Graptemys oculiferaRinged Map Turtle

Geographic Range

Graptemys oculifera is endemic to the Pearl River system in Mississippi and Louisiana. It is most common in the main channel of the Pearl River, especially upstream of the Ross Barnett Reservoir, but is also found in the lowest reaches and the largest tributary of the Bougue Chitto River. The total length of the river the turtle inhabits is about 875 km. (ARKive, 2013; Jones and Hartfield, 1995)

Habitat

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 from debris and fallen trees. On occasion, individuals have been found in oxbow lakes in the same region that have clay or sandy lake beds. Females venture into terrestrial areas when laying eggs. This occurs on sandbars adjacent to river channels. It has been documented that these sandbars are 39% sand, 38% herbaceous vegetation, and 23% woody vegetation. (ARKive, 2013; Ernst, et al., 1994)

  • Aquatic Biomes
  • rivers and streams

Physical Description

The carapace of males and females is dark olive with some yellow and orange spots on the scutes (scales). The scutes around the perimeter of the carapace show a yellow semicircle pattern and the under shell is yellow. Skin on the head and body is blackish with yellow strips. There is a large yellow stripe found on top of the head that runs from the tip of snout to behind the eyes. There are also lateral stripes that sometimes connect with the larger central stripe. The legs have one or two stripes dorsally, ventrally, and laterally. The carapace has flattened spines on vertebral scutes 1 to 4. The spines on vertebral scutes 1 and 4 are smaller and directed strongly posterior, whereas those on vertebral scutes 2 and 3 are larger and directed moderately posterior. (Ernst, et al., 1994; Jones and Selman, 2009; Lindeman, 2000)

Females are much larger than males with an average carapace length of 22 cm. The average carapace length of males is 11 cm. The carapace in both males and females is longer than it is wide. The smallest recorded plastron (bottom part of shell) length of a male was 55.8 mm. There are some physical differences between males and females other than body size. Females are microcephalic with narrow heads. Males have a more pronounced tail, a more narrow head, and larger foreclaws. Offspring show slightly more resemblance to adult males than adult females, but generally the characteristics are the same. Offspring have an almost round carapace that is more grey in color than that of an adult. Also, spines on offspring are more posterior directed than on adults. (Ernst, et al., 1994; Jones and Selman, 2009; Lindeman, 2000)

  • Sexual Dimorphism
  • female larger
  • sexes shaped differently

Development

Females deposit the eggs in nests that are about 29°C. The eggs are approximately 39x24 mm and hatch after an average of 64 days. Just before emerging from the shell, the claws and shell margins are covered with gelatin-like sheath. After hatching the turtles remain in the nest for a short period, 12 days, and then emerge and travel from the nest to the river. Hatchings have a plastron length of 22.3 to 32.7 mm and are on average 9.5 g - 80.1% of freshly laid egg weight. For both juvenile males and females, the growth rate is approximately 8.4 mm/yr. In the beginning of the first growing season, juveniles are 35.7 to 53.7 mm long, and they grow to 39 to 58 mm in the second growing season. After this point and until sexual maturity, females grow at a faster rate than males. (Ernst, et al., 1994; Jones and Selman, 2009)

  • Development - Life Cycle
  • temperature sex determination

Reproduction

There is no information about the mating system of ringed map turtles in the literature.

Males and females become sexually mature at different ages. Males become sexually mature during the third or fourth season of growth, whereas females mature after nine seasons. Although there is little information about mating, it occurs at the end of April during the daytime. The gestation period is about two and a half weeks, and eggs are laid in nests on sandbars from mid-May to mid-June with the peak occurring in mid-June. The nests are 30 mm in diameter and depth, and are found 7 to 17.4 m from the edge of the river and close to vegetation. Females can lay up to two clutches a year, but they usually only lay one. Clutch size ranges from 1 to 10 eggs, with an average of 3 to 4 eggs. Offspring emerge from the nest in late July to early August after sunset and travel from the nest to the river. (Ernst, et al., 1994; Jones and Selman, 2009; Jones, 2006)

  • Breeding interval
    Females may lay two clutches a year. The annual clutch frequency is 1.10.
  • Breeding season
    Eggs are laid from mid May to mid July with the peak in mid June.
  • Range number of offspring
    1 to 10
  • Average number of offspring
    3.66
  • Average gestation period
    2.5 weeks

Females invest more than males during offspring development. Females invest in and carry the eggs for about two and a half weeks and create the nests before depositing the eggs. (Jones, 2006)

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)

  • Parental Investment
  • female parental care
  • pre-fertilization
    • provisioning
    • protecting
      • female
  • pre-hatching/birth
    • provisioning
      • female
    • protecting
      • female

Lifespan/Longevity

There has been little research on ringed map turtles in longevity, but systematic recapturing of individuals has lead to some conclusions. 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 23.5 to 25.5 years. (Ernst, et al., 1994; Jones and Selman, 2009)

  • Typical lifespan
    Status: wild
    27.25 to 31.25 years

Behavior

Ringed map turtles spend many hours during the day basking on fallen logs or debris in the river channel. When individuals are basking in groups, they tend to face in different directions to maximize visibility. Individuals rest on snags or fallen branches at night just under the surface of the water. They are not nocturnally active; the only time this is observed is when hatchlings leave the nest. (Ernst, et al., 1994)

Home Range

There is no information on home range size in ringed map turtles.

