A Guide to the Amphibians
and Reptiles of California

Spiny Softshell - Apalone spinifera

Texas Spiny Softshell - Apalone spinifera emoryi

(Agassiz, 1857)

Click on a picture for a larger view
Texas Spiny Softshell locations in California
Red: Locations where this non-native species
has been observed and may be established.

Click on the map for a topographical view

Map with California County Names

List of Non-Native Reptiles and Amphibians
Established in California

observation link

This species has been introduced into California. It is not a native species.

Texas Spiny Softshell Texas Spiny Softshell Texas Spiny Softshell
Adult, Imperial County © Gary Nafis. Specimen courtesy of Jeff Lemm & Rick Sturm
Texas Spiny Softshell Texas Spiny Softshell Texas Spiny Softshell
Adult Imperial County
© William Flaxington
Captive adult, specimen courtesy of Tim Burkhardt  © Gary Nafis
Texas Spiny Softshell Texas Spiny Softshell Texas Spiny Softshell
Adult, Kern County © John Reinsch
Texas Spiny Softshell Texas Spiny Softshell Texas Spiny Softshell
Adult, Santa Clara County © Grayson B. Sandy
Texas Spiny Softshell Texas Spiny Softshell Texas Spiny Softshell
Adult, Los Angeles County © Jonathan Hakim
Texas Spiny Softshell Texas Spiny Softshell Texas Spiny Softshell
Adult in pond, Los Angeles County © Jonathan Hakim Adult resting just below the surface of an irrigation canal in Imperial County that kept ducking underwater whenever I tried to photograph it. (This species can be very wary.)
Texas Spiny Softshell    
Adult, Imperial County © Kenny Elliott    
Texas Spiny Softshells From Outside California
Texas Spiny Softshell Texas Spiny Softshell Texas Spiny Softshell
Adult, Clark County, Nevada © Zachary Cava
Texas Spiny Softshell Texas Spiny Softshells  
Adult female,  Brewster County, Texas
© Dick Bartlett
Adult female (left) and male (right)
Brewster County, Texas © Dick Bartlett
Texas Spiny Softshell Habitat Texas Spiny Softshell Habitat Texas Spiny Softshell Habitat
Habitat, Colorado River, Imperial County Habitat, Imperial County lake Habitat, Colorado River, Imperial County
Texas Spiny Softshell Habitat
Texas Spiny Softshell Habitat Texas Spiny Softshell Habitat
Habitat, San Pablo Reservoir,
Contra Costa County
Habitat, agricultural drain,
Imperial County
Habitat, agricultural irrigation ditch,
Imperial County
Texas Spiny Softshell Habitat Texas Spiny Softshell Habitat Texas Spiny Softshell Habitat
Artificial pond habitat, Los Angeles County © Jonathan Hakim Habitat, Orange County
© Jonathan Hakim
Urban water channel habitat, Orange County © John Gilkerson
  Texas Spiny Softshell Habitat  
  Habitat, agricultural irrigation ditch, Imperial County  
5 - 21 inches in shell length (12.7 - 53.3 cm). (Stebbins 2003)

A very flat turtle with a rounded, leathery-skinned, flexible, shell which is keelless and unhinged.
The snout is long with open nostrils on the end.
The limbs are flat with broadly-webbed feet.
Color and Pattern
Color is olive, brown or grayish, sometimes with dark markings which fade with age.
The head and limbs are olive to gray with dark markings.
Two dark-bordered light stripes mark each side of the head, extending from the back of the eye and from the back of the angle of the jaw.
The shell has a yellowish border with a dark line around it.
The carapace is rimmed with pale coloring which is four to five times wider on the rear than on the front and sides.
There are pale conical spiny projections (tubercles) along the rear third of the shell.
The plastron is yellowish and unmarked.
Male / Female Differences
Males are smaller than females with a thick tail that extends beyond the carapace, and their pattern is more contrasted than that of females.
The shell has a sandpaper-like texture.

Females become more blotched and mottled as they get older and have a smoother shell with well-developed warts on the front edge.
Juveniles have prominent dark markings on the head and the limbs and black spots on the shell.

Life History and Behavior

Thoroughly aquatic, but basks out of the water.
Active most of the year, becoming dormant in cold temperatures.

