Description
Species Name- The name Apalone spinifera is widely used, and may now be the accepted name for this species.
Other Taxonomic Groupings - Seven subspecies are known over this species' native range, from southeasternmost Quebec and VT (St. Lawrence Valley, Lake Champlain), MN, west to WY, CO, and south to Mexico, with a disjunct population in MT (Ernst et al. 1994). Most specimens reported in the Chesapeake region appear to be Trionyx spiniferus spiniferus, native to the eastern Mississippi Valley, upper Great Lakes-St. Lawrence Basin, but a population of Trionyx spiniferus asper, native to the South and Gulf coastal plains (NC-LA; Webb 1962) was found in Lake Whitehurst, Norfolk VA (Mitchell and Southwick 1993).
Potentially Misidentified Species - Apalone ferox, native from AL to SC, and FL, is a potential introduction in the Chesapeake Bay region.
Taxonomy
| Kingdom | Phylum | Class | Order | Family | Genus |
|---|---|---|---|---|---|
| Animalia | Chordata | Reptilia | Testudines | Trinonychidae | apalone |
Synonyms
Invasion History
Chesapeake Bay Status
| First Record | Population | Range | Introduction | Residency | Source Region | Native Region | Vectors |
|---|---|---|---|---|---|---|---|
| 1953 | Unknown | Unknown | Introduced | Regular Resident | North America | North America | Ornamental(Pet Release) |
History of Spread
Apalone spinifera (Spiny Soft-Shelled Turtle) is native to the Interior Basin and Atlantic and Gulf Slopes of southeast North America, from the Lake Champlain region Quebec-VT west to MT south to FL-NM and Mexico. Atlantic Slope populations range from FL to southernmost NC. Seven subspecies are known, of which at least 2, A. s. spiniferus and A. s. asper have been introduced into the Chesapeake Bay region (Ernst et al. 1994). Apalone spinifera was apparently once used commonly for food (Carr 1952; Webb 1962), and young ones are occasionally taken as pets. It has been introduced to the Colorado River drainage in AZ and CA, to several coastal CA drainages (USGS Florida Caribbean Science Center 2001), to the Maurice River (Salem County) NJ, a Delaware Bay tributary (Ernst et al. 1994), to the Hudson River drainage, via the Erie Canal (Webb 1962) and Eastern MA-RI (USGS Florida Caribbean Science Center 2001). Populations in the lower Colorado Basin and the Maurice River appear to be established (Ernst et al. 1994).
Chesapeake specimens seem to be isolated, released individuals, with no evidence of breeding (McDiarmid 1996, Gotte 1996, personal communications), except possibly for the Lake Whitehurst, Norfolk and Windsor (VA) populations. However, given the frequency of occurrence, present or future establishment of this species cannot be ruled out.
James River, Lower Bay- Apalone spinifera asper (3 adults, 3 juveniles, and a hatchling) were collected from Lake Whitehurst,in Norfolk VA, 1991. Apalone spinifera spiniferua (5 adults, 1 juvenile) were taken from Windsor VA, Isle of Wight County (James River drainage), at Perry's Minnow Farm, in 1991 (Mitchell and Southwick 1993).
Potomac - An early attempt to introduce A. spinifera into the Potomac River was made by Dukehart (1884). He captured 18 turtles from the Ohio River, near Moundsville WV, and released them in the Potomac River near Cumberland MD, and planned to release more in 1884. This introduction is presumed to have failed, and the later records are believed to have resulted from individual releases (Mansueti and Wallace 1960). An Apalone sp. was sighted at Mason Neck VA in 1982-84 (McDiarmid 1996), and another one was caught in Bull Run Creek, Manassas VA in 1982 (Mitchell 1994). In 2007, a specimen of A. spinifera was caught at the mouth of the Occoquan River, where it joins the tidal Potomac (Mitchell et al. 2007).
Patuxent River - A single turtle captured and released at Patuxent Naval Air Station, St. Marys County MD, 1991 was probably a released pet (Rambo 1992). Another specimen was captured in the Patuxent River near Jug Bay in May 2003 (Paul Fofonoff, personal observation).
Upper Bay and Tributaries - A single A. spinifera was caught by a crabber in at the head of the Rhode River, (Now part of the Smithsonian Environmental Research Center), Edgewater MD in 1953 (Mansueti and Wallace 1960).
Susquehanna River - There were unconfirmed reports of Apalonex sp. in the Susquehanna, but no specimens have been captured in this river. (Roddy 1928, cited by Mansueti and Wallace 1960; Webb 1962).
History References - Dukehart 1884; Ernst et al. 1994; Gotte 1996 Mansueti and Wallace 1960; McDiarmid 1996; Mitchell 1994; Mitchell and Southwick 1993; Rambo 1992;Florida Caribbean Science Center 2001; Webb 1962
Invasion Comments
Population Status - Chesapeake Bay tidal records appear to be entirely or primarily isolated individuals, with no evidence of breeding, so 'Failed' might be an appropriate designation. However, several breeding individuals were found close to tidal waters (Mitchell and Southwick 1993), supporting the status of 'unknown'.
