REPTILIA (Reptiles) CHELONIA (Turtles) TRIONYCHIDAE (Softshells)

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 an ovoid, flat, flexible carapace, and a much-reduced plastron. 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. Females grow larger than males.
Smooth softshell turtles have a tubular snout with round nostrils that are usually positioned inferior, and they lack a septal ridge.
Adults normally 115-306 mm (4½-12 inches) in carapace length. The largest specimen from Kansas is a female (KU 218796) from Osage County with a carapace length of 285 mm (11¼ inches) collected by John Powell and Beverly Downing on 9 June 1991. The maximum carapace length throughout the range is 14 inches (Conant and Collins, 1998).

Distribution:
Smooth Softshells are highly aquatic and found in rivers and large streams with sandy or muddy bottoms. 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 occurs statewide.
(,   Museum Voucher) (,   Observation) (,   Literature Record) (,   iNat Record)
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  • Occurrence Summary:  
  • 288
    Records 
  • 264
    Museum Vouchers 
  • 24
    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 (30); Ellis (4); Ellsworth (1); Finney (2); Geary (1); Harvey (2); Johnson (1); Kearney (1); Kingman (4); Leavenworth (166); Lyon (1); Marshall (1); Neosho (1); Osage (1); Pottawatomie (8); Reno (6); Riley (9); Rooks (1); Russell (4); Sedgwick (11); Stafford (1); Sumner (6); Trego (2); Unknown (1); Washington (1); Woodson (1);

Natural History:
Smooth Softshells prefer moving water, rarely leaving except to bask or nest. Nesting typically peaks from 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.
Remarks:
The Smooth Softshell was first reported from Kansas by Cragin (1880). The earliest known specimen (MCZ 4843) was collected at "Manhattan, Kansas" by Francis W. Cragin on 16 September 1880.
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 remaining known occurrences are widely scattered across the state. It is not a turtle that is observed (with confidence) without considerable work.
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. Another was taken on a bank of Salt River just south of Aetna in the same county on April 21, 1934. 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. The daily creel limit is eight turtles, single species or in combination (with Spiny Softshells and/or Snapping Turtles). The 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:
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1880 Cragin, Francis W. A preliminary catalogue of Kansas reptiles and batrachians Transactions of the Kansas Academy of Science 7():112-123
Also listed the Scarlet Snake (Cemophora coccinea) [=Ophibolus doliatus var. coccineus] and Red Salamander (Pseudotriton ruber) [=Spelerpes ruber] from Kansas.
1916 Householder, Victor H. The Lizards and Turtles of Kansas with Notes on Their Distribution and Habitat. Thesis. University of Kansas, Lawrence. 100pp.
1927 Burt, Charles E. An annotated list of the amphibians and reptiles of Riley County, Kansas. Occasional Papers of the Museum of Zoology, University of Michigan (189):12
Accounts on forty species known from the vicinity of Manhattan, Riley County, Kansas. There have been several scientific names changes since publication, which is understandable... however, some usages cannot be explained by subsequent taxonomic reappraisals(e.g.  Gastrophryne carolinensis for Gastrophryne olivacea). The writer lists Eumeces (=Plestiodon) obsoletus and E. guttulatus yet correctly reasoning that the latter is the young of the former. Within the account of Tantilla gracilis (a common form) the writer mentions that T. nigriceps was reported from Riley County by Branson (1904) but that the specimens at Kansas State were absent at the time of publication. The Prairie Rattlesnake (Crotalus viridis) was first reported from Riley County by Branson (1904) and is reported by the writer based on a specimen in the museum at Kansas State University by Professor E. A. Popenoe. The Prairie Rattlesnake is not currently native to Riley County, and closest reliable localities are 150 to the west.
1933 Stejneger, Leonhard and Thomas Barbour. A Checklist of North American Amphibians and Reptiles. 3rd Edition. Harvard University Press, Cambridge, Massachusetts. pp.
Reference to Kansas is the listed range of several species.
1933 Brumwell, Malcolm J. Distributional records of the reptilia and amphibians of Kansas. Privately printed, . 22pp.
County dot maps of the Kansas herpetofauna.
