Common name: Guaru
available through www.itis.gov
Identification: Identifying features given in Hildebrand (1935) and Smith (1997).
Size: males to 4.0 cm TL; females to 5.0 cm TL
Native Range: South America, Venezuela to Argentina (Smith 1997).
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 Poecilia vivipara are found here.
Table last updated 12/11/2023
† Populations may not be currently present.
Ecology: Occurs in brackish to fresh water canals, drainage ditches, upland stream, and swamps (Hildebrand 1935).
Means of Introduction: Myers (1938) suggested that P. vivipara was introduced to Puerto Rico by humans, or less likely through colonization from South America.
Status: Established in Puerto Rico.
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)
Hildebrand, S.F. 1935. An annotated list of the fishes of the fresh waters of Puerto Rico. Copeia 1935:49-56.
Myers, G.S. 1938. Fresh-water fishes and West Indian zoogeography. Annual Report of the Board of Regents of the Smithsonian Institution 92:339-364
Smith, C.L. 1997. National Audubon Society field guide to tropical marine fishes of the Caribbean, the Gulf of Mexico, Florida, the Bahamas, and Bermuda. Alfred A. Knopf, Inc., New York, NY.
Revision Date: 6/29/2023
Peer Review Date: 8/26/2011
Neilson, M.E., 2023, Poecilia vivipara Bloch and Schneider, 1801: U.S. Geological Survey, Nonindigenous Aquatic Species Database, Gainesville, FL, https://nas.er.usgs.gov/queries/FactSheet.aspx?speciesID=2639, Revision Date: 6/29/2023, Peer Review Date: 8/26/2011, Access Date: 12/11/2023
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.