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NAS - Nonindigenous Aquatic Species |
Common Name: oscar
Synonyms and Other Names: velvet cichlid, red oscar, marble cichlid
Identification:
For distinguishing characteristics see Kullander (1986) and Page and Burr (1991). The genus is in need of systematic review and future study may reveal that the species in the aquarium trade and in U.S. open waters is another species of Astronotus and not A. ocellatus. Photographs were provided by Kullander (1986) and Axelrod (1993).
Size: 40 cm.
Native Range:
Genus Astronotus is native to South America including Orinoco and Amazon basins; also to French Guiana, and to northern part of Paraguay drainage, Parana basin (Kullander 1986).
This species is established in ponds, rock pits, and canals in the southern part of Florida in Broward, Collier, Dade, Glades, Hendry (possibly), Monroe, and Palm Beach counties, including portions of Everglades National Park and Big Cypress National Preserve (Rivas 1965; Courtenay et al. 1974, 1984; Hogg 1976a, 1976b; Courtenay and Hensley 1979a, 1979b; Loftus and Kushlan 1987; Courtenay and Stauffer 1990; Tilmant 1999). The species has been taken in many other Florida counties but is not known to be established. A single fish was observed in a canal in the Indian River drainage, Brevard County, on 3 July 1990 (J. Snodgrass, personal communication). Thirty-four specimens, 18.5-28 cm TL, were collected by hook and line from canals surrounding water conservation area 3A near Holiday Park, Pasco County, in or before January 1989 (USGS file record). A large specimen was taken by an angler from a river at Hontoon Island in the St. Johns River drainage, west of Orange City, Volusia County, in August 1991 (USGS file record). Records from Alachua County include a single fish taken from a pond near the town of Newberry on 27 October 1983, one fish taken from a stream on the University of Florida campus, no date given (museum specimen) and a fish taken from Green Pond on the University of Florida campus in 2001 (Hill and Cichra 2005). A large specimen, 33.7 cm TL, was taken by an angler from Boy's Club Pond in Panama City, Bay County, on 11 August 1991 (Anonymous 1993). Another fish was colledted in Lake Osborne, se coast near Lantana, Palm Beach County in 2003 (Cocking 2003). In Georgia, a single fish was taken by an angler from Gum Creek in the Flint drainage, Crisp County, on 5 June 1991; a single fish was taken by an angler from the Chattahoochee River, Fulton County, on 27 August 1989 (Gennings, personal communication). It was introduced into Hawaii in the in the 1950s on the islands of Kauai and Oahu (Brock 1960; Shima 1972; Morita 1981; Maciolek 1984; Devick 1991a, 1991b; Sakamoto 2002), water bodies stocked included Nuuanu Reservoir 2 and Wailua Reservoir on Kauai and Wahiawa Reservoir on Oahu (Brock 1960). A single fish was caught in the Kankakee River, Indiana, in 2008 (D. Keller, pers. comm.). A fish identified as Astronotus sp. reportedly was collected from an unspecified public water body in Louisiana; no date was given (Tilyou, personal communication). A single fish was taken by an angler from Congamond Lake in Southwick, Hampden County, Massachusetts, in August 1978; a sight record exists from Amherst, Hampshire County, in 1992; other unconfirmed reports from the state are known (Hartel 1992; Cardoza et al. 1993). A specimen was collected from Simley Pond, Dakota County, Minnesota (Schmidt, unpublished data). A fish was taken by hook and line in a local river in Mississippi, in 1978 (North American Native Fish Association 1978); it also has been referenced for this same state, but with no additional data, by others (e.g., Courtenay et al. 1984; Courtenay and Stauffer 1990). A single fish was collected from a pond along the North Platte River near Cozad, Nebraska, in 1998 (S. Schainost, personal communication). A single fish was caught in the Millstone River near its confluence with the Raritan River in Somerset County, New Jersey, in August 1994 (W. Wakefield, personal communication; photo). A single fish was collected in a lake near Perrysville, Ohio, in July 2000 (Kent 2000). Specimens occasionally have been collected from unspecified localities in Pennsylvania (Courtenay and Hensley 1979a; Courtenay et al. 1984, 1991; Courtenay and Stauffer 1990). It has been reported from Rhode Island (Courtenay and Hensley 1979a; Courtenay et al. 1984; Courtenay and Stauffer 1990) (the inclusion of Rhode Island is apparently based on a report, poorly documented in our files, of two specimens taken by an angler from a pond in northern part of state in the early 1970s). A single fish was taken in the Edisto River, South Carolina, in 2004 (Guerin 2004). Several Texas records are based on specimens taken by anglers, but no spawning or established populations are known (Howells 1992a). Specific Texas sites mentioned in correspondence include Victor Braunig Reservoir near San Antonio, Bexar County (Howells, personal communication), Greenbelt Reservoir, Donley County (Texas Parks and Wildlife Department. 2001), and the San Antonio River near San Antonio, Bexar County (Howells, referenced in USGS file records). They were stocked in Tradinghouse Creek Reservoir [Hallsburg, TX], Matagorda Bay, Sabine Lake (estuary), San Antonio Bay (estuary), Aransas Bay, Lower and Upper Laguna Madre, Galveston Bay, Fairfield Reservoir, Braunig Reservoir, Corpus Christi Bay in 1992 (Waldrip 1993). Specimens were collected from the following counties in Texas: Bexar, Tom Green, McLennan, Freestone, and Mitchell (Anonymous 1992; Texas Parks and Wildlife Department 1993). A single specimen was taken from a Virginia Beach, Virginia, area pond during 1987 (Jenkins and Burkhead 1994, based on Southwick, personal communication). A single fish was caught by an angler in Laek Hortonia, Rutland County, Vermont in 2005 (unknown 2005). Specimens were collected from a hydro facility trash rack at the Danbury facility on the Yellow River, Burnett County, Wisconsin (Wisconsin DNR).
A single Oscar was collected from Aibonito farm pond in southern Puerto Rico (Erdsman 1984). Reported in Puerto Rico by Lee 1983.
Ecology: Lower lethal limit is 12C (Shafland and Pestrak 1982).
Means of Introduction: The first Florida records were the result of deliberate stockings from an aquarium fish farm in southeastern Dade County in the late 1950s (Courtenay et al. 1974; Courtenay and Hensley 1979a; Courtenay and Stauffer 1990; Jackson 1999). During the same period, attempts were made to popularize the species as a sport fish under the name "velvet cichlid." Anglers have aided dispersal in Florida by transporting fish to new locations (Courtenay et al. 1974). It was sighted at the Anhinga Trail in Everglades National Park in the late 1980s (Loftus and Kushlan 1987). It apparently gained access to the park by way of the Southeast Florida Water Management District's Canal L31W, and it is now considered established (Courtenay 1989). The first introduction of this species into Hawaii was in 1952, for purposes of recreational fishing (Devick 1991a, 1991b); Hawaii's Division of Fish and Game made additional reservoir stockings in 1958; the original source of the Hawaii plants was a small stock obtained from Steinhart Aquarium in San Francisco (Brock 1960). Introductions into all other states and in more northern portions of Florida are apparently the result of aquarium releases (Courtenay and Stauffer 1990; Nico, personal communication).
Status: Established in south Florida and Hawaii. Reported from nine other states, including Georgia, Louisiana, Massachusetts, Mississippi, New Jersey, Pennsylvania, Rhode Island, Texas, and Virginia. Species established in Dade County, southeastern Florida, since late 1950s, but fish began to expand range greatly in late 1970s and early 1980s (Hogg 1976a, 1976b; Courtenay and Stauffer 1990).
Impact of Introduction: Largely unknown. In 1993, the state of Florida issued a health advisory warning people about eating freshwater fish contaminated with mercury. For portions of south Florida, the oscar was included in the list of fish affected and for which limited consumption was recommended. Oscars are considered potential competitors with native centrarchids (sunfishes) for food and spawning areas.