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
The first modern herpetology of Kansas. Includes locality dot maps within individual species accounts. Reports 96 species from Kansas (table and text say 97 on p. 10) and 13 "probable but unverified" species and subspecies.
1951 Brumwell, Malcolm J. An ecological survey of the Fort Leavenworth Military Reservation American Midland Naturalist 45(1):187-231
Published posthumously. Lieutenant Brumwell died December 14, 1941, as a result of injuries incurred during the Japanese attack on Pearl Harbor. This paper is a condensed version of his thesis for the Master's degree.
1956 Smith, Hobart M. Handbook of Amphibians and Reptiles of Kansas. Second edition. University of Kansas Museum of Natural History Miscellaneous Publication (9):1-356
Hobart M. Smith's updated second edition of his first (1950) modern herpetology of Kansas. Includes locality dot maps within individual species accounts. Reports 96 species from Kansas (table says 97 on p. 10; text says 98 on p. 10) and 11 "probable but unverified" species and subspecies. The second edition has updated taxonomy, added Plestiodon laticeps, and removed Eurycea tynerensis.
1956 Clarke, Robert F. Turtles in Kansas. Kansas School Naturalist 2(4):1-15
1956 Clarke, Robert F. Identification of Kansas turtles. Kansas School Naturalist 2(4):1-3
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
Joseph T. Collins first Kansas herpetology. <Need to get species total and principal differences with previous 'version' (= Smith 1956)>
1974 Dawson, Mary E. New turtle exhibit at Topeka Zoo. Kansas Herpetological Society Newsletter (3):4-5
Info on A. mutica in Kansas.
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 Rundquist, Eric M. Amphibians and Reptiles of Kingman County, Kansas. Privately Printed, Lawrence, Kansas. 3pp.
Short accounts for twenty-nine recognized amphibians and reptiles from Kingman County, Kansas. With habitat descriptions and for some species, estimates of population density.
1975 Rundquist, Eric M. First KHS field trip yields three county records. Kansas Herpetological Society Newsletter (7):1-3
Narration of the activities and species found during the KHS field trip to Kingman County, Kansas. From the title of the article, there were three county records were obtained, however, only Plestiodon septentrionalis is indicated as being 'new'.
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 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
1976 Rundquist, Eric M. Field checklist (of) amphibians and reptiles of Kansas. Kansas Herpetological Society, Lawrence. pp.
1976 Plummer, Michael V. Population ecology of the softshell turtle, Trionyx muticus Dissertation. University of Kansas, Lawrence, Kansas. 173pp.
1976 Plummer, Michael V. Some aspects of nesting success in the turtle, Trionyx muticus. Herpetologica 32(4):353-359
1977 Trott, Gene. Chikaskia River wildlife study. Kansas Herpetological Society Newsletter (19):2-3
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. Activity, habitat and population structure in the turtle, Trionyx muticus. Copeia 1977(3):431-440
1977 Plummer, Michael V. Reproduction and growth in the turtle, Trionyx muticus. Copeia 1977(3):440-447
1978 Curl, Richard L. Final Environmental Statement: Milford Lake Kansas operation and maintenance. US Army Corps of Engineers, Kansas City District. 158pp.
Notable mentions: Spotted Salamander, Smooth Green Snake
1978 Warner, M. and R. Wencel. Chikaskia River study held near Caldwell. Kansas Herpetological Society Newsletter (25):15-16
1978 Kern, Anita, Leslie Rice, and Michelle Warner. The turtles of Sumner County, Kansas. Kansas Herpetological Society Newsletter (27):10-11
1980 Clarke, Robert F. Herptiles and fishes of the western Arkansas River in Kansas. United States Army Corps of Engineers, Albuquerque, New Mexico. 55pp.
