Sicklefin chub | |
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Scientific classification ![]() | |
Domain: | Eukaryota |
Kingdom: | Animalia |
Phylum: | Chordata |
Class: | Actinopterygii |
Order: | Cypriniformes |
Family: | Leuciscidae |
Genus: | Macrhybopsis |
Species: | M. meeki |
Binomial name | |
Macrhybopsis meeki (D. S. Jordan & Evermann, 1896) | |
Synonyms [2] | |
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The sicklefin chub (Macrhybopsis meeki) is a species of freshwater ray-finned fish belonging to the family Leuciscidae, the shiners, daces and minnows. [2] It is found only in the United States. It is one of the 324 fish species found in Tennessee, and is a species of concern in the Charles M. Russell National Wildlife Refuge in Montana. [3]
The type species was collected in the Missouri River near St. Louis, Missouri, and described by David Starr Jordan and Barton Warren Evermann in 1896. [4] They named it Hybopsis meeki. [4] The name meeki is in honor of Seth Eugene Meek, a noted American fish biologist. [5] In 1908, Stephen Alfred Forbes and Robert Earl Richardson suggested the binomial name Platygobio gracilis based on a specimen collected in Illinois, but this is clearly the same species described by Jordan and Evermann. [4]
The sicklefin chub is a small fish which can reach 4.25 inches (10.8 cm) in adulthood. [6] The snout is round and bulbous, and overhangs the lower jaw slightly. [5] It is fairly round and thickest around the nape (the area just in back of the head), and the body tapers significantly until it reaches the tail. [5] [6] Its head is wide and deep, flat on top, with eyes set high on the head. [4] [6] The eyes are not as high on the head as in similar species, and are sometimes covered with a flap of skin. [5] There is a small barbel near the corner of the mouth, [6] and small pustules on the throat. [4] Unlike the sturgeon chub, which it closely resembles, the sicklefin chub has no "keels" (small ridge-like protrusions on its scales). [6] This fish has silvery sides, and is light green or brown on top. [6] The fish often exhibits dark brown or silver specks. [6] In larger individuals, the lower lobe of the caudal fin is often black with a white edge. [7] This fish has large, pointed, sickle-shaped fins, which gives the minnow its name. [8] The dorsal fin originates just over or behind where the pelvic fin originates. [6] When depressed, the first dorsal fin extends beyond the last ray. The tip of the pelvic fin can reach beyond the origin of the pelvic fin. [8] There are eight rays in the anal fin. [6] The chest and belly of the fish lack scales, but not the sides or tail. [5]
Little is known about its feeding habits, [4] although it does have teeth in its throat. [6] Black fly pupae and other insects have been found in the stomachs of some specimens. [9] There is some evidence that it is a bottom feeder. [10] [11] The eyes are weak and it does not see well. [12] Its body, however, is covered with taste buds which help it locate food. [12] There are also taste buds in the mouth, which has led to speculation that the fish sorts food orally and spits out what is not edible. [11]
Almost nothing is known about its breeding habits, [4] but it is an egg layer. [10] The sicklefin chub exhibits little sexual dimorphism, and neither sex exhibits color changes during breeding. [5] However, the male develops small tubercles on the fin rays during breeding. [5] Breeding probably occurs in the spring, [9] [13] and the fish is thought to be quite short-lived. [13]
The sicklefin chub lives in fast-moving rivers with sandy or fine gravel beds, [4] but is more commonly found on sandy beds. [9] Its range covers the entire Missouri River; the Mississippi River from the mouth of the Missouri River down to the Ohio River; and the Mississippi River in southern Mississippi and northern Louisiana. [6] It is fairly common in the Missouri River, but rare elsewhere. [6] It has also been reported in the lower Kansas River. [9]
Dams have destroyed much of the sicklefin chub's habitat by slowing currents and allowing silt to precipitate from the water and cover the sand and gravel beds the fish prefers. [14] The United States Fish and Wildlife Service (FWS) estimated in 2001 that it only inhabited about 54 percent of its former range. [13] In 1993, the FWS considered listing the sicklefin chub as a threatened species, but declined to do so. [15]