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 spinifera emoryi
Apalone spinifera emoryi
(Texas Spiny Softshell)
Native Transplant
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Apalone spinifera emoryi (Agassiz, 1857)

Common name: Texas Spiny Softshell

Taxonomy: available through www.itis.govITIS logo

Identification: Like most trionychids (softshells), Apalone spinifera lacks a hard shell and has a greatly flattened body (Behler and King, 1979; Conant and Collins, 1998; Powell et al., 1998).  Unlike Apalone ferox, the Florida Softshell, A. spinifera has a circular, rather than oblong, carapace (upper shell); the carapace length is 180-540 mm (7-21.25 in) (Ernst et al., 1994; Conant and Collins, 1998).  Unlike other North American Apalone, most males have tiny projections covering part of the carapace giving it a sandpaper-like feel with a row of spines along the anterior edge of the carapace, and usually retain a juvenile pattern of dark (or white in western subspecies) spots (large and circular or tiny blotches) (Conant and Collins, 1998).  Adult females have a smooth, typically patternless carapace, usually (lacking in some) adorned with a row of spines or single row of tubercles of variable size along its anterior edge (Stebbins, 1985; Conant and Collins, 1998).  This combination of features of the carapace separates Spiny Softshells from A. ferox and Apalone mutica (Smooth Softshell).  Like A. ferox, but unlike A. mutica, spiny sofshells have horizontal ridges projecting from the nasal septum (Collins, 1993; Ernst et al., 1994; Conant and Collins, 1998; Powell et al., 1998).  The pale background color of juvenile A. spinifera does not compare to the darker, more colorful patterning of juvenile A. ferox (Conant and Collins, 1998).  See the species account titled "Apalone ferox (Schneider, 1783)" on this website. 

There are currently six recognized subspecies (geographic races) of Spiny Softshells (Webb, 1973; Conant and Collins, 1998; Iverson et al., 2000):  Apalone spinifera aspera (Agassiz, 1857), Gulf Coast Spiny Softshell; A. s. emoryi (Agassiz, 1857), Texas Spiny Softshell; A. s. guadalupensis (Webb, 1962), Guadalupe Spiny Softshell; A. s. hartwegi (Conant and Goin, 1948), Western Spiny Softshell; A. s. pallida (Webb, 1962), Pallid Spiny Softshell; A. s. spinifera (Lesueur, 1827), Eastern Spiny Softshell.  Ernst et al. (1994), and Conant and Collins (1989) should be consulted for morphological differences between the six subspecies.  Spiny Softshells have been widely illustrated by numerous authors (Carr, 1952; Smith, 1961; Ernst and Barbour, 1972, 1989; Stebbins, 1972, 1985; Mount, 1975; Behler and King, 1979; Pritchard, 1979; Martof et al., 1980; Caldwell and Collins, 1981; Vogt, 1981; Smith and Brodie, 1982; Cook, 1984; Obst, 1986, 1998; Garrett and Barker, 1987; Green and Pauley, 1987; Dundee and Rossman, 1989; Harding and Holman, 1990; Carmichael and Williams, 1991; Collins, 1993; Ernst et al., 1994; Oldfield and Moriarty, 1994; Palmer and Braswell, 1995; Degenhardt et al., 1996; Conant and Collins, 1998; Powell et al., 1998; Behler, 1999; Hammerson, 1999; Phillips et al., 1999; Johnson, 2000; Hulse et al., 2001; Minton, 2001; Zug et al., 2001).

