reddish orange, blue, and red.
ADULT SIZE: 1 to 1.8 in (25 to 45 mm)
DISTRIBUTION: The watercress darter is restricted to three spring areas in the Black Warrior River system.
HABITAT AND BIOLOGY: Individuals of this species are found at mid-depths in dense accumulations of aquatic vegetation including watercress, Chara, and Spirogyra in deep, slow-moving backwaters of springs (Howell et al., 1980). Dense populations of aquatic insect larvae and microcrustaceans that thrive in these springs provide abundant food for watercress darters. The protracted spawning season, lasting from March through July, is likely related to the constant 62º to 65ºF (16º to 18ºC) water temperatures found in the springs. Surveys by Moss (1995) reveal that populations appear healthy, but that nonpoint urban runoff is a continuing threat to water quality of the springs.
REMARKS: The type locality for the watercress darter is a spring tributary to Valley Creek, Jefferson County, Alabama. The watercress darter is listed as an endangered species by the U.S. Fish and Wildlife Service.
ORIGINAL DESCRIPTION: Howell and Caldwell described the watercress darter in 1965.
Etheostoma means strain mouth, possibly referring to the small mouth.
Nuchale from nucha, meaning nape or back of the neck, in reference to the humped nape of breeding males.
The copyrighted information above is from Fishes of Alabama and the Mobile Basin.