Eastern River Cooter
Pseudemys concinna concinna

Common Name:

Eastern River Cooter

Scientific Name:

Pseudemys concinna concinna

Etymology:

Genus:

Pseudemys is derived from the Greek word pseudes which means "false" and emys which means "turtle".

Species:

concinna is derived from the Latin word concinnus meaning "well arranged or beautiful".

Subspecies:

concinna is derived from the Latin word concinnus meaning "well arranged or beautiful".

Average Length:

9 - 12 in. (23 - 30.6 cm)

Virginia Record Length:

12.2 in. (31 cm)

Record length:

12.8 in. (32.2 cm)

PHYSICAL DESCRIPTION: The river cooter is a large freshwater turtle mainly occurring in riverine habitats. They can reach a maximum carapace length of 420 mm (16.5 inches). Virginia's maximum known carapace length is 310 mm, maximum plastron length is 297 mm, and maximum body weight is 3700 grams. Carapace is long and oval, with a weakly serrated posterior margin. The scutes of the carapace are set up in 12 marginals on each side, 4 pleurals on each side and 5 vertebrals. The plastron is hingeless and about three quarters of the size of the carapace. The carapace is brown with a touch of green in some specimens and is marked in yellow to cream. The most prominent marking is a backwards c-shaped figure bordered in black/brown on the second pleural scute. This marking may occur on additional scutes in some individuals. The 'c' faces posteriorly and is right next to the seam between scutes. This is the only patterning that has any consistency. Other markings may include: dorsum of marginals bears a dark area, sometimes comprised of concentric circles, and often a yellowish transverse bar; venter of marginals bears several dark spots with yellowish centers - these spots border the edge of the shell and are usually divided by the seams of the marginal scutes; bridge with one to several dark spots on the axillary and inguinal scutes. The plastron is usually yellowish and has a highly variable, narrow, dark markings that follows the seams - most of the figure is confined to the anterior portion of the plastron in some adults. This pattern may not be visible on all adults. Skin color is brown to olive with yellow lines on head and limbs. Top of head has a short yellow line that extends to the tip of the snout. Other head markings include:a pair of thin lines bisected by the short line extends posteriorly forming a violi pattern; an oblique stripe lies above and behind the eye and another one that parallels it directly behind the eye; chin and neck stripes wider than head stripes; the upper one forks over the upper and lower jaws and the chin stripes usually meet anteriorly; >11 lines on head and neck behind the ear. There are usually no cusps on the upper jaw, but some individuals have weakly formed cusps *10760,11624,11407*. This species is quite sexually dimorphic. Females are generally larger than males with a carapace length of 265-310mm compared to the males 190-256mm. The elongated tail in males (precloacal distance avg. = 42.8+/-4.0 mm, 37-47, n=11) extends the anal opening beyond the posterior edge of the carapace. The anal opening in females does not extend beyond the carapace. Males have elongated foreclaws *10760,11624*. Juveniles are variable but resemble adults in general pattern. The carapace at hatching is keeled and has a greenish tint with yellow markings (colors are brighter). The C-shaped mark may not be present. The only consistant character is the dark pattern along the seams of the anterior plastron scutes. Virginia hatchings are 31.9-36.8 mm carapace length (avg. = 34.1+/-1.5, n=29), 28.0-34.1 mm plastron length (avg. = 31.2+/-1.8), and weigh 6.8-11.0 g (avg. = 8.7+/-1.2) *10760*. River cooters may be confused with Pseudemys rubriventris which have a single, wide, vertical bar on each pleural scute, and prominent cusps on the upper jaw. Pseudemys concinna floridana has <11 lines on the head and neck, and lack the Chrysemys picta have 2 yellow spots behind each eye and a light transverse bar across the entire carapace *10760,11624,11407*.