Remarks:
Oscars are common in the aquarium trade. Unfortunately, the taxonomy of this group is problematic and future research may determine that some oscars in the aquarium trade, as well as those taken in U.S. waters, are not A. ocellatus but another member of the genus (S. O. Kullander, personal communication). To confound the issue, artificial breeding has produced several color variants (Axelrod 1993). Oscars are considered potential competitors with native centrarchids for food and possibly for spawning areas (Courtenay and Hensley 1979a). Based on recent reports of the Florida Game and Freshwater Fish Commission, oscar now makes up a substantial proportion of the recreational fishery catch in some south Florida sectors. The Florida size record was a 1.1-kg, 32-cm TL fish taken from Lake Okeechobee, Palm Beach County, on 16 March 1994 (Ray 1994).
Voucher specimens: Florida (UF 30869, 41396, 44882, 91613, 91898, 91934); New Jersey (uncertain location).
Where introduced in
Anonymous. 1993. A new exotic state record. Florida Game and Fish, June 1993:12. Axelrod, H. R. 1993. The most complete colored lexicon of cichlids. Tropical Fish Hobbyist Publications, Inc., Neptune City, NJ.
Cardoza, J. E., G. S. Jones, T.W. French, and D. B. Halliwell. 1993. Exotic and translocated vertebrates of Massachusetts, 2nd edition. Fauna of Massachusetts Series 6. Massachusetts Division of Fisheries and Wildlife, Publication 17223-110-200-11/93-C.R, Westborough, MA.
Cocking, S. 2003. Rush to heavy-traffic area. Miami Herald. June 12, 2003.
Courtenay, W. R., Jr. 1989. Exotic fishes in the National Park System. Pages 237-252 in L. K. Thomas, editor. Proceedings of the 1986 conference on science in the national parks, volume 5. Management of exotic species in natural communities. U.S. National Park Service and George Wright Society, Washington, DC.
Courtenay, W. R., Jr., and D. A. Hensley. 1979a. Survey of introduced non-native fishes. Phase I Report. Introduced exotic fishes in North America: status 1979. Report Submitted to National Fishery Research Laboratory, U.S. Fish and Wildlife Service, Gainesville, FL.
Courtenay, W. R., Jr., and D. A. Hensley. 1979b. Range expansion in southern Florida of the introduced spotted tilapia, with comments on environmental impress. Environmental Conservation 6(2):149-151.
Courtenay, W. R., Jr., and J. R. Stauffer, Jr.. 1990. The introduced fish problem and the aquarium fish industry. Journal of the World Aquaculture Society 21(3):145-159.
Courtenay, W. R., Jr., D. A. Hensley, J. N. Taylor, and J. A. McCann. 1984. Distribution of exotic fishes in the continental United States. Pages 41-77 in W. R. Courtenay, Jr., and J. R. Stauffer, Jr., editors. Distribution, biology and management of exotic fishes. Johns Hopkins University Press, Baltimore, MD.
Courtenay, W. R., Jr., D. P. Jennings, and J. D. Williams. 1991. Appendix 2: exotic fishes. Pages 97-107 in Robins, C. R., R. M. Bailey, C. E. Bond, J. R. Brooker, E. A. Lachner, R. N. Lea, and W. B. Scott. Common and scientific names of fishes from the United States and Canada, 5th edition. American Fisheries Society Special Publication 20. American Fisheries Society, Bethesda, MD.
Courtenay, W. R., Jr., H. F. Sahlman, W. W. Miley, II, and D. J. Herrema. 1974. Exotic fishes in fresh and brackish waters of Florida. Biological Conservation 6(4):292-302.
Devick, W. S. 1991a. Disturbances and fluctuations in the Wahiawa Reservoir ecosystem. Project F-14-R-15, Job 4, Study I. Division of Aquatic Resources, Hawaii Department of Land and Natural Resources. 21 pp.
Devick, W. S. 1991b. Patterns of introductions of aquatic organisms to Hawaiian freshwater habitats. Pages 189-213 in new directions in research, management and conservation of Hawaiian freshwater stream ecosystems. Proceedings of the 1990 symposium on freshwater stream biology and fisheries management, Division of Aquatic Resources, Hawaii Department of Land and Natural Resources.
Erdsman, D.S. 1984. Exotic fishes in
Hartel, K. E. 1992. Non-native fishes known from Massachusetts freshwaters. Occasional Reports of the Museum of Comparative Zoology, Harvard University, Fish Department, Cambridge, MA. 2. September. pp. 1-9.
