Graptemys oculifera
Males and females have dark olive shells with some yellow and orange spots on the scutes (scales). The scutes around the edge have yellow semicircle patterns and the under shell is yellow. The skin on the head and body is blackish with yellow stripes. There is a large yellow stripe on top of the head that runs from the tip of snout to behind the eyes. The legs have one or two stripes that run along their length. (Ernst, et al., 1994; Jones and Selman, 2009; Lindeman, 2000)
Females are much larger than males with an average length of 22 cm. The average length of males is 11 cm. The shells of both males and females are longer than they are wide. Males and females are also shaped slightly differences, females have smaller heads and males have larger tails and foreclaws. Young have a more round shell that is grey. (Ernst, et al., 1994; Jones and Selman, 2009; Lindeman, 2000)
Ringed map turtles are found only in the Pearl River system in Mississippi and Louisiana. They are most common in the main channel of the river, especially upstream of the Ross Barnett Reservoir, but they are also found in the lowest reaches and the largest tributary of the Bougue Chitto River. The total length of the river that is inhabited by these turtles is about 875 km. (ARKive, 2013; Jones and Hartfield, 1995)
Ringed map turtles prefer wide rivers, with either a clay or sandy bottom, that have moderate to strong currents. They require areas with abundant basking sites formed by debris and fallen trees. They are sometimes found in oxbow lakes that have clay or sandy lake beds. Females venture onto sandbars near the river channel when laying eggs.
Females deposit the eggs in nests that are about 29°C. The eggs hatch after about 64 days. After hatching, the young turtles remain in the nest for 12 days, then emerge and travel from the nest to the river. Young grow at about 8.4 mm per year, after two years they grow to 39 to 58 mm. After this, females grow faster than males. (Ernst, et al., 1994; Jones and Selman, 2009)
There is no information about the mating system of ringed map turtles in the literature.
Males begin to reproduce between their 3rd and 4th year, females begin to reproduce after 9 growing seasons. Mating occurs at the end of April and the eggs are laid in nests on sandbars from mid-May to mid-June. Females can reproduce up to two times a year, but usually just once, and lay from 1 to 10 eggs (usually 3 to 4). The young emerge from the nest in late July or early August.
Females nourish and carry the eggs, then place them in nests they construct along rivers. After hatching, the young are independent and there is no more parental care. (Jones, 2006)
A female in captivity lived 12 years and eight months. In the wild, females are expected to live between 31 and 37 years and males from 23.5 to 25.5 years. (Ernst, et al., 1994; Jones and Selman, 2009)
Ringed map turtles spend many hours during the day basking on fallen logs in the river channel. They rest on fallen branches at night just under the surface of the water. They are not active at night, except when hatchlings leave their nests. (Ernst, et al., 1994)
There is no information on home range size in ringed map turtles.
There is no information about communication or perception in ringed map turtles in the literature. However, like most turtles, they use vision, touch, and sense vibrations.
Ringed map turtles are omnivorous. They feed on plant material growing on the undersurfaces of logs and along the riverbanks, including algae and flowers (Asteraceae). They also feed heavily on adult and larval caddisflies, true flies, mayflies, snails, aquatic beetles and their larvae, dragonfly nymphs, and damselflies.
Predators usually prey on young turtles after they emerge from the nest. When disturbed, these turtles swim away, retreat into their shells, or empty their bladders on the predator.
This species is a consumer, as it feeds on plants, algae, and insects. It also serves as a host to some nematode species that are found in the turtle’s stomach and thought to be parasitic. (Ernst, et al., 1994)
There are no known adverse effects of ringed map turtles on humans.
Individuals are sometimes taken from the wild and kept as pets. (CITES, 2013)
Ringed map turtles are listed as vulnerable on the IUCN Red List and threatened under the United States Endangered Species Act. They are thought to be threatened by pollution, habitat destruction in their aquatic habitats, and the risk of very destructive hurricanes. Capture for the pet trade is also placing this species at risk. (CITES, 2013; International Union for Conservation of Nature and Natural Resources, 2013)
Kara Bonasia (author), The College of New Jersey, Keith Pecor (editor), The College of New Jersey, Tanya Dewey (editor), University of Michigan-Ann Arbor.
ARKive, 2013. "Ringed map turtle (Graptemys oculifera)" (On-line). ARKive. Accessed October 22, 2013 at http://www.arkive.org/ringed-map-turtle/graptemys-oculifera/.
CITES, 2013. "Consideration of Proposals for Amendment of Appendices I AND II" (On-line). CITES. Accessed October 25, 2013 at http://www.cites.org/eng/cop/10/prop/E-CoP10-P-59.pdf.
Ernst, C., J. Lovich, R. Barbour. 1994. Turtles of the United States and Canada. United States: Smithsonian Institution Press.
International Union for Conservation of Nature and Natural Resources, 2013. "Graptemys oculifera" (On-line). The IUCN Red List of Threatened Species. Accessed October 25, 2013 at http://www.iucnredlist.org/.
Jones, R., P. Hartfield. 1995. Population size and growth in the turtle Graptemys oculifera. Journal of Herpetology, 29: 426-36. Accessed October 20, 2013 at https://mail-attachment.googleusercontent.com/attachment/u/0/?ui=2&ik=c0ac8561f6&view=att&th=141e66f6269040c7&attid=0.1&disp=inline&safe=1&zw&saduie=AG9B_P_m4-VZJVIkIwSxFksRPlSx&sadet=1385081704178&sads=vKMY3SWJpJrXlF42GxU13_M98MM&sadssc=1.
Jones, R. 2006. Reproduction and nesting of the endangered ringed map turtle, Graptemys oculifera, in Mississippi. Chelonian Conservation and Biology, 5: 195-209. Accessed November 13, 2013 at http://illiad.davidson.edu/pdf/Lending_scans/110230517.pdf.
Jones, R., W. Selman. 2009. Graptemys oculifera (Baur 1890)- Ringed Map Turtle, Ringed Sawback. Conservation Biology of Freshwater Turtles and Tortoises, 5: 033.1-033.8. Accessed October 20, 2013 at http://www.iucn-tftsg.org/wp-content/uploads/file/Accounts/crm_5_033_oculifera_v1_2009.pdf.
Lindeman, P. 2000. Evolution of the relative width of the head and alveolar surfaces in map turtles (Testudines: Emydidae: Graptemys). Biological Journal of the Linnean Society, 69: 549–576. Accessed October 22, 2013 at http://ac.els-cdn.com/S0024406699903814/1-s2.0-S0024406699903814-main.pdf?_tid=33b0d222-5312-11e3-a806-00000aacb360&acdnat=1385082521_599f0361bbb8e327a93f5e823e875c09.