Ecology
Environmental Tolerances
| For Survival | For Reproduction | |||
|---|---|---|---|---|
| Minimum | Maximum | Minimum | Maximum | |
| Temperature (ºC) | 0.0 | 41.0 | ||
| Salinity (‰) | 0.0 | 8.0 | 0.0 | |
| Oxygen | ||||
| pH | ||||
| Salinity Range | fresh-meso |
Age and Growth
| Male | Female | |
|---|---|---|
| Minimum Adult Size (mm) | ||
| Typical Adult Size (mm) | ||
| Maximum Adult Size (mm) | ||
| Maximum Longevity (yrs) | ||
| Typical Longevity (yrs |
Reproduction
| Start | Peak | End | |
|---|---|---|---|
| Reproductive Season | |||
| Typical Number of Young Per Reproductive Event |
|||
| Sexuality Mode(s) | |||
| Mode(s) of Asexual Reproduction |
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| Fertilization Type(s) | |||
| More than One Reproduction Event per Year |
|||
| Reproductive Startegy | |||
| Egg/Seed Form |
Impacts
Economic Impacts in Chesapeake Bay
Apalone spinifera (Spiny Softshell Turtle) was first introduced, unsuccessfully, to the Chesapeake Bay watershed as a food animal (Dukehart 1884), but later occurrences seem to have resulted from the release of individual 'adopted' animals. This turtle does not seem to have been part of the pet baby-turtle trade of the mid-20th century. This species is possibly established in Chesapeake drainage (Mitchell and Southwick 1993), but has no reported economic impact.
References- Dukehart 1884; Mitchell and Southwick 1993
Economic Impacts Outside of Chesapeake Bay
Apalone spinifera (Spiny Softshell Turtle) was locally used as food in its native range (Carr 1952), but rarely sold in cities (Webb 1962). These turtles were often killed in the mistaken belief that they harm fish populations (Ernst et al. 1995).
References - Carr 1952; Ernst et al. 1995; Webb 1962
Ecological Impacts on Chesapeake Native Species
Trionyx spiniferus (Spiny Softshell Turtle) does not appear to be widely established at this time, although two possible breeding populations have been reported in southeast VA (Mitchell and Southwick 1993). Effects on native turtle populations are unlikely at this time.
References- Mitchell and Southwick 1993
Ecological Impacts on Other Chesapeake Non-Native Species
Trionyx spiniferus (Spiny Softshell Turtle) does not appear to be widely established at this time, although two possible breeding populations have been reported in southeast VA (Mitchell and Southwick 1993). Competitive effects on introduced Trachemys scripta (Red-Eared Slider) populations are unlikely, since T. spiniferus has a more carnivorous diet (Ernst et al. 1994).
Refences- Ernst et al. 1994; Mitchell and Southwick 1993
References
Carr, Archie (1952) Handbook of Turtles: The Turtles of the United States, Canada, and Baja California, , Ithaca, NY. Pp.Dukehart, J. P. (1884) Transfer of soft-shell terrapin from the Ohio to the Potomac River, Bulletin of the U.S. Fish Commission 4: 143
Ernst, Carl H.; Barbour, Roger W.; Lovich, Jeffrey E. (1994) Turtles of the United States and Canada, , Washington, DC. Pp.
Mansueti, Romeo, Wallace, David H. (1960) Notes on the soft-shell turtle (Trionyx) in Maryland waters, Chesapeake Science 1: 71-72
Mitchell, Joseph C. ; Steury, Brent W.; Buhlmann, Kurt A.; van Dijk, Peter Paul (2007) Chinese softshell turtle (Pelodiscus sinensis) in the Potomac rRver and notes on eastern spiny softshells (Apalone spinifera) in northern Virginia, Banisteria 30: 41-43
Mitchell, Joseph C., Southwick, Ronald (1993) Notes on the spiny softshell, Apalone spinifera (Testudines: Trionychidae), in southeastern Virginia, Brimleyana 18:
Rambo, Kyle (1992) A specimen of the eastern spiny soft-shelled turtle, Apalone spinifer spinifer (LeSeur) from St. Mary's County, Maryland., The Maryland Naturalist 36: 3-4
Seidel, Michael E. (1975) Osmoregulation in the turtle Trionyx spiniferus from brackish and freshwater, Copeia 1975: 124-128
2003-2024 Nonindigenous Aquatic Species Database. Gainesville, FL. http://nas.er.usgs.gov
Webb, Robert G. (1962) North American recent soft-shelled turtles (family Trionychidae), Museum of Natural History, University of Kansas Publications 13: 429-611