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.

Megalops atlanticus
Megalops atlanticus
Marine Fishes
Native Transplant

Copyright Info
Megalops atlanticus Valenciennes in Cuvier and Valenciennes, 1847

Common name: Tarpon

Taxonomy: available through www.itis.govITIS logo

Identification: Hoese and Moore (1998); Manooch (1984); Robins and Ray (1986); Murdy et al. (1997).

Size: 2.4 meters

Native Range: Marine and estuarine. Virginia (occasionally Nova Scotia), Bermuda, and Gulf of Mexico to Brazil; also eastern Atlantic; occasional near Pacific terminus of Panama Canal (Robins and Ray 1986). Murdy et al. (1997) reported this species occasionally gets as far north as Chesapeake Bay, Maryland, as a result of seasonal movement via the Gulf Stream.

Interactive maps: Point Distribution Maps

Nonindigenous Occurrences:

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 Megalops atlanticus are found here.

StateFirst ObservedLast ObservedTotal HUCs with observations†HUCs with observations†
TX195019892East Galveston Bay; Upper San Antonio

Table last updated 2/24/2024

† Populations may not be currently present.

Means of Introduction: A subset of the Tarpon used in cold tolerance studies were introduced into the Victor Braunig Reservoir in Texas following the experiment (Howells and Garrett 1992).

Status: Likely extirpated, as no tarpon have been reported since 1989 when at least one individual was found dead in Victor Braunig Reservoir after an extreme cold event (Howells and Garrett 1992). Some of the released tarpon may have survived in the Reservoir, but it is unlikely that they are capable of spawning in the freshwater impoundment (Howells and Garrett 1992).

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.

Remarks: A dead Tarpon that was recoved in Victor Braunig Reservoir, Texas, contained multiple Blue Tilapia (Oreochromis aureus) in its stomach (Howells and Garrett 1992). 

References: (click for full references)

Hoese, H.D., and R.H. Moore. 1998. Fishes of the Gulf of Mexico. Texas, Louisiana, and adjacent waters. 2nd edition. Texas A&M University Press. College Station, TX.

Howells, R.G., and G.P. Garrett. 1992. Status of some exotic sport fishes in Texas waters. Texas Journal of Science 44(3):317-324.

Manooch, C.S. 1984. Fisherman's guide, fishes of the southwestern United States. North Carolina State Museum of Natural History, Raleigh, NC.

Murdy, E.O., R.S. Birdsong, and J.A. Musick. 1997. Fishes of Chesapeake Bay. Smithsonian Institution Press, Washington, DC.

Robins, C. R., and G. C. Ray. 1986. A field guide to Atlantic Coast fishes of North America. The Peterson Guide Series, volume 32. Houghton Mifflin Company, Boston, MA.

Other Resources:
FishBase Summary

Author: Fuller, P., Neilson, M., and Procopio, J.

Revision Date: 3/3/2020

Peer Review Date: 1/31/2012

Citation Information:
Fuller, P., Neilson, M., and Procopio, J., 2024, Megalops atlanticus Valenciennes in Cuvier and Valenciennes, 1847: U.S. Geological Survey, Nonindigenous Aquatic Species Database, Gainesville, FL, https://nas.er.usgs.gov/queries/FactSheet.aspx?SpeciesID=775, Revision Date: 3/3/2020, Peer Review Date: 1/31/2012, Access Date: 2/24/2024

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.


The data represented on this site vary in accuracy, scale, completeness, extent of coverage and origin. It is the user's responsibility to use these data consistent with their intended purpose and within stated limitations. We highly recommend reviewing metadata files prior to interpreting these data.

Citation information: U.S. Geological Survey. [2024]. Nonindigenous Aquatic Species Database. Gainesville, Florida. Accessed [2/24/2024].

Contact us if you are using data from this site for a publication to make sure the data are being used appropriately and for potential co-authorship if warranted.

For general information and questions about the database, contact Wesley Daniel. For problems and technical issues, contact Matthew Neilson.