Hill, J. E. and C. E. Cichra. 2005. Eradication of a reproducing population of convict cichlids, Cichlasoma nigrofasciatum (Cichlidae), in north-central Florida. Florida Scientist 68: 65-74.
Hogg, R. G. 1976b. Established exotic cichlid fishes in Dade County, Florida. Florida Scientist 39(2):97-103.
Howells, R.G. - Heart of the Hills Reserach Station, TX Parks and Wildl. Dept., Ingram, TX. Response to NBS-G non-indigenous questionaire. 1992.
Howells, R. G. 1992a. Annotated list of introduced non-native fishes, mollusks, crustaceans and aquatic plants in Texas waters. Texas Parks and Wildlife Department, Management Data Series 78, Austin, TX. 19 pp. Jackson, D.C. 1999. Flathead catfish: biology, fisheries, and management. American Fisheries Society Symposium. 24: 23-36.
Jenkins, R. E., and N. M. Burkhead. 1994. Freshwater fishes of Virginia. American Fisheries Society, Bethesda, MD.
Kent, R. 2000. This fishy story is true. News Journal, Mansfield, OH. August 1.
Kullander, S.O. - Department of Vertebrate Zoology, Swedish Museum of Natural History, Stockholm, Sweden.
Kullander, S. O. 1986. Cichlid fishes of the Amazon River drainage of Peru. Swedish Museum of Natural History, Stockholm, Sweden. 431 pp.
Loftus, W. F., and J. A. Kushlan. 1987. Freshwater fishes of southern Florida. Bulletin of the Florida State Museum of Biological Science 31(4):255.
Maciolek, J. A. 1984. Exotic fishes in Hawaii and other islands of Oceania. Pages 131-161 in W. R. Courtenay, Jr., and J. R. Stauffer, Jr., editors. Distribution, biology, and management of exotic fishes. The Johns Hopkins University Press, Baltimore, MD.
Morita, C. M. 1981. Freshwater fishing in Hawaii. Division of Aquatic Resources, Department of Land and Natural Resources, Honolulu, HI. 21 pp.
North American Native Fish Association. 1978. Another threat to natives? The Lateral Line (North American Native Fish Association Newsletter, Semmes, AL), June-July, p. 1.
Page, L. M., and B. M. Burr. 1991. A field guide to freshwater fishes of North America north of Mexico. The Peterson Field Guide Series, volume 42. Houghton Mifflin Company, Boston, MA.
Ray, J. 1994. Record oscar caught in Okeechobee. Florida Wildlife 48(3):47. Rivas, L. R. 1965. Florida fresh water fishes and conservation. Quarterly Journal of the Florida Academy of Science 28(3):255-258.
Schainost, S. - Rivers and Streams Program, Nebraska Game and Parks Commission, Lincoln, NE.
Shafland, P.L. and J.M. Pestrak. 1982. Lower lethal temperatures of fourteen non-native fishes in Florida. Environmental Biology of Fishes 7(2):149-156.
Shima, C. S. 1972. Creel census and fishermen checking station operations, Statewide Dingell-Johns Program. Job Progress Report for Project F-9-2, Job 1 (Study VI). Hawaii Division of Fish and Game, Hawaii. 6 pp.
Southwick, R. - District Fisheries Supervisor, Virginia Department of Game and Inland Fisheries. Richmond, VA. Response to NBS-G non-indigenous questionaire. 1992.
Tilyou, G.A. - Inland Fish Division, Dept. of Wildlife and Fisheries, Baton Rouge, LA. Response to NBS-G nonindigenous questionaire. 1992.
Wakefield, W. - Institute of Marine and Coastal Sciences, Rutgers University, New Brunswick, NJ.
Other Resources:
Gulf of Mexico Program.
FishBase Fact Sheet
Author: Leo Nico and Pam Fuller
Revision Date: 8/29/2008 Citation for this information:
Leo Nico and Pam Fuller. 2009. Astronotus ocellatus. USGS Nonindigenous Aquatic Species Database, Gainesville, FL.
<http://nas.er.usgs.gov/queries/FactSheet.asp?speciesID=436> Revision Date: 8/29/2008
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