SMOOTH SOFTSHELL
Apalone mutica (LeSueur 1827)
ā-pă-lō'-nē — mŭ-tĭ-kă


Conservation Status:

State: None

Federal: None
NatureServe State: S4 - Apparently Secure
NatureServe National: N5 - Secure
NatureServe Global: G5 - Secure
CITES: Appendix III

An adult female Smooth Softshell from Labette County. Image © MaxEweleen Hornbuckle Good, 2018.
An adult male Smooth Softshell. Image by Suzanne L. Collins, CNAH.
An adult female Smooth Softshell from Kingman County, Kansas. Image © Ken Brunson.

Description:
Softshell turtles are characterized by flat, flexible carapaces, and plastrons that are much smaller than the upper. Smooth Softshells lack fleshy bumps or tubercles along the front edge of the carapace. Limbs are typically uniform brown in color, and a yellow or white line extends through the eye on each side of the head. Males have much longer heads.
Adults normally 115-306 mm (4½-12 inches) in carapace length; largest specimen from Kansas: female (KU 218796) from Osage County with carapace length of 285 mm (11¼ inches) collected by John Powell and Beverly Downing on 9 June 1991; maximum carapace length throughout range: 14 inches (Conant and Collins, 1998).

Distribution:
Smooth softshells are found in rivers, large streams, and, rarely, large lakes with sandy or muddy bottoms. These lakes are usually close to a large river. Sandbars are important for basking and egg laying sites. They seem to prefer larger rivers and live in colonies along certain portions
Historic records indicate that the Smooth Softshell once occurred statewide.
(, Museum Voucher) (, Observation) (, Literature Record)
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  • Occurrence Summary:  
  • 276
    Records 
  • 253
    Museum Vouchers 
  • 23
    Other Observations 
Some county occurrences indicated below may be too imprecise to map above.
County Breakdown: County Name (# occurrences):
Atchison (2); Barber (4); Comanche (1); Cowley (10); Crawford (1); Dickinson (1); Doniphan (2); Douglas (29); Ellis (4); Ellsworth (1); Finney (1); Geary (1); Harvey (2); Johnson (1); Kearney (1); Kingman (4); Leavenworth (166); Lyon (1); Marshall (1); Neosho (1); Osage (1); Pottawatomie (7); Reno (5); Riley (8); Russell (4); Sedgwick (6); Stafford (1); Sumner (6); Trego (1); Unknown (1); Washington (1); Woodson (1);

Natural History:
Smooth Softshells prefer moving water, rarely leaving except to bask or nest. Nesting typically peaks in May to June and females will deposit clutches of 3-25 eggs. Eggs typically hatch in 2 to 2 ½ months. Smooth Softshells are primarily carnivorous. Males may consume more terrestrial prey than females. The two sexes exhibit some differentiation of habitat, with males occurring more often in shallow water along shorelines, while females prefer deeper water.

Occurrence Activity:
White dates indicate there is at least a single recorded occurrence on that date. The darker blue a date is, the greater the relative number of observations for that date.
Observation Type: (of recorded types)
Remarks:
Most Kansas specimens were collected from the Kansas River below the low water dam at Lawrence, in association with the doctoral research of Dr. Michael Plummer (Fitch and Plummer, 1975; Plummer, 1975, 1977, 1977) and most of our information on the natural history of this species are due to his efforts.
The remainder of the known occurrences are widely scattered across the state. Despite numerous attempts to document this turtle during the study, only one specimen was discovered. Possible reasons for this putative decline are unknown.
Cornelius Rogers took this species on a sandbar at the junction of a small creek and Medicine River, a little less than 5 miles southeast of Lake City, Barber County, Kansas, on August 30, 1934. The form was taken on a bank of Salt River just south of Aetna in the same county on April 21, 1934. Also, on May 25, 1934, an example was secured 6 miles east of Turon, Reno County, Kansas, in a shallow sand-bottomed, algae-filled pasture streamlet (Burt, 1935).
Smooth Softshells may be taken year-round. Daily creel limit is eight turtles, single species or in combination (with Spiny Softshells and/or Snapping Turtles). Possession limit is three creel limits. A valid fishing license is required (unless exempt [e.g. < 16 years of age]). Legal equipment: hand, hook and line, setline, hand dip net, seine, turtle trap, or gig.


