Margariscus margarita

Margariscus margarita
Scientific classification
Kingdom:	Animalia
Phylum:	Chordata
Class:	Actinopterygii
Order:	Cypriniformes
Family:	Cyprinidae
Genus:	Margariscus
Species:	M. margarita
Binomial name
Margariscus margarita (Cope, 1867)
Synonyms[1]
Clinostomus margarita Cope, 1867 Leuciscus carletoni Kendall, 1903 Leuciscus margarita (Cope, 1867) Semotilus margarita (Cope, 1867)

Margariscus margarita, the Pearl dace, is a species of cyprinid fish. It is demersal, freshwater fish, with a dark green back and silvery body. This species is omnivorous, consuming algae as well as arthropods. M. margarita's range spans southern Canada and the northern United States. While not considered endangered at the federal level in the United States, several states either consider this species endangered or threatened; it faces threats of habitat destruction and invasive species.

Description

Margariscus margarita is a bottom-dwelling freshwater fish that has been recorded to reach sizes of 16 centimetres (6.3 in), however, it does not commonly grow beyond about 9.3 centimetres (3.7 in). The maximum age M. margarita has been recorded to reach is four years.^[1] The body is long with small eyes and mouth.^[2] There are eight rays each in the dorsal fin, anal fin, and pelvic fins. The dorsal side is dark green in colour, with silvery flanks and a grey or white ventral side. Between late autumn and summer, males may have a brilliant orange-red stripe on the flanks, below the lateral line.^[2]

This species is omnivorous: its diet comprises algae as well as arthropods such as chironomids and water fleas. Margariscus margarita spawns in the spring.^[1] This species typically reaches sexual maturity at one year.^[2]

Distribution and habitat

Margariscus margarita inhabits North America, in southern Canada and the northern United States. It can be found in the Mississippi River, Hudson Bay, and Great Lakes. M. margarita inhabits lakes, ponds, and rivers, usually over a sandy or gravelly substrate.^[1][3] M. margarita feeds by sight,^[4] so waters it inhabits are generally clear streams and bog drainage systems.^[3]

Relationship to humans

Margariscus margarita is not considered endangered federally in the United States; however, in several states it is considered endangered or threatened. The species is uncommon in the "Great Plains" region, having declined since the region's settlement.^[4] M. margarita is threatened mainly by habitat destruction and alteration, and introduced species.^[4] Human activities such as reservoir construction, groundwater pumping, stream diversions, and channelization all contribute to the former.^[4] The introduction of exotic species such as bass, pike, or trout have an especially detrimental effect on this species. M. margarita is also caught for use as bait, which may contribute to its decline.^[4]

References

• Froese, Rainer, and Daniel Pauly, eds. (2011). "Margariscus margarita" in FishBase. August 2011 version.

1. ^ ^{a b c d} Froese, Rainer, and Daniel Pauly, eds. (2010). "Margariscus margarita" in FishBase. March 2010 version.
2. ^ ^{a b c} Bramblett, Robert G; Alexander V. Zale (June 2004). "Pearl Dace". Montana's Fish Species of Special Concern. Montana State University-Bozeman. http://www.fisheries.org/units/AFSmontana/SSCpages/Pearl%20Dace/Pearl%20Dace.htm. Retrieved 17 May 2010. 
3. ^ ^{a b} Loan-Wilsey, Anna. "Pearl dace-Margariscus margarita". Iowa Fish Atlas. http://maps.gis.iastate.edu/iris/fishatlas/IA163873.html. Retrieved 17 May 2010. 
4. ^ ^{a b c d e} Cunningham, G.R.. "Pearl Dace (Margariscus margarita): a technical conservation assessment". USDA Forest Service, Rocky Mountain Region, Species Conservation Project. USDA Forest Service. http://www.fs.fed.us/r2/projects/scp/assessments/pearldace.pdf. Retrieved 17 May 2010.