About Percina aurantiaca (Cope, 1868)
The tangerine darter, also called the river slick, has the scientific name Percina aurantiaca. It is a small species of freshwater ray-finned fish, classified as a darter in the subfamily Etheostomatinae, part of the family Percidae that also includes perches, ruffes, and pikeperches. This species grows between 4.3 to 7.1 inches, or 11 to 18 cm, long; mature males are bright orange-red, while females are yellow. It is an insectivorous species that feeds by picking insect larvae off aquatic plants and the riverbed, and will sometimes roll small stones over to uncover hidden prey. It breeds in late spring and early summer, usually in shallow sandy or gravelly riffles. While pollution and habitat degradation threaten the species in parts of its range, it is fairly common and has a wide distribution, so the International Union for Conservation of Nature has classified its conservation status as Least Concern. This is a fairly common darter, but its range is restricted to clear, cool streams of the southern Appalachian Mountains. It occurs throughout the mountainous regions of the upper Tennessee River drainage, inhabiting smaller rivers, and is most abundant in the Emory, Hiwassee, Little, Little Pigeon, and Tellico rivers. It can be found in eastern Tennessee, northern Georgia, western North Carolina, and Virginia. In Georgia and North Carolina, it is listed as a historic species that requires management. The tangerine darter lives in clear, cool creeks and small rivers, where it favors areas with large boulders, bedrock, and gravel substrate, and prefers to swim in the deeper riffles of these waterways. During winter, the species moves into deeper pools. Spawning takes place from late spring to summer, in shallow sandy-gravel riffles with steady flowing water. The breeding season is triggered by water temperature, and runs from May through July. Spawning occurs when individuals are three to four years old, though the species reaches sexual maturity earlier: males mature at one year of age, and females mature at two years of age. The typical lifespan of the tangerine darter is around four years. During spawning, the male first mounts the female. The female then scatters her eggs across the gravel, while the male releases milt to fertilize the eggs; both the male and female make quivering motions throughout this process. Females select the most brightly colored males, which have bright orange bodies with a black line and some blue coloring where the orange meets the black. Males become territorial during the mating season and will defend their spawning riffles. A single female can lay between 120 and 1,100 eggs, and this species does not provide any parental care for its eggs. Juvenile tangerine darters live in calmer water, and grow to between 2 and 3 inches, or 5.1 and 7.6 cm, long during their first year of growth.
