The Cape Fear shiner (Notropis mekistocholas) is a North American species of freshwater fish in the family Cyprinidae. It is endemic to the central part of the state of North Carolina in the southeastern United States, and is only found in the shallow streams of the Cape Fear River basin. The fish is small and yellow with black lips and a black stripe that runs down the middle of the fish's side. This shiner is normally found in mixed schools with other minnow species. It is unique amongst its genus because it has elongated intestines that are specifically adapted to a primarily herbivorous diet. It can breed twice a year and normally lives for only two or three years in the wild. The males and females are normally similar in appearance but become different colors in the spawning season. This species of shiner was not discovered until 1962.
As of 2013, the shiner is endangered, according to the International Union for Conservation of Nature, due to its small population size and threats to its habitat from dam construction and pollution. It was previously listed as critically endangered by the IUCN in 1996. The species has since undergone a successful captive breeding program, and its status has been a significant factor in the destruction of a dam that destroyed part of the shiner's habitat. However, the species is still limited to just five populations in the wild, and some experts believe that a single toxic chemical spill into the Cape Fear River could wipe out the entire wild population.
Taxonomy
The Cape Fear shiner was only discovered in 1962 and described as a distinct species by Franklin F. Snelson Jr. in 1971. The specific epithet is derived from the Greek mēkistos/μηκιστος - 'longest/tallest' or 'very long' (a superlative from mēkos/μηκος - length) and...cholas/χολας 'intestines' or 'bile'. This fish belongs to the carp and minnow family Cyprinidae, and within this family, it belongs to the genus Notropis, which includes a large number of eastern North American minnows. The Cape Fear shiner is unusual in its genus because its intestines are elongated and more convoluted than those of other Notropis species, a trait shared only by the Ozark Minnow. This feature better adapts the shiner to a diet primarily of plant material. It is superficially different from similar members of its genus because of the angle and size of its mouth, head shape, eight anal fin rays, and black edge on its lower lip. It is also one of the few Notropis to have a black peritoneum. Its closest relatives are the Swallowtail Shiner and the Sand Shiner. It has no subspecies.
Description
The Cape Fear shiner is a small but stocky minnow of about 5 centimeters (2 in) long with a maximum length of 7.7 centimeters (3 in). It is mostly a silvery yellowish shade with a black stripe running down the middle of the fish's side to its caudal peduncle and a lighter stripe above this one. The scales are outlined in black. The shiner's fins are clear to yellow and moderately pointed. The dorsal fin's origin is over or slightly before the pelvic fin's origin. During the spawning season, the males become more golden in color while the females become more silvery. The Cape Fear Shiner's snout is acute and rounded and has a black upper lip and a lower lip that has a thin black bar stretching across its margin. The upper lip always overhangs above the lower lip.
The shiner only has pharyngeal teeth (teeth located on the back of the fish's throat on its gill arches), similar to the teeth of other omnivorous shiners. The Cape Fear Shiner's eyes are moderately sized and on the side of the fish's head. It has eight anal fin rays. The shiner's distinctive long dark intestines are coiled and visible through the fish's belly wall and it also has a distinctive black peritoneum.
Distribution and habitat
The Cape Fear shiner is endemic to the Upper Basin of the Cape Fear River in North Carolina’s Piedmont. Only five wild populations of this fish are known to exist. These populations are found in the freshwater Deep, Haw, and Rocky rivers in Chatham, Harnett, Lee, Moore, and Randolph counties. The largest of these populations is found where the Deep and Rocky Rivers meet. During the winter, shiners may migrate from their shoals in main river channels to smaller tributary streams. This shiner has the smallest range of any Notropis.
This minnow typically lives in clean streams over gravel, cobble, and boulder substrates, especially where nearby water willows and riverweed are available to provide protection from predators. The shiner rarely ventures into water deeper than 0.5 meters (1.6 ft). It has been observed in slow runs, riffles, and slow pools.