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.

Apalone ferox
Apalone ferox
(Florida Softshell)
Native Transplant

Copyright Info
Apalone ferox (Schneider, 1783)

Common name: Florida Softshell

Taxonomy: available through www.itis.govITIS logo

Identification: Like most trionychids (softshells), Apalone ferox lacks a hard shell and has a greatly flattened body (Behler and King, 1979; Conant and Collins, 1998; Powell et al., 1998). Apalone ferox can be distinguished from other Apalone by a combination of lateral ridges projecting from the nasal septem into the nostrils, and more than one row of flattened tubercles along the anterior edge of the carapace (upper shell) (Ernst et al., 1994; Conant and Collins, 1998; Powell et al., 1998). The carapace of Florida Softshells tends to be more oblong, lengthwise than other softshells (Ashton and Ashton, 1991; Conant and Collins, 1998). Juveniles may have an orange stripe on the head, behind the eye, and a spotted carapace bordered in orange (Ashton and Ashton, 1991; Ernst et al., 1994; Conant and Collins, 1994). Adult A. ferox have a carapace length of 152-626 mm (6-24.75 in), and are the largest and heaviest of all North American Apalone (Conant and Collins, 1998). Florida Softshells have been illustrated by numerous authorities (Pope, 1939; Carr, 1952; Ernst and Barbour, 1972, 1989; Mount, 1975; Behler and King, 1979; Pritchard, 1979; Martof et al., 1980; Smith and Brodie, 1982; Obst, 1986; Meylan, 1987; Ashton and Ashton, 1991; Carmichael and Williams, 1991; Ernst et al., 1994; Lamar, 1997; Conant and Collins, 1998; Powell et al., 1998; Bartlett and Bartlett, 1999; Behler, 1999).

Size: carapace length of 152-626 mm

Native Range: Florida Softshells are indigenous to mainland Florida, southern and eastern Georgia, southern South Carolina, and extreme south-southeastern sections of Alabama (Carr, 1940; Carr and Goin, 1955; Martof, 1956; Webb, 1973, 1989; Mount, 1975; Stevenson, 1976; Behler and King, 1979; Martof et al., 1980; Moler, 1988; Ernst and Barbour, 1989; Ashton and Ashton, 1991; Carmichael and Williams, 1991; Iverson, 1992; Ernst et al., 1994; Conant and Collins, 1998; King, 2000). They do not range throughout the Florida Keys as erroneously depicted by Bartlett and Bartlett (1999).
Hydrologic Unit Codes (HUCs) Explained
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 Apalone ferox are found here.

StateFirst ObservedLast ObservedTotal HUCs with observations†HUCs with observations†
FL199119921Florida Bay-Florida Keys
NY199919991Lower Hudson
NC190019001Upper Neuse
PR200620071Eastern Puerto Rico
SC201420192Edisto River; Salkehatchie

Table last updated 7/23/2024

† Populations may not be currently present.

Means of Introduction: It is not clear how A. ferox were introduced to Big Pine Key, Florida, or if they are actually an indigenous, isolated population (Lazell, 1989).

The A. ferox found in North Carolina probably escaped from captivity (Palmer and Braswell, 1995).

The Florida Softshells in New York Harbor were intentionally released as part of a religious ceremony (Williams, 1999).

Status: The Florida softshells on Big Pine Key, Florida, are probably established but Lazell (1989) is not certain if they truly form a breeding population.

Apolone ferox is not established in North Carolina (Palmer and Braswell, 1995). Any A. ferox in North Carolina probably could not survive the colder winter weather.

The fate of the Florida softshells released into New York Harbor, New York, remains unknown, but it is highly unlikely that this southern species can survive the temperate climate and deep, highly urbanized harbor.

Impact of Introduction: The impact of A. ferox on Big Pine Key, Florida, probably will never be understood, if indeed they are nonindigenous.

The Florida softshell has made no impact in North Carolina.

Apalone ferox will likely have no impact in New York, where all specimens probably perished during their first contact with freezing winter weather.