Communication and Perception

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.

Food Habits

Ringed map turtles are omnivorous. They feed on plant material growing on the undersurfaces of logs, a majority being algae and flowers belonging to the family Asteraceae. They also feed heavily on adult and larval caddisflies (Trichoptera), true flies (Diptera), mayflies (Ephemeroptera), snails (Gastropoda), aquatic beetles and their larvae (Coleoptera), dragonfly nymphs (Odonata), and damselflies (Odonata). (Ernst, et al., 1994)

  • Animal Foods
  • insects
  • mollusks
  • Plant Foods
  • flowers
  • algae

Predation

Predation on nests and juveniles is very high. Offspring loss in the nest is due to terrestrial predators, including raccoons, fish crows, and armadillos. In addition, many nests are attacked just after pipping (breaking of the egg during hatching) by an ant species (Solenopsis molesta) that is a relative of the red ant. When in danger or being disturbed the turtle’s first defense is to flee or protect itself in the shell. It may also bite or release bladder water if held. (Ernst, et al., 1994; Jones and Selman, 2009)

Ecosystem Roles

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)

Commensal/Parasitic Species

Economic Importance for Humans: Positive

Individuals are sometimes taken from the wild and kept as pets. (CITES, 2013)

Economic Importance for Humans: Negative

There are no known adverse effects of ringed map turtles on humans.

Conservation Status

Ringed map turtles are listed as vulnerable on the IUCN Red List as of August 2010. Populations remain stable or in decline due to threats of pollution, sedimentation, habitat loss through channel size decrease, and weather (hurricane) effects. Human destruction of the habitat is also negatively affecting populations of these turtles. Capture for the pet trade is likely to also negatively impact populations. This species is considered threatened throughout its range under the United States Endangered Species Act. (CITES, 2013; International Union for Conservation of Nature and Natural Resources, 2013)

Contributors

Kara Bonasia (author), The College of New Jersey, Keith Pecor (editor), The College of New Jersey, Tanya Dewey (editor), University of Michigan-Ann Arbor.

Glossary

Nearctic

living in the Nearctic biogeographic province, the northern part of the New World. This includes Greenland, the Canadian Arctic islands, and all of the North American as far south as the highlands of central Mexico.

World Map

bilateral symmetry

having body symmetry such that the animal can be divided in one plane into two mirror-image halves. Animals with bilateral symmetry have dorsal and ventral sides, as well as anterior and posterior ends. Synapomorphy of the Bilateria.

diurnal
  1. active during the day, 2. lasting for one day.
ectothermic

animals which must use heat acquired from the environment and behavioral adaptations to regulate body temperature

female parental care

parental care is carried out by females

freshwater

mainly lives in water that is not salty.

heterothermic

having a body temperature that fluctuates with that of the immediate environment; having no mechanism or a poorly developed mechanism for regulating internal body temperature.

iteroparous

offspring are produced in more than one group (litters, clutches, etc.) and across multiple seasons (or other periods hospitable to reproduction). Iteroparous animals must, by definition, survive over multiple seasons (or periodic condition changes).

motile

having the capacity to move from one place to another.

natatorial

specialized for swimming

native range

the area in which the animal is naturally found, the region in which it is endemic.

omnivore

an animal that mainly eats all kinds of things, including plants and animals

oviparous

reproduction in which eggs are released by the female; development of offspring occurs outside the mother's body.

pet trade

the business of buying and selling animals for people to keep in their homes as pets.

seasonal breeding

breeding is confined to a particular season

sedentary

remains in the same area

tactile

uses touch to communicate

temperate

that region of the Earth between 23.5 degrees North and 60 degrees North (between the Tropic of Cancer and the Arctic Circle) and between 23.5 degrees South and 60 degrees South (between the Tropic of Capricorn and the Antarctic Circle).

threatened

The term is used in the 1994 IUCN Red List of Threatened Animals to refer collectively to species categorized as Endangered (E), Vulnerable (V), Rare (R), Indeterminate (I), or Insufficiently Known (K) and in the 1996 IUCN Red List of Threatened Animals to refer collectively to species categorized as Critically Endangered (CR), Endangered (EN), or Vulnerable (VU).

vibrations

movements of a hard surface that are produced by animals as signals to others

visual

uses sight to communicate

References

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.