Disclaimer:

The Nonindigenous Occurrences section of the NAS species profiles has a new structure. The section is now dynamically updated from the NAS database to ensure that it contains the most current and accurate information. Occurrences are summarized in Table 1, alphabetically by state, with years of earliest and most recent observations, and the tally and names of drainages where the species was observed. The table contains hyperlinks to collections tables of specimens based on the states, years, and drainages selected. References to specimens that were not obtained through sighting reports and personal communications are found through the hyperlink in the Table 1 caption or through the individual specimens linked in the collections tables.

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Common name: Guaru

Taxonomy: 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).

Alaska	Hawaii	Puerto Rico & Virgin Islands	Guam Saipan

Hydrologic Unit Codes (HUCs) Explained
Interactive maps: Point Distribution Maps

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.

Other Resources:
US Fish and Wildlife Service Ecological Risk Screening Summary for Poecilia vivipara

Author: Neilson, M.E.

Peer Review Date: 8/26/2011

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.