Description: Adult Cagle's map turtles have a minimum carapace length (CL) of 1.7 inches, making them one of the smallest map turtle species. Adult females can reach CL measures up to 8.6 inches and can more than double the size of the adult males (typically 2.75 to 4.75 inches). Males rarely exceed 5 inches.

They possess a somewhat flattened carapace. These turtles can be identified by the prominent V-shaped marking on the top of their head leading to their eye area. On the lower jaw they have a longitudinal yellow mark leading up to the transverse bar on the chin. Located on the top of the carapace, the spine is raised into vertebral scutes that almost come to a sharp point. The skin on their arms, legs, head, and tail is dark green, almost black, with yellow to cream colored stripes throughout. The shell is a dark yellow to brown with brown to black swirl-like markings on each scute of the shell. The yellowish plastron has black flecks and each scute has a black edging to it. On the posterior portion of the body, there are compressed knobs of vertebra numbers 2 and 3. Both sexes have almost flat plastrons. A major difference between the sexes is that males have a longer tail than females.

As hatchlings, the map turtles are about 1.25 inch CL. They have rounder shells than adults. Additionally, on the plastron, the lines around the scutes are more pronounced, but they lack the dark flecks that adults possess.

Habitat: Calge’s map turtles inhabit relatively large creeks and rivers with a sand, gravel, or mucky substrate. Shallow locales with moderate flow rates are common. Their basking locations include newly fallen trees, rocks, or even cypress (Taxodium) knees (pneumatophores). Cagle’s map turtles are commonly found at depths of 3 to 9 feet when submerged. They are equally common in riffles (fast-moving water) or pools (slow-moving water) in these waterways, though males often forage at transitional areas between riffles and pools.

Range: Calge’s map turtles (Graptemys caglei) are native to the San Antonio River (Texas, United States), which feeds into the Guadalupe River. These turtles are concentrated (60 to 82% of all individuals) along a 16.75 mile section of the middle Guadalupe River. They are less common in the upper (11% of all individuals) and lower (7%) Gualadupe.

The turtles can also be found in the San Marcos River. Counties in Texas that these turtles inhabit are: DeWitt, Kerr, Kendall, Comal, Guadalupe, Gonzales, DeWitt, Hays, and Victoria counties. It has also been stated that in the southern extent of Victoria county, this turtle reaches as close as 44 linear river miles to the Gulf of Mexico.

Found in these States: TX

Diet: Adult Cagle’s map turtle diets vary by sex. Adult females are molluscivores, consuming primarily snails (Order Gastropoda), Asian clams (Corbicula fluminea), and crayfish. Molluscs comprise 88% of their diet.

Adult males are primarily insectivores, consuming aquatic insects and smaller crustaceans. Included aquatic insect larva are from the orders Trichoptera (caddisflies), Ephemeroptera (mayflies), Odonata (dragonflies and damselflies), and Plecoptera (stoneflies). The remaining 15% of their diet is aquatic snails (Gastropoda).

Juveniles' diet varies by sex; young males consume snails and insects equally, while young females consume clams and insects equally. Plant matter is also consumed by males and juveniles by accident, as they are consuming the invertebrates on the plants.

Reproduction: Mating in Cagle's map turtles is thought to occur in late spring and early summer months, as ovulation by females begins in late April and continues through late July. They are considered polygynandrous, although females may be receptive to mating just once per season.

Mating behavior is not well described in the wild; in captivity, it has been stated that males court females by facing them and vibrating their head against the female's head region.

Cagle's map turtles breed in spring and summer months, with nesting reported from late March until late August. Females dig nests in sandy areas, but when sand is less available, they can also place them in clay loam or sandy-gravel locales.

Females may have one, two, or three clutches per season, and the number of eggs per clutch is 1 to 6. Clutch size is correlated with female size. Females travel 6 to 35 feet from the edge of the river. They choose nests that are 1.5 to 3 feet above the water level to minimize nest flooding. The young are fully independent upon hatching, and have been found on the landscape from September through November. Males are reported to reach sexual maturity, at 2 to 3 years of age. Females reach maturity at a large size and later age, but age has not been reported.

Status: Cagle's map turtles are currently listed as "Endangered" on the IUCN Red List. Like all map turtles in the genus Graptemys, they are listed in CITES under Appendix III, which means that they need regulation in trade on an international scale. Often export permits are granted for these animals. Texas lists Cagle’s map turtles as state-threatened; as result of that the turtles cannot be taken, transported, or sold in the state. Private breeders on the outside of Texas are the reason these turtles are available in the U.S trade of pets. They have no special status on the US Federal list, although they were considered for listing in 2006. The listing was denied because it was deemed that that conservation efforts at the state level were sufficient to protect Cagle's map turtles.

Subspecies: None

Taxonomy: