Trachemys scripta

History of Spread

Trachemys scripta (Common Slider) consists of between 13 and 19 subspecies, over this species' native range, from southeasternmost VA, IA and KS south to Brazil. The three major United States subspecies have all been introduced to the Chesapeake drainage (Cooper 1959; Ernst et al. 1994; Manusueti 1941). Trachemys s. scripta (Yellow-Bellied Slider) ranges from southeast VA to FL, T. s. troosti (Cumberland Slider) is found in eastern TN and K, and T. s. elegans (Red-Eared Slider) is found in the Mississippi Valley, from OH, IL and KS to the Gulf of Mexico (AL-TX)(Carr 1952; Ernst et al. 1994). One subspecies ,T. s. scripta, is native to the southernmost part of the Chesapeake watershed, north to VA Beach, the southern border of the lower James drainage and the tip of the VA Peninsula (Mitchell 1994).

Adult T. scripta, were apparently shipped from the Mississippi valley to the Eastern seaboard to be sold as 'terrapins' for food during the late 1800's, there is a record from the Philadelphia Market in 1890 (Gotte 1996). However, widespread introduction of this species seems to have occurred mostly in the 20th century. Juveniles of T. scripta (particularly T. s. elegans) were widely captured and shipped throughout the United States and the world by the pet trade from the 1930's or earlier to the 1970's (Carr 1952; Ernst et al. 1994; Warwick et al. 1990). In 1975, the Food and Drug Administration banned shipment of turtles less than 4 cm in carapace length, because of risks of Salmonella infection, but juvenile T. scripta continue to be exported to other countries (1-2 million per year, Warwick et al. 1990). Up to 765,000/year may still be shipped to the Far East, largely for food. Adults are still extensively used in laboratories for research and teaching, and may be sometimes released when not needed (Warwick et al. 1990). Introductions within the species range have resulted in frequent hybridization of subspecies (Ernst et al. 1994).

In North America, Trachemys scripta (primarily T. s. elegans) has been introduced to at least 12 states outside its native range (USGS Florida Caribbean Science Center 2001). Trachemys scripta is established in the San Francisco Bay Delta (Cohen and Carlton 1995) and the Hudson River Basin (New York State Department of Environmental Conservation 2000).

Chesapeake drainage records are listed below:

Lower Bay Drainages - Intergrades between T. s. scripta and T. s. elegans are known from Virginia Beach, Chesapeake, Suffolk, and James City Counties, where T. s. scripta is native (Mitchell 1994).

James River Drainage -There are several records of T. s. elegans from the vicinity of Richmond (Mitchell 1994).

Potomac River - One specimen of T.s. scripta was captured in the C&O canal at Little Falls; 1956 (Cooper 1959). Many T. s. elegans were many present in a 'turtle pond' display at Great Falls nature lodge; released annually at end of summer (Cooper 1961). Thirteen T. s. elegans were collected from a pond in Frederick County and Monocacy River; with additional records from Prince George County and Washington DC (Groves 1972). Trachemys scripta (mostly T. s. elegans) is naturalized in the MD and DC area (Ernst et al. 1994), and common at Kenilworth Aquatic Gardens, on the Anacostia River (Fofonoff, personal observation). At least two subspecies have been seen nesting at Mason Neck VA, and there have been many scattered sightings at reservoirs in Fairfax County (Gotte 1996).

Patuxent River - One specimen (T. s. elegans) was in an indoor turtle display at Battle Creek Cypress Swamp Nature Center, Patuxent Drainage, Calvert County, and was caught in a nearby pond according to the park naturalist (Fofonoff 1996 personal observation).

Upper Bay and Drainages - Trachemys s. troosti has been reported from south and northwest Baltimore City and Patapsco State Park (Glen Artney). 'Young specimens are sold by the thousands in pet shops and department stores, and certainly many have been liberated' (Mansueti 1941). A population of T. s. troosti and T. s. elegans was found in Lake Roland, Baltimore County, and captures or sightings of T. scripta in the Gunpowder River, Loch Raven Reservoir, Prettyboy Reservoir, and Lake Wagner (Glen Burnie) were reported by Cooper (1959; 1961). A specimen of T. scripta elegans was captured at the Smithsonian Environmental Research Center weir, Rhode River, Edgewater MD in June 1994 (Hines et al. unpublished data; Steelman 1995 personal communication).

Eastern Shore Tributaries - Trachemys s. elegans is established in Wicomico River and is common (Grogan 1994).

History References - Carr 1952; Cohen and Carlton 1995; Cooper 1961; Ernst et al. 1994; Gotte 1996; Grogan 1994; Groves 1972; Mansueti 1941; Mitchell 1994; New York State Department of Environmental Conservation 2000; Steelman 1995 personal communication; Warwick et al. 1990

Invasion Comments