Size: 180-540 mm carapace length

Native Range: Apalone spinifera is a wide-ranging species occurring almost continuously throughout the Central Plains states from northern Mexico to as far north as South Dakota; throughout the Midwest states ranging north to Minnesota, Wisconsin, Michigan, and Ontario, Canada; east to western West Virginia, Pennsylvania and New York, with disjunct populations Quebec, Canada, and in eastern New York and Vermont; throughout the Coastal Plains and Gulf Coast states starting from southern North Carolina ranging southward and westward to the western Panhandle of Florida and extreme northeastern Florida (Bishop, 1923; Martof, 1956; Smith, 1961; Webb, 1970; Mount, 1975; Vogt, 1981; DeGraaf and Rudis, 1983; Cook, 1984; Lynch, 1985; Garrett and Barker, 1987; Green and Pauley, 1987; Moler, 1988; [Sievert] and Sievert, [1988]; Carpenter and Krupa, 1989; Dundee and Rossman, 1989; Harding and Holman, 1990; Ashton and Ashton, 1991; Carmichael and Williams, 1991; Gibbons and Semlitsch, 1991; Collins, 1993; Mitchell, 1994; Oldfield and Moriarty, 1994; Palmer and Braswell, 1995; Casper, 1996; Conant and Collins, 1998; Bartlett and Bartlett, 1999a, b; Phillips et al., 1999; Ballinger et al., 2000; Dixon, 2000; Johnson, 2000; King, 2000; Hulse et al., 2001; Minton, 2001).  The western border of the range of Spiny Softshells extends into river systems from Wyoming, Colorado and New Mexico, including disjunct areas in eastern Wyoming and the Missouri River drainage of Montana (Webb, 1973; Stebbins, 1985; Iverson, 1992; Ernst et al., 1994; Hammerson, 1999; Conant and Collins, 1998).

Apalone s. emoryi is confined to the Rio Grande and Pecos River drainages of Texas and New Mexico, south to the Río Purificación, Tamaulipas, Mexico, with an isolated colony in east-central Arizona (Smith and Smith, 1973, 1976, 1979, 1993; Webb, 1973; Stebbins, 1985; Iverson, 1992; Flores-Villela, 1993; Ernst et al., 1994; Stuart, 1995, 2000; Degenhardt et al., 1996; Conant and Collins, 1998).

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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 spinifera emoryi are found here.

StateYear of earliest observationYear of last observationTotal HUCs with observations†HUCs with observations†
Arizona1904199811Havasu-Mohave Lakes; Imperial Reservoir; Lake Mead; Lower Colorado; Lower Gila; Lower Gila-Painted Rock Reservoir; Lower Salt; Middle Gila; Upper Gila; Upper Gila-Mangas; Upper Gila-San Carlos Reservoir
California1945201810Coyote; Imperial Reservoir; Lower San Joaquin River; Sacramento Headwaters; Salton Sea; Salton Sea; San Diego; San Gabriel; San Pablo Bay; Yuma Desert
Nevada196719985Havasu-Mohave Lakes; Lake Mead; Lower Virgin; Meadow Valley Wash; Muddy
New Mexico199119982Upper Gila; Upper Gila-Mangas
Utah199119911Lower Virgin

Table last updated 10/4/2018

† Populations may not be currently present.

Means of Introduction: The means of introduction of A. s. spinifera in Massachusetts and Virginia are unknown but pet releases or escapes are likely.

The A. s. spinifera in Camden County, New Jersey, may have been intentionally introduced to stock aquaria (Conant, 1961).  Those found in the Maurice River system of New Jersey were intentionally introduced from Indiana in order to establish a breeding population (Conant, 1961).

Apalone s. emoryi in the Gila-Colorado river system may have escaped from an aquaculture pond on a ranch in New Mexico, around 1900, during a flood (Miller, 1946).  Their spread throughout this river system, since their original escape, into the states of Arizona, Utah, Nevada, and California, has been through natural dispersal (Bury and Luckenbach, 1976; Stebbins, 1972, 1985).  Other A. s. emoryi collected or seen in other parts of California are of unknown origin, but probably anthropogenic.

Status: Eastern Spiny Softshells were collected and are not established in Massachusetts (Cardoza et al., 1993) or Virginia (Ernst et al., 1997).

In New Jersey, A. s. spinifera is currently well-established throughout the Maurice River system but probably not Camden County (Conant, 1961;Webb, 1973; Smith and Kohler, 1978; Ernst et al., 1994; Conant and Collins, 1998).  Their slow dispersal through this river system does not seem to indicate that they are highly invasive in New Jersey.