Remarks: The taxonomy of A. ferox has been reviewed or summarized by Webb (1973, 1989, 1990), Meylan (1987), and Iverson et al. (200). Webb (1990) has called for retaining the genus name Trionyx for all North American trionychids without providing any detailed evidence (Webb's opinion is accepted by Ernst et al., 1994), but most authorities (Conant and Collins, 1998; Iverson et al., 2000) follow Meylan's (1987) groundbreaking revision placing all North American softshells under Apalone. Summaries on the literature and natural history of Florida softshells can be found in Webb (1973), Ernst and Barbour (1989), and Ernst et al. (1994).  Scientific and standard English names follow Crother (2008).

Apalone ferox is a highly aquatic species that, unlike other Apalone species, prefers lakes, ponds, ditches, large springs, and canals, rather than rivers (Ernst et al., 1994; Conant and Collins, 1998). When found in rivers and creeks, they usually prefer the slower, quieter portions (Ernst et al., 1994; Conant and Collins, 1998). Like many softshells, they may spend some time buried in the soft bottom with only the head protruding (Ernst et al., 1994). While submerged under water they may supplement respiration through gas exchange across the linings of the pharynx and cloaca (Ernst et al., 1994). Florida softshells are carnivores that eat mollusks, crayfish, insects, fish, frogs, snakes, other turtles, birds, and carrion (Pope, 1939; Carr, 1952; Ernst and Barbour, 1989; Ernst et al., 1994). Females lay 4-24 eggs, during spring or summer, which they bury in sandy soil exposed to sunlight (Ernst and Barbour, 1989; Ernst et al., 1994).

Like most softshells, A. ferox is difficult and dangerous to handle because of its sharp claws, sharp, powerful jaws and long protrusive neck; they are quick to defend themselves (Carr, 1952; Lazell, 1989; Conant and Collins, 1998). In Florida, A. ferox is commonly exploited for food (Ashton and Ashton, 1991).

References: (click for full references)

Ashton, R. E., Jr., and P. S. Ashton. 1991. Handbook of Reptiles and Amphibians of Florida. Part Two. Lizards, Turtles & Crocodilians. Revised Second Edition. Windward Publishing, Inc., Miami. 191 pp.

Bartlett, R. D., and P. P. Bartlett. 1999. A Field Guide to Florida Reptiles and Amphibians. Gulf Publishing Company, Houston. 280 pp.

Behler, J. L. 1999. National Audubon Society First Field Guide. Reptiles. Scholastic, Inc., New York. 160 pp.

Behler, J. L., and F. W. King. 1979. The Audubon Society Field Guide to North American Reptiles and Amphibians. Alfred A. Knopf, Inc., New York. 743 pp.

Carmichael, P., and W. Williams. 1991. Florida's Fabulous Reptiles and Amphibians. World Publications, Tampa. 120 pp.

Carr, A. F., Jr. 1940. A contribution to the herpetology of Florida. University of Florida Publications, Biological Sciences Series 3(1):1-118.

Carr, A. 1952. Handbook of Turtles. The Turtles of the United States, Canada, and Baja California. Comstock Publishing Associates, Ithaca and London. 542 pp.

Carr, A. [F., Jr.], and C. J. Goin. 1955. Guide to the Reptiles, Amphibians and Fresh-Water Fishes of Florida. University of Florida Press, Gainesville. 341 pp.

Conant, R., and J. T. Collins. 1998. A Field Guide to Reptiles & Amphibians. Eastern and Central North America. Third Edition, Expanded. Houghton Mifflin Company, Boston. 616 pp.

Crother, B.I. (chair). Committee on Standard and English and Scientific Names. 2008. Scientific and standard English names of amphibians and reptiles of North America north of Mexico, with comments regarding confidence in our understanding. Society for the Study of Amphibians and  Reptiles Herpetological Circular. No. 37. iii + 86p.

Ernst, C. H., and R. W. Barbour. 1972. Turtles of the United States and Canada. The University Press of Kentucky, Lexington. 347 pp.

Ernst, C. H., and R. W. Barbour. 1989. Turtles of the World. Smithsonian Institution Press, Washington, D.C. and London. 313 pp.

Ernst, C. H., J. E. Lovich, and R. W. Barbour. 1994. Turtles of the United States and Canada. Smithsonian Institution Press, Washington and London. 578 pp.

Iverson, J. B. 1992. A Revised Checklist with Distribution Maps of the Turtles of the World. John B. Iverson, Richmond, Indiana. 363 pp.

