Common name: black tetra
Synonyms and Other Names: Tetragonopterus ternetzi Boulenger, 1895
available through www.itis.gov
Identification: Géry (1977) provided an identification key and color photographs. Color photographs were also provided in Axelrod et al. (1985) and Sakurai et al. (1993).
Size: 5-7.5 cm SL
Native Range: Tropical America. Amazon (Guaporé drainage) and La Plata (Paraguay River) basins in southern Brazil, Argentina, and Bolivia, South America (Géry 1977).
Hydrologic Unit Codes (HUCs) Explained
Puerto Rico &
Interactive maps: Point Distribution Maps
Table 1. States with nonindigenous occurrences, the earliest and latest observations in each state, and the tally and names of HUCs with observations†. Names and dates are hyperlinked to their relevant specimen records. The list of references for all nonindigenous occurrences of Gymnocorymbus ternetzi are found here.
Table last updated 2/27/2023
† Populations may not be currently present.
Means of Introduction: The Colorado introduction resulted from an escape from a local tropical fish farm, and the Florida record may represent either an aquarium release or a fish farm escape. The Louisiana collection took place near a tropical fish farm and was likely and escapee.
Status: Failed in Colorado, Florida, and Louisiana.
Impact of Introduction: The impacts of this species are currently unknown, as no studies have been done to determine how it has affected ecosystems in the invaded range. The absence of data does not equate to lack of effects. It does, however, mean that research is required to evaluate effects before conclusions can be made.
References: (click for full references)
Axelrod, H.R., W.E. Burgess, N. Pronek, and J.G. Walls. 1985. Dr. Axelrod's atlas of freshwater aquarium fishes. Tropical Fish Hobbyist Publications, Inc., Neptune City, NJ.
Courtenay, W.R., Jr., and D.A. Hensley. 1979. 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.
Géry, J. 1977. Characoids of the world. Tropical Fish Hobbyist Publications, Inc., Neptune City, NJ.
Piller, K. - Southeastern Louisiana University.
Zuckerman, L. - Aquatic Ecologist, Kansas Department of Wildlife and Parks, Pratt, KS.
Zuckerman, L.D., and R.J. Behnke. 1986. Introduced fishes in the San Luis Valley, Colorado. Pages 435-452 in R.H. Stroud, ed. Fish culture in fisheries management. Proceedings of a symposium on the role of fish culture in fisheries management at Lake Ozark, MO, March 31-April 3, 1985. American Fisheries Society, Bethesda, MD.
Leo Nico, and Pam Fuller
Revision Date: 1/31/2005
Peer Review Date: 1/31/2005
Leo Nico, and Pam Fuller, 2023, Gymnocorymbus ternetzi (Boulenger, 1895): U.S. Geological Survey, Nonindigenous Aquatic Species Database, Gainesville, FL, https://nas.er.usgs.gov/queries/FactSheet.aspx?SpeciesID=420, Revision Date: 1/31/2005, Peer Review Date: 1/31/2005, Access Date: 3/24/2023
This information is preliminary or provisional and is subject to revision. It is being provided to meet the need for timely best science. The information has not received final approval by the U.S. Geological Survey (USGS) and is provided on the condition that neither the USGS nor the U.S. Government shall be held liable for any damages resulting from the authorized or unauthorized use of the information.