Apalone s. emoryi is currently well-established and invasive throughout the Gila-Colorado River systems in southwestern New Mexico, Arizona (including Alamo Lake on the Bill Williams River), southwestern Utah, eastern Nevada, southern California (including the Salton Sea and San Diego River), and into Mexico to the Gulf of California (Degenhardt and Christiansen, 1974; Smith and Kohler, 1978; Endemic Species Committees, 1982; Stebbins, 1985; Jones, 1988; Degenhardt et al., 1996; Howland, 1996; Conant and Collins, 1998).  In California, A. s. emoryi also is established in the Lower Otay Reservoir, San Diego County (Stebbins, 1985).  The status of individuals collected or observed from the San Pablo Reservoir (Contra Costa County), San Gabriel River and Long Beach (Los Angeles County), Coyote Creek/Guadalupe River system (Santa Clara County), and the Sacramento River system (counties not specified) remains uncertain (Stebbins, 1985; D. Holland, personal communication 1997; J. Quinn, personal communication 2000; J. Abel, personal communication 2001).  Texas Spiny Softshells from Kern County, California (D. Holland, personal communication) may only represent single waifs, not a breeding population.  However, it seems clear that Spiny Softshells are an invasive species in California and may be able to increase its range by dispersing through intersecting artificial canals.

Impact of Introduction: While the impact of the introduction of spiny sofshells throughout various localities in the United States and Mexico remains unknown, established populations in Maurice River system of New Jersey, the Gila-Colorado River system of California, Utah, Arizona, New Mexico, Mexico and Nevada, and the Lower Otay Reservoir and San Diego River of California all occur in localities were there are no native Apalone.  Clearly they could have some impact upon indigenous ecosystems in these regions.

Remarks: The taxonomy of A. spinifera has been reviewed or summarized by Webb (1973, 1989, 1990), Meylan (1987), Iverson et al. (2000), and Weisrock and Janzen (2000).  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; Weisrock and Janzen, 2000) follow Meylan's (1987) groundbreaking revision placing all North American softshells under Apalone.  Summaries on the literature and natural history of Spiny Softshells can be found in Webb (1973), Ernst and Barbour (1989), Ernst et al. (1994), and Hammerson (1999).  Scientific and standard English names follow Crother (2008).

Apalone spinifera is a highly aquatic species that prefers highly-oxygenated rivers, but also inhabits creeks, canals, impoundments, lakes, and oxbows; especially those with a soft bottom, sandbars or mud flats (Stebbins, 1985; Ernst et al., 1994; Conant and Collins, 1998; Hammerson, 1999).  Like many softshells, they may spend some time buried in the soft bottom with only the head protruding (Ernst and Barbour, 1989; 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).  Spiny Softshells are carnivores that eat fish, carrion, crayfish, insects, and a wide variety of other invertebrates (Carr, 1952; Ernst and Barbour, 1989; Ernst et al., 1994).  Females lay 4-39 eggs, during late spring or summer, which they bury in soil exposed to sunlight, often near sand or gravel bars, or further away from water if the proper nest environment is not close (Minton, 1972; Vogt, 1981; Ernst and Barbour, 1989; Ernst et al., 1994; Hammerson, 1999).

Like most softshells, A. spinifera 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; Conant and Collins, 1998), and also are aggressive toward conspecifics (Ernst et al., 1994).  In North America, Apalone species are commonly exploited and exported for the commercial trade in the Asian market (Zug et al., 2001).

References: (click for full references)

Abel, J. 2001. Personal communication—Resident, Palo Alto, California.

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.

Ballinger, R. E, J. W. Meeker, and M. Thies. 2000. A checklist and distribution maps of the amphibians and reptiles of South Dakota. Transactions of the Nebraska Academy of Sciences 26:29-46.

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

Bartlett, R. D., and P. D. Bartlett. 1999b. A Field Guide to Texas Reptiles and Amphibians. Gulf Publishing Company, Houston. 331 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.

Bishop, S. C. 1923. Notes on the herpetology of Albany County, New York, III. Copeia (125):117-120.

Bradley, W. G. and J. E. Deacon. 1967. The biotic communities of southern Nevada. Nevada State Museum Anthropological Papers No. 13, Part 4. 201-273.

Bury, R. B., and R. A. Luckenbach. 1976. Introduced amphibians and reptiles in California. Biological Conservation 1976(10):1-14.

Caldwell, J. P., and J. T. Collins. 1981. Turtles in Kansas. AMS Publishing, Lawrence, Kansas. 67 pp.

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

Cardoza, J. E., G. S. Jones, T. W. French, and D. B. Halliwell. 1993. Exotic and Translocated Vertebrates of Massachusetts. Fauna of Massachusetts Series 6. Massachusetts Division of Fisheries and Wildlife, Westborough, Massachusetts. 106 pp.