Bibliography:
1933 Stejneger, Leonhard and Thomas Barbour. A Checklist of North American Amphibians and Reptiles. 3rd Edition. Harvard University Press, Cambridge, Massachusetts. pp.
1933 Taylor, Edward H. Observations on the courtship of turtles. University of Kansas Science Bulletin 21(6):269-271
1935 Burt, Charles E. Further records of the ecology and distribution of amphibians and reptiles in the middle west. American Midland Naturalist 16(3):311-366
1942 Hudson, G. E. The amphibians and reptiles of Nebraska. Nebraska Conservation Bulletin 24():1-146
1947 Smith, Hobart M. Kyphosis and other variations in soft-shelled turtles. University of Kansas Publications Museum of Natural History 1(6):117-124
1950 Smith, Hobart M. Handbook of Amphibians and Reptiles of Kansas. University of Kansas, Museum of Natural History, Miscellaneous Publication (2):336
1956 Clarke, Robert F. Identification of Kansas turtles. Kansas School Naturalist 2(4):1-3
1956 Clarke, Robert F. Turtles in Kansas. Kansas School Naturalist 2(4):1-15
1962 Gish, Charles D. The Herpetofauna of Ellis County, Kansas. Thesis. Fort Hays State University, Hays, Kansas. 34pp.
1974 Collins, Joseph T. Amphibians and Reptiles in Kansas University of Kansas Museum of Natural History Public Education Series (1):283 pp
1974 Dawson, Mary E. New turtle exhibit at Topeka Zoo. Kansas Herpetological Society Newsletter (3):4-5
1974 Karns, Daryl, Ray E. Ashton, Jr., and Thomas Swearingen. Illustrated Guide to Amphibians and Reptiles in Kansas: An Identification Manual. University of Kansas Publications Museum of Natural History Public Education Series(2):viii + 18
1975 Fitch, Henry S. and Michael V. Plummer. A preliminary ecological study of the softshelled turtle Trionyx muticus in the Kansas River. Israel Journal of Zoology 24():28-42
1975 Plummer, Michael V. Population ecology of the softshell turtle, Trionyx muticus Doctoral Thesis, University of Kansas ():173
1975 Plummer, Michael V. and Hampton W. Shirer. Movement patterns in a river population of the soft-shell turtle, Trionyx muticus. Occasional Papers of the Museum of Natural History, The University of Kansas (43):1-26
1975 Rundquist, Eric M. First KHS field trip yields three county records. Kansas Herpetological Society Newsletter (7):1-3
1976 Plummer, Michael V. Some aspects of nesting success in the turtle, Trionyx muticus. Herpetologica 32(4):353-359
1976 Rundquist, Eric M. Field checklist (of) amphibians and reptiles of Kansas. Kansas Herpetological Society, Lawrence. pp.
1977 Plummer, Michael V. Activity, habitat and population structure in the turtle, Trionyx muticus. Copeia 1977(3):431-440
1977 Plummer, Michael V. Notes on the courtship and mating behavior of the softshell turtle, Trionyx muticus (Reptilia, Testudines, Trionychidae). Journal of Herpetology 11(1):90-92
1977 Plummer, Michael V. Reproduction and growth in the turtle, Trionyx muticus. Copeia 1977(3):440-447
1977 Trott, Gene. Chikaskia River wildlife study. Kansas Herpetological Society Newsletter (19):2-3
1978 Curl, Richard L. Final Environmental Statement: Milford Lake Kansas operation and maintenance. US Army Corps of Engineers, Kansas City District. 158pp.
1978 Kern, Anita, Leslie Rice, and Michelle Warner. The turtles of Sumner County, Kansas. Kansas Herpetological Society Newsletter (27):10-11
1978 Warner, M. and R. Wencel. Chikaskia River study held near Caldwell. Kansas Herpetological Society Newsletter (25):15-16
1980 Clarke, Robert F. Herptiles and fishes of the western Arkansas River in Kansas. United States Army Corps of Engineers, Albuquerque, New Mexico. 55pp.
1981 Bovee, E. C. New epizoic suctorea (Protozoa) of the Smooth Softshell Turtle, Trionyx muticus, in northeastern Kansas. Transactions of the Kansas Academy of Science 84():98-104
1982 Collins, Joseph T. Amphibians and Reptiles in Kansas. 2nd edition. University of Kansas Museum of Natural History Public Education Series (8):
1983 Collins, Joseph T. New records of fishes, amphibians, and reptiles in Kansas for 1982 . Technical Publication of the State Biological Survey of Kansas 13():9-21
1984 Collins, Joseph T. New records of fishes, amphibians, and reptiles in Kansas for 1983. Kansas Herpetological Society Newsletter (56):15-26
1986 Collins, Joseph T. New records of amphibians and reptiles in Kansas for 1986. Kansas Herpetological Society Newsletter (66):9-16
1987 Capron, Marty. Selected observations on south-central Kansas turtles Kansas Herpetological Society Newsletter (67):13-15
1990 Collins, Joseph T. Maximum size records for Kansas amphibians and reptiles. Kansas Herpetological Society Newsletter (81):13-17