REPRODUCTION: Reproduction has been little studied in P. concinna. Nests are placed in sandy soil less than 30 m from water. Females with oviductal eggs were found in Virginia on 16 June and 1 July. One contained 20 oviductal eggs, 9 enlarged follicles, and 2 sets of corpora lutea, suggesting she laid 2 clutches. Other records include a Chesterfield county nest that contained newly emerged hatchlings on Sept. 23. Laboratory hatching dates were Sept. 1 and Oct. 4. Clutch size in Virginia is 12-20 eggs (avg. = 15.6+/-3.9, n=4). Eggs averaged 36.5+/-1.3 x 24.5+/-0.9 mm (length 34.2-39.7, width 23.4-26.1, n=31) and weighed 11.6-15.4 grams (avg. = 12.7+/-1.2). Incubation is typically 84-92 days in the southern U.S. *10760,11624,11284*.

BEHAVIOR: These turtles are mainly active from March through November when the temperature is at least 18 degrees celsius. They are usually active only during the day and are very skittish, leaving their basking sites at the slightest provocation. They are primarily plant eaters but will scavenge on crayfish, dead fish and asian clams (Corbicula fluminea). They do not usually travel on land except to nest. They are not commonly seen and don't seem to be very gregarious. They can breathe without breaking the surface of the water when cold *10760,11624,11284*.

ORIGIN: The river cooter is native to Virginia *10760*.

POPULATION PARAMETERS: The population ecology of P. concinna in Va. has not been studied. Research in WV found that population size estimates for turtles in 3 pools were 14-23. Linear growth of adults was 2.4 mm per month for females and 6.00 mm per month for males. One hatchling grew 30 mm in 139 days. Predation of juveniles is mainly by bass, snakes, snapping turtles, raccoons, minks and foxes *10760*.

AQUATIC/TERRESTRIAL ASSOCIATIONS:This species is mainly found in large slow moving rivers (hence their name). Preferred characteristics include abundant aquatic vegetation, basking sites, and shelter for overwintering. *10760* *11284*.

Life History Comments: Additional study of the life history and ecology of this species would be beneficial *10760*.

References for Life History

  • 1027 - Carr, A.F., 1952, Handbook of Turtles. Turtles of the United States, Canada, and Baja California, 542 pgs., Comstock Publ. Assoc., Cornell Univ. Press, Ithaca, NY
  • 1102 - Cochran, D.M., C.J. Goin, 1970, The new field book of reptiles and amphibians, 359 pgs., G.P. Putman's Sons, NY
  • 10760 - Mitchell, J. C., 1994, The Reptiles of Virginia, 352 pgs., Smithsonian Institution Press, Washington, DC
  • 11284 - Wilson, L.A., 1995, Land manager's guide to the amphibians and reptiles of the South, 360 pp. pgs., The Nature Conservancy, Southeastern Region, Chapel Hill, NC
  • 11407 - Conant, Roger and, Collins, John T., 1998, Peterson Field Guide: Reptiles and Amphibians, Eastern/Central North America, 616 pgs., Houghton Mifflin Company;, Boston
  • 11624 - Mitchell, J. C., 2001, Personal Communication, Expert review for GAP Analysis Project, Mitchell Ecological Research LLC

Photos:

*Click on a thumbnail for a larger version.


Verified County/City Occurrence

Albemarle County
Amelia County
Appomattox County
Botetourt County
Brunswick County
Campbell County
Caroline County
Charles City County
Charlotte County
Chesterfield County
Cumberland County
Danville City
Dinwiddie County
Fairfax County
Fredericksburg City
Greensville County
Halifax County
Hanover County
Henrico County
Mecklenburg County
Montgomery County
Nelson County
Newport News City
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Pittsylvania County
Powhatan County
Prince Edward County
Prince George County
Prince William County
Pulaski County
Radford City
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Richmond County
Roanoke City
Rockbridge County
Russell County
Scott County
Verified in 37 Counties/Cities.



FROGS

Virginia is home to 28 species of frogs and toads.

SALAMANDERS

We have a large diversity of salamanders consisting of 56 different species and subspecies.

LIZARDS

Virginia is home to 9 native lizard species and two introduced species, the Mediterranean Gecko and the Italian Wall Lizard.

SNAKES

The Commonwealth is home to 34 species and subspecies of snake. Only 3 species are venomous.

TURTLES

Virginia has 25 species and subspecies of turtle. Five of these species are sea turtle.