A summary of known information on the amphibian, reptile, and fish faunas of the Arkansas River above Great Bend. The report details associated field activities for procuring fish, however no new surveys for amphibians and reptiles were undertaken. Information on herps from Finney County was provided by Michael Rush (FHSU) and thus made available before the publication of his thesis (Rush, 1981). The western Arkansas River drainage had experienced little attention by herpetologists before this study, and the species accounts reflect that paucity of data. Additionally, the report omits several older records (e.g. for Anaxyrus debilisThamnophis cyrtopsis, and Lampropeltis calligaster) from the westernmost reaches of the Arkansas River drainage in Kansas.
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):
Joseph T. Collins second Kansas herpetology. <Need to get species total and principal differences with previous 'version' (= Collins 1974)>
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 Brown, Kenneth L. Pomona: A plains village variant in eastern Kansas and western Missouri. Dissertation. University of Kansas, Lawrence, Kansas. 519pp.
1984 Collins, Joseph T. New records of fishes, amphibians, and reptiles in Kansas for 1983. Kansas Herpetological Society Newsletter (56):15-26
Invalidated the specimens of Thamnophis sirtalis from Hamilton County (reidentified as T. cyrtopsis; KU 2088) and Wallace County mapped in Collins, 1982.
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. Results of second Kansas herp count held during April-May 1990. Kansas Herpetological Society Newsletter (81):10-12
1990 Collins, Joseph T. Maximum size records for Kansas amphibians and reptiles. Kansas Herpetological Society Newsletter (81):13-17
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 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 Collins, Joseph T. New records of amphibians and reptiles in Kansas for 1991. Kansas Herpetological Society Newsletter (87):12-17
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.
Joseph T. Collins third Kansas herpetology. <Need to get species total and principal differences with previous 'version' (= Collins 1982)>
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 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.
1998 Collins, Joseph T. New records of amphibians and reptiles in Kansas for 1997. Kansas Herpetological Society Newsletter (111):12-14
2001 Collins, Joseph T. New records of amphibians and reptiles in Kansas for 2000. Kansas Herpetological Society Newsletter (124):6-8
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.
2002 Ellis, Mark R. Fall 2002 KHS field trip to Washington County. Journal of Kansas Herpetology (2):4-5
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 Miller, Larry L. 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.
2010 Collins, Joseph T., Suzanne L. Collins, and Travis W. Taggart. Amphibians, Reptiles, and Turtles of Kansas Eagle Mountain Publishing., Provo, Utah. 400pp.
Joseph T. Collins fourth Kansas herpetology. <Need to get species total and principal differences with previous 'version' (= Collins 1993)>
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 Zimmer, Stephanie A. Implications of commercial harvest of river turtles in Missouri. Thesis. University of Missouri, Columbia, Missouri. 96pp.
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 Rohweder, Megan R. Kansas Wildlife Action Plan. Ecological Services Section, Kansas Department of Wildlife, Parks and Tourism in cooperation with the Kansas Biological Survey. 176pp.
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 Bass, Neil. Herpetological (Frog and Turtle) Inventories along the Missouri River in Kansas. Collinsorum 4(1):5-9
2015 Taggart, Travis W. Summer Field Trip In The Harvey County Sandhills. Collinsorum 4(3):3
2016 Powell, Robert, Roger Conant, and Joseph T. Collins. Peterson Field Guide to Reptiles and Amphibians of Eastern and Central North America. Houghton Mifflin Harcourt, Boston. 494pp.
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
2019 Johnson, Hunter. Geographic distribution: Apalone mutica: Colorado. Herpetological Review 50():522
2020 Daniel, Richard E. and Brian S. Edmond. Atlas of Missouri Amphibians and Reptiles for 2019. Privately printed, Columbia, Missouri. 86pp.
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
2020 Maloney, Max Geographic distribution: Apalone mutica mutica: Colorado. Herpetological Review 51(2):270
2021 Johnson, Hunter D. and Sean M. McMullen. Geographic Distribution: Apalone mutica: USA: Colorado: Prowers Co. Herpetological Review 52(3):572
Mentions nearest record to the east in Kearney County, Kansas.
2021 Plummer, Michael V. Natural History Notes: Apalone mutica: Predatory escape. Herpetological Review 52(3):624-5
Account Last Updated:
4/22/2021 9:14:58 AM