Carpenter, C. C., and J. J. Krupa. 1989. Oklahoma Herpetology. An Annotated Bibliography. University of Oklahoma Press, Norman. 258 pp.

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

Casper, G. S. 1996. Geographic Distributions of the Amphibians and Reptiles of Wisconsin. An Interim Report of the Wisconsin Herpetological Atlas Project. Milwaukee Public Museum, Inc., [Milwaukee]. 87 pp.

Collins, J. T. 1993. Amphibians and Reptiles in Kansas. Third Edition, Revised. Museum of Natural History, The University of Kansas, Lawrence. 397 pp.

Conant, R. 1961. The softshell turtle, Trionyx spinifer, introduced and established in New Jersey. Copeia 1961(3):355-356.

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.

Cook, F. R. 1984. Introduction to Canadian Amphibians and Reptiles. National Museums of Canada, Ottawa. 200 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.

Degenhardt, W. G., and J. L. Christiansen. 1974. Distribution and habitats of turtles in New Mexico. The Southwestern Naturalist 19(1):21-46.

Degenhardt, W. G., C. W. Painter, and A. H. Price. 1996. Amphibians and Reptiles of New Mexico. University of New Mexico Press, Albuquerque. 419 pp.

DeGraaf, R. M., and D. D. Rudis. 1983. Amphibians and Reptiles of New England. Habitats and Natural History. The University of Massachusetts Press, Amherst. 85 pp.

Demlong, M. 1997. Personal communication—Herpetologist, Phoenix Zoo, 455 N. Galvin Parkway, Phoenix, Arizona.

Dixon, J. R. 2000. Amphibians and Reptiles of Texas. Second Edition. Texas A & M University Press, College Station. 421 pp.

Dundee, H. A., and D. A. Rossman. 1989. The Amphibians and Reptiles of Louisiana. Louisiana State University Press, Baton Rouge and London. 300 pp + unattached erratum.

Endemic Species Committees. 1982. Endemic Amphibians and Reptiles of the Colorado River System. A Status Report. Colorado Wildlife Council, [Denver]. 43 pp.

Ernst, C. H. 1997. Personal communication—Herpetologist/Professor, Department of Biology, George Mason University, Fairfax, Virginia.

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., S. C. Belfit, S. W. Sekscienski, and A. F. Laemmerzahl. 1997. The amphibians and reptiles of Ft. Belvoir and northern Virginia. Bulletin of the Maryland Herpetological Society 33(1):1-62.

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.

Garrett, J. M., and D. G. Barker. 1987. A Field Guide to Reptiles and Amphibians of Texas. Texas Monthly Press, Austin. 225 pp.

Gibbons, J. W., and R. D. Semlitsch. 1991. Guide to the Reptiles and Amphibians of the Savannah River Site. The University of Georgia Press, Athens, Georgia, and London. 131 pp.

Green, N. B., and T. K. Pauley. 1987. Amphibians and Reptiles in West Virginia. University of Pittsburgh Press, Pittsburgh. 241 pp.

Hammerson, G. A. 1999. Amphibians and Reptiles in Colorado. Second Edition. University Press of Colorado, Niwot, Colorado. 484 pp.

Harding, J. H., and J. A. Holman. 1990. Michigan Turtles and Lizards. Department of Outreach Communications, Michigan State University, East Lansing. 94 pp.

Holland, D. C. 1997. Personal communication—Herpetologist, Fallbrook, California.

Howland, J. M. 1996. Herps of Arizona. The Desert Monitor (Phoenix) 27(1):12-17.

Hulse, A. C., C. J. McCoy, and E. Censky. 2001. Amphibians and Reptiles of Pennsylvania and the Northeast. Comstock Publishing Associates, Ithaca. 419 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.

Johnson, T. R. 2000. The Amphibians and Reptiles of Missouri. Revised and Expanded Second Edition. Missouri Department of Conservation, Conservation Commission of the State of Missouri, Jefferson City. 400 pp.

Jones, B. K. 1988. Distribution and habitat associations of herpetofauna in Arizona: Comparisons by habitat type. Pp. 109-128. In: R. C. Szaro, K. E. Severson, and D. R. Patton (coordinators). Management of Amphibians, Reptiles, and Small Mammals in North America. Proceedings of the Symposium. July 19-21, 1988, Flagstaff, Arizona. United States Department of Agriculture Forest Service, General Technical Report RM-166, Fort Collins. 458 pp.

