Sheepshead minnow 



Cyprinodon variegatus 

 Adult 



(from Jordan 1925) 



Common Name: sheepshead minnow 



Scientific Name: Cyprinodon variegatus 



Other Common Names: Variegated minnow 



(Hildebrand 1919); sheepshead killifish (Harrington 



and Harrington 1 961 ); sheepshead pupfish (Blair et al. 



1968); broad killifish, and chubby (Breuer 1957). 



Classification (Robins et al. 1991) 



Phylum: Chordata 



Class: Osteichthyes 



Order: Atheriniformes 



Family: Cyprinodontidae 



Value 



Commercial : This fish has some commercial value as 

 bait (Simpson and Gunter 1956, Perschbacher and 

 Strawn 1986), but little information is available on its 

 use. 



Recreational : This species' recreational value is lim- 

 ited to its use as bait by anglers, and as a forage for 

 game fish species. In addition, it is occasionally kept as 

 an aquarium fish. 



Indicator of Environmental Stress : The sheepshead 

 minnow is used extensively as a bioassay organism by 

 U.S. Environmental Protection Agency (EPA) and oth- 

 ers for acute, partial-chronic, and chronic bioassays in 

 order to set water quality standards. Testing is prima- 

 rily for effects of organochlorides and organophospho- 

 rus compounds on the estuarine community, but this 

 species is also useful in the evaluation of the 

 hepatocarcinogenic risks of chemicals in contami- 

 nated coastal waters (Schimmel et al. 1 974, Schimmel 

 and Hansen 1974, Goodman et al. 1979, Karara and 

 Hayton 1984, Couch and Courtney 1987, Hale 1989, 

 Hutchinson and Williams 1989, Miller et al. 1990). 



Ecological : The sheepshead minnow and other 

 cyprinodontids are important in the control of salt water 

 mosquitoes (Hildebrand 1919, Harrington and 

 Harrington 1 961 ) and also in the export of energy from 

 the marsh by serving as food for birds and larger fish 

 (Hildebrand 1919, Simmons 1957, Perschbacher and 

 Strawn 1986). Burrowing behavior by this and other 

 species of marsh fish during cold weather may ad- 

 versely affect nesting success of wading birds by 

 making these fish less available to avian predation 

 (Frederick and Loftus 1 993). The sheepshead minnow 

 is able to thrive in marginal shallow water habitats, and 

 therefore utilizes areas devoid of other fish species 

 (Shipp1986). 



Range 



Overall : The range for this species extends along the 

 Atlantic coast, from Maine to Yucatan, Mexico, and 

 throughout the West Indies to northern South America 

 (Blair et al. 1 968, Hoese and Moore 1 977, Hardy 1 978, 

 Leeetal. 1980). 



Within Study Area : Within U.S. Gulf of Mexico estuar- 

 ies, this fish can be found from the Rio Grande, Texas, 

 to Florida Bay, Florida (Table 5.22) (Odum and Caldwell 

 1955, Springer and Woodburn 1960, Tabb and Man- 

 ning 1 961 , Finucane 1 966, Moe et al. 1 966, Blair et al. 

 1 968, Wang and Raney 1 971 , Hoese and Moore 1 977, 

 Hardy 1978, Lee et al. 1980). 



Life Mode 



Eggs are demersal (Kuntz 1914, Schimmel and Hansen 

 1974, Hardy 1978). Larvae, juveniles, and adults are 

 markedly diurnal (Breder 1959, Ruebsamen 1972). 

 They have been observed to school, especially when 

 frightened (Hildebrand and Schroeder 1928, Martin 



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