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.

Kinosternon scorpioides
Kinosternon scorpioides
(Scorpion Mud Turtle)

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Kinosternon scorpioides (Linnaeus, 1766)

Common name: Scorpion Mud Turtle

Synonyms and Other Names: chachagua, tortuga de pecho quebrado, pecho quebrado

Taxonomy: available through www.itis.govITIS logo

Identification: Kinosternon scorpioides is a medium to large kinosternid (mud turtle) with a variably domed, oval carapace (upper shell) having a length of 92-270 mm (3.6-10.6 in) (Pritchard and Trebbau, 1984; Ernst and Barbour, 1989; Berry and Iverson, 2001). The carapace can have three keels (ridges) in many individuals (Savage and Villa, 1986; Ernst and Barbour, 1989). The plastron (lower shell) has two hinges and little or no anal notch on the posterior lobe (Ernst and Barbour, 1989; Berry and Iverson, 2001). The first vertebral scute (shield or lamina) of the carapace is wider than it is long, and vertebral scutes 1-4 have distinct posterior notches (Berry and Iverson, 2001). The color of the carapace varies from light brown, to olive, or black; the head can be brown, gray, or black with a reticulated or spotted pattern of cream, orange, red, pink, or yellow (Pritchard and Trebbau, 1984; Berry and Iverson, 2001). In most individuals the tip of the tail has a horny spine (Berry and Iverson, 2001). This description of K. scorpioides should be compared with the anatomical features of other similar-looking North American kinosterids described in other works (Ernst and Barbour, 1989; Ernst et al., 1994; Conant and Collins, 1998). The individual subspecies (geographic races) are defined and described by Berry and Iverson (2001); they are: Kinosternon scorpioides abaxillare Bauer in Stejneger, 1925, Kinosternon scorpioides albogulare (Duméril and Bocourt, 1870), Kinosternon scorpioides cruentatum (Duméril and Bibron in Duméril and Duméril, 1851), and Kinosternon scorpioides scorpioides (Linnaeus, 1766). The scorpion mud turtle is illustrated by a variety of authors (Pritchard, 1979; Smith and Smith, 1979; Freiberg, 1981; Pritchard and Trebbau, 1984; Ernst and Barbour, 1989; Alvarez del Toro, 1982; Murphy, 1997; Campbell, 1998; Berry and Iverson, 2001).

Size: carapace length of 92-270 mm

Native Range: Kinosternon scorpioides is indigenous to south-southeastern Mexico including Isla Cozumel), southward to Belize, and Caribbean drainages in Honduras, Nicaragua, and on Isla de San Andres, Colombia. Additionally, it is distributed in Pacific drainages in southern Mexico, Central America to Panama; Atlantic drainages, and other inland or coastal regions of South America including Bolivia, Brazil, Colombia, the Guianas, Ecuador, Peru, Trinidad, Venezuela, and disjunct populations in Argentina and Paraguay (Smith and Smith, 1973, 1976, 1979, 1993; Alvarez del Toro, 1982; Pritchard and Trebbau, 1984; Savage and Villa, 1986; Ernst and Barbour, 1989; Iverson, 1989, 1992; Schwartz and Henderson, 1991; Flores-Villela, 1993; Murphy, 1997; Campbell, 1998; Crother, 1999; Berry and Iverson, 2001). The most detailed descriptions of the indigenous ranges of the four subspecies of K. scorpioides are provided by Berry and Iverson (2001).

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 Kinosternon scorpioides are found here.

StateFirst ObservedLast ObservedTotal HUCs with observations†HUCs with observations†
FL196419641Florida Southeast Coast

Table last updated 5/24/2022

† Populations may not be currently present.

Means of Introduction: The scorpion mud turtles in Dade County, Florida, were intentionally released by an animal importer (King and Krakauer, 1966).

Status: These turtles are not established in Florida because they have not been seen since their release (King and Krakauer, 1966).

Impact of Introduction: Since this highly adaptable turtle has ecological similarities to indigenous kinosternids and is a successful generalist, K. scorpioides has a great potential to impact indigenous ecosystems if it ever becomes established.

Remarks: The taxonomy of K. scorpioides has been reviewed or summarized by Smith and Smith (1979), Iverson (1989, 1991, 1998), and Berry and Iverson (2001). Additionally, a wide array of regional vernacular names have been applied to this turtle and compiled by several authors (Mittermeier et al., 1980; Liner, 1994). The reference to "scorpion" in this turtle's name is apparently based upon the spine on the tip of the tail (Berry and Iverson, 2001). The literature and natural history of K. scorpioides has been summarized a variety of authors (Smith and Smith, 1973, 1976, 1979, 1993; Pritchard and Trebbau, 1984; Ernst and Barbour, 1989; Iverson, 1992; Berry and Iverson, 2001).