1990 Collins, Joseph T. Results of second Kansas herp count held during April-May 1990. Kansas Herpetological Society Newsletter (81):10-12
1991 Conant, Roger and Joseph T. Collins. Peterson Field Guide to Reptiles and Amphibians of Eastern and Central North America. 3rd ed. Houghton Mifflin Company, Boston, Massachusetts. pp.
1992 Collins, Joseph T. New records of amphibians and reptiles in Kansas for 1991. Kansas Herpetological Society Newsletter (87):12-17
1992 Edds, David R. Population status and incidence of anatomical abnormalities in semiaquatic turtles of the Walnut and lower Arkansas river basins. Kansas Department of Wildlife and Parks, Pratt. 58pp.
1992 Taggart, Travis W. KHS field trips. Kansas Herpetological Society Newsletter (91):3
1993 Collins, Joseph T. and Suzanne L. Collins. Amphibians and Reptiles in Kansas. Third Edition. University Press of Kansas, Lawrence, Lawrence. 397pp.
1994 Collins, Joseph T. New records of amphibians and reptiles in Kansas for 1993. Kansas Herpetological Society Newsletter (97):15-19
1995 Anderson, Lewis, Mark Shaw, Jeff Blodig, and Tom Walker. Report to the Kansas Department of Wildlife and Parks: Herps encountered during REmap project, summer 1994. Kansas Herpetological Society Newsletter (99):10-17
1996 Rakestraw, J. Spring herp counts: A Kansas tradition. Reptile & Amphibian Magazine (March-April):75-80
1997 Collins, Joseph T. A report on the KHS fall field trip to the Marais des Cygnes wildlife refuges. Kansas Herpetological Society Newsletter (110):2-3
1998 Collins, Joseph T. New records of amphibians and reptiles in Kansas for 1997. Kansas Herpetological Society Newsletter (111):12-14
1998 Conant, Roger and Joseph T. Collins. Peterson Field Guide to Reptiles and Amphibians of Eastern and Central North America. 3rd ed, expanded. Houghton Mifflin Company, Boston, Massachusetts. pp.
1998 Gamble, Jerre Marais des Cygnes National Wildlife Refuge Comprehensive Conservation Plan U.S. Fish and Wildlife Service, Hartford, Kansas. 91pp.
2001 Collins, Joseph T. New records of amphibians and reptiles in Kansas for 2000. Kansas Herpetological Society Newsletter (124):6-8
2002 Ellis, Mark R. Fall 2002 KHS field trip to Washington County. Journal of Kansas Herpetology (2):4-5
2002 Kingsbury, Bruce and Joanna Gibson. Habitat Management Guidelines for Amphibians and Reptiles of the Midwest. Publication of Partners in Amphibian and Reptile Conservation, Address not given. 152pp.
2003 Suleiman, G. Fort Riley herpetofaunal count. Journal of Kansas Herpetology (5):11-12
2003 Taggart, Travis W. Kansas Herpetological Society 2003 spring field trip. Journal of Kansas Herpetology (5):3-4
2006 Taggart, Travis W. Distribution and status of Kansas herpetofauna in need of information. State Wildlife Grant T7. Kansas Department of Wildlife and Parks, Pratt. vii + 106pp.
2008 Taggart, Travis W. KHS 2008 spring field trip. Journal of Kansas Herpetology (25):2-3
2010 Collins, Joseph T., Suzanne L. Collins, and Travis W. Taggart. Amphibians, Reptiles, and Turtles of Kansas Eagle Mountain Publishing., Provo, Utah. 400pp.
2010 Miller, Larry L. 2010 Investigation of the Checkered Garter Snake in Kansas with notes on other Amphibians, Reptiles, and Turtles encountered. Kansas Department of Wildlife and Parks, Pratt, Kansas. 31pp.
2011 Taggart, Travis W. Kansas Herpetological Society 2011 spring field trip to beheld in Chautauqua County. Journal of Kansas Herpetology (37):5-7
2012 Rohweder, Megan R. Spatial conservation prioritization of Kansas for terrestrial vertebrates. Thesis. Fort Hays State University, Hays, Kansas. 151pp.
2013 Bass, Neil The Missouri River Fish and Wildlife Mitigation Project: For the river, for you, and for herps. Collinsorum 2(1/2):10-11
2015 Bass, Neil. Herpetological (Frog and Turtle) Inventories along the Missouri River in Kansas. Collinsorum 4(1):5-9
2015 Seim, Jeffery Population Structure and Habitat Association of Aquatic Testudines in Quivira National Wildlife Refuge. Thesis. Fort Hays State University, Hays, Kansas. 66pp.
2015 Taggart, Travis W. Summer Field Trip In The Harvey County Sandhills. Collinsorum 4(3):3
2017 Taggart, Travis W. and J. Daren Riedle. A Pocket Guide to Kansas Amphibians, Turtles and Lizards. Great Plains Nature Center, Wichita, Kansas. 69pp.
2018 Houck, Mike Herp Count: Fort Riley Military Installation Collinsorum 7(1):17
2020 Riedle, J. Daren. Revisiting Kansas Herpetological Society field trip and Herp Count data: Distributional patterns and trend data of Kansas amphibians and reptiles. Collinsorum 9(1):7-16
Account Last Updated:
7/29/2020 3:16:07 PM