Often remains hidden underwater with the snout extended up to the surface to breathe.
Turtles Walking on Land Do Not Always Need to be Picked Up and Rescued
Turtles sometimes leave the water to search for food, a better place to live, a mate, or to lay their eggs in the spring - typically from March to June. If you see a turtle walking on the land, it is probably not sick or lost, so the best thing you can do for the turtle is to leave it alone. Some people want to help a turtle they think is in danger by picking it up and bringing it home or to a wildlife rehabilitation center, but most of the time this harms the turtle by removing it from the wild without reason. Sometimes turtles do get lost or stranded in yards or on busy roads or somewhere where they may be in danger. If you find one in such a situation, it's ok to move it out of danger, but it's best to leave it in a safe place as close to where you found it as possible.
Difficult to approach, moves very fast on land and in the water.
Capable of scratching vigorously and producing a painful bite if handled.
Diet and Feeding
Predominately carniverous. Eat insects, crayfish, worms, snails, fish, frogs, tadpoles, and reptiles.
Both actively hunts its prey and sits still to ambush passing prey. May also scavenge its food.
From May to August, females crawl onto land to lay 1 or 2 clutches of 3 - 39 eggs on exposed, sunny, sandy banks. Hatchlings emerge from August to October.

In California, it is found in permanent, not temporary, rivers, agricultural canals, drainage ditches, artificial lakes and ponds. Prefers still water with a muddy, sandy, or gravelly bottom, and aquatic vegetation.

Geographical Range
The species Apalone spinifera - Spiny Softshell, ranges widely through most of the central  and southeastern part of the United States with isolated populations in Montana and extreme southern Canada north of New York, and ranging south into northeastern Mexico.

The subspecies Apalone spinifera emoryi, Texas Spiny Softshell, is native to the Rio Grande and Pecos River drainages in Texas and New Mexico, and the lower Rio Grande Valley in Texas, and northern Mexico. It has also been introduced into parts of Arizona, New Mexico, Nevada, Utah, and Baja California.

Range in California

First introduced into the lower Colorado river, Apalone spinifera emoryi has extended its range west into the Imperial Valley and north to the Salton Sea in Imperial and Riverside Counties and continues to spread farther north in the Coachella Valley.

"Spiny Softshells were introduced to the Colorado and Gila rivers in Arizona around 1900 (Miller 1946, Bury and Luckenbach 1976). From the Colorado River, they presumably moved through irrigation canals and/or the New and Alamo Rivers from Mexico to Imperial County. Museum records show that this species had colonized the Imperial Valley by the 1940s and 1950s." 
(David M. Goodward and Mihael D. Wilcox. The Rio Grande leopard frog (Lithobates berlandieri) and other introduced and native riparian herpetofauna of the Coachella Valley, Riverside County, California. California Fish and Game 105(2):48-71; 2019)

Apalone spinifera have also been observed in scattered locations in the central valley and around the SF Bay Area, where they are probably released pets and may not be established. Because of the similarty of Texas Spiny Softshells to other kinds of softshell turtles that are kept as pets and may be abandoned in the state, it's hard to know exactly what kind of softshell turtle is found at any location. My range maps should be considered incomplete, and it's likely that not all of the locations shown represent established populations.
Full Species Range Map
Notes on Taxonomy

Six subspecies are recognized including one endemic in Mexico.
The former subspecies A. s. hartwegi - Western Spiny Softshell, was synonymized with A. s. spinifera in 2008 by McGaugh et al. (2008, Zoologica Scripta 37:289-304)

Formerly classified in the genus Trionyx (Trionyx spinifera emoryi)

Alternate and Previous Names (Synonyms)

Apalone spinifera - Spiny Softshell Turtle (Stebbins & McGinnis 2012)
Trionyx spiniferus emoryi - Texas Spiny Softshell (Stebbins 1985, 2003)
Trionyx spiniferus emoryi - Texas Softshell (Stebbins 1966)
Trionyx ferox emoryi - Spiny Soft-shelled Turtle (Stebbins 1954)