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.

Lohoefener, R., and R. Altig. 1983. Mississippi herpetology. Mississippi State University Research Center Bulletin (1):i-vi, 1-66.

Lynch, J. D. 1985. Annotated checklist of the amphibians and reptiles of Nebraska. Transactions of the Nebraska Academy of Sciences 23:33-57.

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.

Miller, R. R. 1946. The probable origin of the soft-shelled turtle in the Colorado River Basin. Copeia 1946(1):46.

Minton, S. A., Jr. 2001. Amphibians & Reptiles of Indiana. Revised Second Edition. Indiana Academy of Science, Indianapolis. 404 pp.

Mitchell, J. C. 1994. The Reptiles of Virginia. Smithsonian Institution Press, Washington and London. 352 pp.

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.

Obst, F. J. 1998. Turtles & tortoises. Pp. 108-125. In: H. G. Cogger and R. G. Zweifel (editors). Encyclopedia of Amphibians & Reptiles. Second Edition. Academic Press, San Diego. 240 pp.

Oldfield, B., and J. J. Moriarty. 1994. Amphibians & Reptiles Native to Minnesota. University of Minnesota Press, Minneapolis. 240 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.

Phillips, C. A., R. A. Brandon, and E. O. Moll. 1999. Field Guide to Amphibians and Reptiles of Illinois. Illinois Natural History Survey, Champaign, Illinois. 282 pp.

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.

Quinn, J. F. 2000. Personal communication—Professor, Department of Environmental Science and Policy, University of California, Davis, California.

[Sievert], G., and L. Sievert. [1988]. A Field Guide to Reptiles of Oklahoma. Oklahoma Department of Wildlife Conservation, Oklahoma City. 96 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.

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.

Smith, P. A. 1961. The amphibians and reptiles of Illinois. Illinois Natural History Survey Bulletin 28(1):[i-v], 1-298. (Reprinted 1986.)

Stebbins, R. C. 1972. California Amphibians and Reptiles. University of California Press, Berkeley, Los Angeles, and London. 152 pp.

Stebbins, R. C. 1985. A Field Guide to Western Reptiles and Amphibians. Second Edition. Houghton Mifflin Company, Boston. 336 pp.

Stuart, J. N. 1995. Notes on the aquatic turtles of the Rio Grande drainage, New Mexico. Bulletin of the Maryland Herpetological Society 31(3):147-157.

Stuart, J. N. 2000. Additional notes on native and non-native turtles of the Rio Grande Drainage Basin, New Mexico. Bulletin of the Chicago Herpetological Society 35(10):229-235.

Vogt, R. C. 1981. Natural History of Amphibians and Reptiles in Wisconsin. The Milwaukee Public Museum, Milwaukee. 205 pp.

Webb, R. G. 1970. Reptiles of Oklahoma. University of Oklahoma Press, Norman. 370 pp.

Webb, R. G. 1973. Trionyx spiniferus. Catalogue of American Amphibians and Reptiles (140):1-4.

Webb, R. [G.] 1989. Apalone spinifera LeSueur 1827. P. 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.

Weisrock, D. W., and F. J. Janzen. 2000. Comparative molecular phylogeography of North American softshell turtles (Apalone): Implications for regional and wide-scale historical evolutionary forces. Molecular Phylogenetics and Evolution 14(1):152-164.

Zug, G. R., L. J. Vitt, and J. P. Caldwell. 2001. Herpetology. An Introductory Biology of Amphibians and Reptiles. Second Edition. Academic Press, San Diego. 630 pp.

Author: Somma, L.A.

Revision Date: 10/28/2009

Citation Information:
Somma, L.A., 2019, Apalone spinifera emoryi (Agassiz, 1857): U.S. Geological Survey, Nonindigenous Aquatic Species Database, Gainesville, FL, https://nas.er.usgs.gov/queries/FactSheet.aspx?speciesID=1275, Revision Date: 10/28/2009, Access Date: 2/18/2019

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. [2019]. Nonindigenous Aquatic Species Database. Gainesville, Florida. Accessed [2/18/2019].

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