Sicklefin chub

Sicklefin chub
Scientific classification
Kingdom: Animalia
Phylum: Chordata
Class: Actinopterygii
Order: Cypriniformes
Family: Cyprinidae
Genus: Macrhybopsis
Species: M. meeki
Binomial name
Macrhybopsis meeki
(D. S. Jordan & Evermann, 1896)

The sicklefin chub (Macrhybopsis meeki) is a species of ray-finned minnow fish in the Cyprinidae family. 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.[1]

Names and documentation

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.[2] They named it Hybopsis meeki.[2] The name meeki is in honor of Seth Eugene Meek, a noted American fish biologist.[3] 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.[2]

Description and habitat

The sicklefin chub is a small fish which can reach 4.25 inches (10.8 cm) in adulthood.[4] The snout is round and bulbous, and overhangs the lower jaw slightly.[3] 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.[3][4] Its head is wide and deep, flat on top, with eyes set high on the head.[2][4] The eyes are not as high on the head as in similar species, and are sometimes covered with a flap of skin.[3] There is a small barbel near the corner of the mouth,[4] and small pustules on the throat.[2] Unlike the sturgeon chub, which it closely resembles, the sicklefin chub has no "keels" (small ridge-like protrusions on its scales).[4] This fish has silvery sides, and is light green or brown on top.[4] The fish often exhibits dark brown or silver specks.[4] In larger individuals, the lower lobe of the caudal fin is often black with a white edge.[5] This fish has large, pointed, sickel-shaped fins, which gives the minnow its name.[6] The dorsal fin originates just over or behind where the pelvic fin originates.[4] 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.[6] There are eight rays in the anal fin.[4] The chest and belly of the fish lack scales, but not the sides or tail.[3]

Little is known about its feeding habits,[2] although it does have teeth in its throat.[4] Black fly pupae and other insects have been found in the stomachs of some specimens.[7] There is some evidence that it is a bottom feeder.[8][9] The eyes are weak and it does not see well.[10] Its body, however, is covered with taste buds which help it locate food.[10] 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.[9]

Almost nothing is known about its breeding habits,[2] but it is an egg layer.[8] The sicklefin chub exhibits little sexual dimorphism, and neither sex exhibits color changes during breeding.[3] However, the male develops small tubercles on the fin rays during breeding.[3] Breeding probably occurs in the spring,[7][11] and the fish is thought to be quite short-lived.[11]

The sickelfin chub lives in fast-moving rivers with sandy or fine gravel beds,[2] but is more commonly found on sandy beds.[7] 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.[4] It is fairly common in the Missouri River, but rare elsewhere.[4] It has also been reported in the lower Kansas River.[7]

Dams have destroyed much of the sickelfin chub's habitat by slowing currents and allowing silt to precipitate from the water and cover the sand and gravel beds the fish prefers.[12] 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 sickelfin chub as a threatened species, but declined to do so.[14]

References

  1. ↑ U.S. Fish and Wildlife Service. Draft Comprehensive Conservation Plan and Environmental Impact Statement: Charles M. Russell National Wildlife Refuge and UL Bend National Wildlife Refuge, Montana. U.S. Department of the Interior. September 2010, p. 60. Accessed 2012-04-27.
  2. 1 2 3 4 5 6 7 8 Smith, Philip Wayne. The Fishes of Illinois. Chicago: University of Illinois Press, 2002, p. 80.
  3. 1 2 3 4 5 6 7 Ross, Stephen T. and Brenneman, William M. The Inland Fishes of Mississippi. Jackson, Miss.: University Press of Mississippi, 2001, p. 179.
  4. 1 2 3 4 5 6 7 8 9 10 11 12 Page, Lawrence M. and Burr, Brooks. Peterson Field Guide to Freshwater Fishes of North America North of Mexico. Boston: Houghton Mifflin Harcourt, 2011, p. 104.
  5. ↑ Page, Lawrence M. and Burr, Brooks. Peterson Field Guide to Freshwater Fishes of North America North of Mexico. Boston: Houghton Mifflin Harcourt, 2011, p. 103-104.
  6. 1 2 Page, Lawrence M. and Burr, Brooks. Peterson Field Guide to Freshwater Fishes of North America North of Mexico. Boston: Houghton Mifflin Harcourt, 2011, p. 103.
  7. 1 2 3 4 Ross and Brenneman, p. 180.
  8. 1 2 Marshall Cavendish Corporation. Endangered Wildlife of the World. New York: Marshall Cavendish, 1993, p. 204.
  9. 1 2 Pflieger, William L. and Smith, Pat. The Fishes of Missouri. Jefferson City, Mo.: Missouri Department of Conservation, 1997, p. 12.
  10. 1 2 Savage, Candace. Prairie: A Natural History. Vancouver, B.C.: Greystone Books, 2011, p. 180.
  11. 1 2 Stukel, E.D. "Sturgeon and Sicklefin Chubs." South Dakota Conservation Digest. May/June 2001, p. 24.
  12. ↑ Polis, Gary A.; Power, Mary E.; and Huxel, Gary R. Food Webs at the Landscape Level. Chicago: University of Chicago Press, 2004, p. 424.
  13. ↑ Stukel, E.D. "Sturgeon and Sicklefin Chubs." South Dakota Conservation Digest. May/June 2001, p. 25.
  14. ↑ Hildebrand, Stephen G. and Cannon, Johnnie B. Environmental Analysis: The NEPA Experience. New York: CRC Press, 1993, p. 133.

Further reading

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