Conservation Issues  (Conservation Status)
Family Trionychidae Softshell Turtles Bell, 1828
Genus Apalone North American Softshells Rafinesque, 1832
Species spinifera Spiny Softshell (LeSueur, 1827)

emoryi Texas Spiny Softshell (Agassiz, 1857)
Original Description
Apalone spinifera - (Le Sueur, 1827) - Mem. Mus. Hist. Nat. Paris, Vol. 15, p. 258, pl. 6
Apalone spinifera emoryi - (Agassiz, 1857) - Contr. Nat. Hist. U. S., Vol. 1, p. 407; Vol. 2, pl. 6, figs. 4 and 5

from Original Description Citations for the Reptiles and Amphibians of North America © Ellin Beltz

Meaning of the Scientific Name
Apalone - Greek - apalos - soft, tender - referring to the soft shell
- Latin - spina- thorn or spine, and -ifer - bearing - refers to the spine-like tubercules along front edge of upper shell
emoryi - honors Emory, William H.

from Scientific and Common Names of the Reptiles and Amphibians of North America - Explained © Ellin Beltz

Alternate Names
formerly Trionyx spiiferus emoryi

Related or Similar California Turtles
No other turtles, native or introduced, are similar in appearance to the Texas Spiny Softshell. However, sometimes other species of softshell turtles sold as pets or found in Asian food markets are released into the wild.

More Information and References
California Department of Fish and Wildlife

Resources List


Stebbins, Robert C., and McGinnis, Samuel M.  Field Guide to Amphibians and Reptiles of California: Revised Edition (California Natural History Guides) University of California Press, 2012.

Stebbins, Robert C. California Amphibians and Reptiles. The University of California Press, 1972.

Flaxington, William C. Amphibians and Reptiles of California: Field Observations, Distribution, and Natural History. Fieldnotes Press, Anaheim, California, 2021.

Samuel M. McGinnis and Robert C. Stebbins. Peterson Field Guide to Western Reptiles & Amphibians. 4th Edition. Houghton Mifflin Harcourt Publishing Company, 2018.

Stebbins, Robert C. A Field Guide to Western Reptiles and Amphibians. 3rd Edition. Houghton Mifflin Company, 2003.

Behler, John L., and F. Wayne King. The Audubon Society Field Guide to North American Reptiles and Amphibians. Alfred A. Knopf, 1992.

Powell, Robert., Joseph T. Collins, and Errol D. Hooper Jr. A Key to Amphibians and Reptiles of the Continental United States and Canada. The University Press of Kansas, 1998.

Bartlett, R. D. & Patricia P. Bartlett. Guide and Reference to the Turtles and Lizards of Western North America (North of Mexico) and Hawaii. University Press of Florida, 2009.

Carr, Archie. Handbook of Turtles: The Turtles of the United States, Canada, and Baja California. Cornell University Press, 1969.

Ernst, Carl H., Roger W. Barbour, & Jeffrey E. Lovich. Turtles of the United States and Canada. Smithsonian Institution 1994. (2nd Edition published 2009)
Lemm, Jeffrey. Field Guide to Amphibians and Reptiles of the San Diego Region (California Natural History Guides). University of California Press, 2006.

Conservation Status

The following conservation status listings for this animal are taken from the April 2024 State of California Special Animals List and the April 2024 Federally Listed Endangered and Threatened Animals of California list (unless indicated otherwise below.) Both lists are produced by multiple agencies every year, and sometimes more than once per year, so the conservation status listing information found below might not be from the most recent lists. To make sure you are seeing the most recent listings, go to this California Department of Fish and Wildlife web page where you can search for and download both lists:

A detailed explanation of the meaning of the status listing symbols can be found at the beginning of the two lists. For quick reference, I have included them on my Special Status Information page.

If no status is listed here, the animal is not included on either list. This most likely indicates that there are no serious conservation concerns for the animal. To find out more about an animal's status you can also go to the NatureServe and IUCN websites to check their rankings.

Check the current California Department of Fish and Wildlife sport fishing regulations to find out if this animal can be legally pursued and handled or collected with possession of a current fishing license. You can also look at the summary of the sport fishing regulations as they apply only to reptiles and amphibians that has been made for this website.

This turtle is not included on the Special Animals List, which indicates that there are no significant conservation concerns for it in California.

Organization Status Listing  Notes
NatureServe Global Ranking
NatureServe State Ranking
U.S. Endangered Species Act (ESA)
California Endangered Species Act (CESA)
California Department of Fish and Wildlife
Bureau of Land Management
USDA Forest Service


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