The scorpion mud turtle is a highly aquatic, adaptable kinosternid that inhabits almost any body of water (Pritchard and Trebbau, 1984; Ernst and Barbour, 1989; Alvarez del Toro, 1982; Berry and Iverson, 2001). This turtle is primarily omnicarnivorous, voraciously feeding on a wide variety of aquatic invertebrates and vertebrates, including carrion (Pritchard and Trebbau, 1984; Ernst and Barbour, 1989). In captivity, poorly fed K. scorpioides can be cannibalistic, biting off the toes and limbs of conspecifics (Pritchard and Trebbau, 1984). Females probably lay 1-6 hard-shelled eggs (Pritchard and Trebbau, 1984; Ernst and Barbour, 1989). Like many kinosternids they probably construct a shallow terrestrial nest with little cover (Pritchard and Trebbau, 1984).

References: (click for full references)

Alvarez del Toro, M. 1982. Los Reptiles de Chiapas. Tercera Edición, Corregida y Aumentada. Instituto de Historia Natural, Tuxtla Gutierrez, Chiapas, Mexico. 248 pp.

Berry, J. F., and J. B. Iverson. 2001. Kinosternon scorpioides. Catologue of American Amphibians and Reptiles (725):1-11.

Campbell, J. A. 1998. Amphibians and Reptiles of Northern Guatemala, the Yucatán, and Belize. University of Oklahoma Press, Norman, Oklahoma. 380 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. 1999. Evolutionary relationships. Pp. 269-334. In: B. I. Crother (editor). Caribbean Amphibians and Reptiles. Academic Press, San Diego. 495 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.

Flores-Villela, O. 1993. Herpetofauna Mexicana. Carnegie Museum of Natural History Special Publication (17):i-iv, 1-73.

Freiberg, M. 1981. Turtles of South America. T.F.H. Publications, Inc., Neptune, New Jersey. 125 pp.

Iverson, J. [B.] 1989. Kinosternon scorpioides (Linnaeus 1766). P. 65. 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.

Iverson, J. B. 1991. Phylogenetic hypotheses for the evolution of modern kinosternine turtles. Herpetological Monographs 5:1-27.

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. 1998. Molecules, morphology, and mud turtle phylogenetics (Family Kinosternidae). Chelonian Conservation and Biology 3(1):113-117.

King, [F.] W., and T. Krakauer. 1966. The exotic herpetofauna of southeast Florida. Quarterly Journal of the Florida Academy of Sciences 29(2):144-154.

Liner, E. A. 1994. Scientific and common names for the amphibians and reptiles of Mexico in English and Spanish. Nombres científicos y comunes en Ingles y Españole de los anfibios y los reptiles de México. Society for the Study of Amphibians and Reptiles Herpetological Circular (23):i-vi, 1-113.

Mittermeier, R. A., F. Medem, and A. G. J. Rhodin. 1980. Vernacular names of South American turtles. Society for the Study of Amphibians and Reptiles Herpetological Circular (9):1-44.

Murphy, J. C. 1997. Amphibians and Reptiles of Trinidad and Tobago. Krieger Publishing Company, Malabar, Florida. 245 pp. + 172 plates.

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

Pritchard, P. C. H., and P. Trebbau. 1984. The Turtles of Venezuela. Contributions to Herpetology 2. Society for the Study of Amphibians and Reptiles, Ithaca. 403 pp., 47 plates, 16 maps.

Savage, J. M., and J. Villa R. 1986. Introduction to the herpetofauna of Costa Rica. Introducción a la herptofauna de Costa Rica. Society for the Study of Amphibians and Reptiles Contributions to Herpetology (3):i-viii, 1-207.

Schwartz, A., and R. W. Henderson. 1991. Amphibians and Reptiles of the West Indies: Descriptions, Distributions, and Natural History. University of Florida Press, Gainesville. 720 pp.

Smith, H. M., and A. J. Kohler. 1978. A survey of herpetological introductions in the United States and Canada. Transactions of the Kansas Academy of Science 1977 80(1-2):1-24.

Smith, H. M., and R. B. Smith. 1973. Synopsis of the Herpetofauna of Mexico. Volume II. Analysis of the Literature Exclusive of the Mexican Axolotl. John Johnson Natural History Books, North Bennington, Vermont. 367 pp.

Smith, H. M., and R. B. Smith. 1976. Synopsis of the Herpetofauna of Mexico. Volume III. Source Analysis and Index for Mexican Reptiles. John Johnson, North Bennington, Vermont. 23 pp., Am-T, App-102, Cor-4.

Smith, H. M., and R. B. Smith. 1979. Synopsis of the Herpetofauna of Mexico. Volume VI. Guide to Mexican Turtles. Bibliographic Addendum III. 1044 pp.

Smith, H. M., and R. B. Smith. 1993. Synopsis of the Herpetofauna of Mexico. Volume VII. Bibliographic Addendum IV and Index, Bibliographic Addenda II-IV, 1979-1991. University Press of Colorado, Niwot, Colorado. 1082 pp.

Other Resources:
The Empire of the Turtle

Author: Somma, L.A.

Revision Date: 8/2/2002

Citation Information:
Somma, L.A., 2022, Kinosternon scorpioides (Linnaeus, 1766): U.S. Geological Survey, Nonindigenous Aquatic Species Database, Gainesville, FL, https://nas.er.usgs.gov/queries/FactSheet.aspx?SpeciesID=1266, Revision Date: 8/2/2002, Access Date: 5/24/2022

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. [2022]. Nonindigenous Aquatic Species Database. Gainesville, Florida. Accessed [5/24/2022].

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