Iverson, J. [B.], P. [A.] Meylan, and M. [E.] Seidel. 2000. Testudines—turtles. Pp. 75-82. In: B. I. Crother (chair), and Committee on Standard English and Scientific Names (editors). Scientific and standard English names of amphibians and reptiles of North America north of Mexico, with comments regarding confidence in our understanding. Society for the Study of Amphibians and Reptiles Herpetological Circular (29):i-iii, 1-82.

King, F. W. 2000. Florida Museum of Natural History's Checklist of Florida Amphibians and Reptiles [online]. Florida Museum of Natural History, University of Florida, Gainesville. Available on URL: http://www.flmnh.ufl.edu/herps/FL-GUIDE/Flaherps.htm.

Lamar, W. W. 1997. The World's Most Spectacular Reptiles & Amphibians. World Publications, Tampa. 210 pp.

Lazell, J. D., Jr. 1989. Wildlife of the Florida Keys: A Natural History. Island Press, Washington, D.C. 250 pp.

Martof, B. S. 1956. Amphibians and Reptiles of Georgia. University of Georgia Press, Athens, Georgia. 94 pp.

Martof, B. S., W. M. Palmer, J. R. Bailey, and J. R. Harrison III. 1980. Amphibians and Reptiles of the Carolinas and Virginia. The University of North Carolina Press, Chapel Hill. 264 pp.

Meylan, P. A. 1987. The phylogenetic relationships of soft-shelled turtles (Family Trionychidae). Bulletin of the American Museum of Natural History 186(1):1-101.

Moler, P. 1988. A Checklist of Florida's Amphibians and Reptiles. Nongame Wildlife Program, Florida Game and Fresh Water Fish Commission, Tallahassee. 18 pp.

Mount, R. H. 1975. The Reptiles and Amphibians of Alabama. Auburn University Agricultural Experiment Station, Auburn. 347 pp.

Obst, F. J. 1986. Turtles, Tortoises and Terrapins. St Martin's Press, New York. 231 pp.

Palmer, W. M., and A. L. Braswell.1995. Reptiles of North Carolina. The University of North Carolina Press for North Carolina State Museum of Natural Sciences, Chapel Hill and London. 412 pp.

Pope, C. H. 1939. Turtles of the United States & Canada. Alfred A. Knopf, New York. 343 + v pp. (Reprinted 1971.)

Powell, R., J. T. Collins, and E. D. Hooper, Jr. 1998. A Key to Amphibians & Reptiles of the Continental United States and Canada. University Press of Kansas, Lawrence. 131 pp.

Pritchard, P. C. H. 1979. Encyclopedia of Turtles. T.F.H. Publications, Inc., Neptune, New Jersey. 895 pp.

Smith, H. M., and E. D. Brodie, Jr. 1982. A Guide to Field Identification. Reptiles of North America. Golden Press, New York. 240 pp.

Stevenson, H. S. 1976. Vertebrates of Florida. Identification and Distribution. University Presses of Florida, Gainesville. 607 pp.

Webb, R. G. 1973. Trionyx ferox. Catologue of American Amphibians and Reptiles (138):1-3.

Webb, R. [G.]. 1989. Apalone ferox (Schneider 1783). Pp. 106-107. In: F. W. King and R. L. Burke (editors). Crocodilian, Tuatara, and Turtle Species of the World. A Taxonomic and Geographic Reference. The Association of Systematics Collections, Washington, DC. 216 pp.

Webb, R. G. 1990. Trionyx. Catalogue of American Amphibians and Reptiles (487):1-7.

Williams, T. 1999. The terrible turtle trade. Audubon 101(2):44, 46-48, 50-51.

Other Resources:
Photograph by William Flaxington. Obtained with photographer's permission at elib.cs.berkeley.edu

Nonindigenous Species Website Links

Wild herp: Florida softshell


Author: Somma, L.A.

Revision Date: 10/28/2009

Citation Information:
Somma, L.A., 2024, Apalone ferox (Schneider, 1783): U.S. Geological Survey, Nonindigenous Aquatic Species Database, Gainesville, FL, https://nas.er.usgs.gov/queries/factsheet.aspx?SpeciesID=1273, Revision Date: 10/28/2009, Access Date: 7/23/2024

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.


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Citation information: U.S. Geological Survey. [2024]. Nonindigenous Aquatic Species Database. Gainesville, Florida. Accessed [7/23/2024].

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