Meso-American Slider Turtle, Trachemys scripta venusta

Meso-American Slider Turtle, Trachemys scripta venusta. Photograph taken in the coastal region of Guatemala, March 2020. Photograph courtesy of Dr. Tom Bartol, Carlsbad, California.

Meso-American Slider Turtle, Trachemys scripta venusta. Photograph taken in the coastal region of Costa Rica, March 2023. Photograph courtesy of Dr. Tom Bartol, Carlsbad, California.

The Meso-American Slider Turtle, Trachemys venusta, is a member of the Emydidae family of Freshwater Pond and Marsh Turtles. Note: three subspecies of the Meso-American Slider Turtle are found in Mexico: the Huastecan Slider, Trachemys venusta cataspila, in the states of San Luis Potosí, Tamaulipas, and Veracruz; Gray’s Slider, Trachemys venusta grayi, in the states of Chiapas and Oaxaca; and the Yucatán Slider, Trachemys venusta iversoni, in the state of Yucatán. The Emydidae family consists of one-third of all extant species of turtles, with eighty-five  species placed into twenty-five genera. There are fifteen species in the Trachemys genus. The Meso-American Slider Turtle is known in Mexico as Tortuga Hicotea Mesoamericana.

Meso-American Slider Turtles have oval shells with sharp edges. Their shells are longer than they are wide with a low lateral profile. The dorsal side of their shell is rough with indentations that vary in direction, while the ventral side is flat and smooth. Their shells are olive to bright green in color with numerous dark-centered, orange-ringed spots on their plural scutes. Their skin is dark green and brown in color. They have yellow stripes on their head and legs, and a wide yellow or red blotch behind their eyes. They maintain these markings and colors from birth, except for very old males who become darker. Their heads are large and oblong, ending in a smooth snout that points upwards. Their nostrils are located high up on their snout. They have webbed feet, short flat forelimbs with five clawed digits, and short hind limbs. Both males and females have foreclaws that are used in courtship. Sexual dimorphism is displayed with males possessing longer foreclaws and tails than the females. However, females are more brightly colored and grow larger than the males, reaching up to 48 cm (19 inches) in length and 3.2 kg (7 lbs 0 oz) in weight. 

Meso-American Slider Turtles are gregarious and can be found in large numbers. They are largely aquatic, spending the majority of their day basking on logs and rocks. They are seldom far from water and will only leave their aquatic environment to nest and forage. During dry periods, they will migrate to areas that have water. They maintain a body temperature between 18℃ (65℉) and 33℃ (92℉), relying solely on basking to maintain the appropriate temperature. They have a relatively high tolerance for cold temperatures and are able to survive short cold weather periods as low as -14℃ (7℉). Their diet consists of carrion, fish, frogs, shrimp, water snakes, snails, tadpoles and aquatic vegetation such as duckweed. The juveniles are carnivores and as they mature, they add aquatic plants to their diets. In turn, they are preyed upon by alligators, armadillos, birds, catfish, coyotes, foxes, gars, opossums, otters, snakes and skunks. Their eggs are preyed upon by largemouth bass, deer, and foxes. In their defense, they have the ability to retreat into their shells by retracting their limbs and head. A few are even able to survive attacks by Alligators. They are generally non-aggressive and do not defend their home territories or their offspring.

Meso-American Slider Turtles reproduce during the warmer months and reproduction is oviparous. They are polygynandrous, with each female pairing with several males and each male pairing with several females. Mating occurs every 10 to 46 days during the breeding season. Females select a location to build a nest within 1.6 km (1.0 mi) of their aquatic home. Their nest is a simple oval-shaped hole that is 10 cm (4.0 in) to 14 cm (5.5 in) deep. Nests are dug in a variety of substrates and are typically constructed in the open to allow ample access to basking, making both the parents and their eggs at a greater risk of predation. Females will utilize the same nesting location on a continual basis. Each female lays 1 to 4 clutches per year, with each clutch consisting of 6 to 11 eggs. Once the eggs are deposited into the nests, no additional parental care is provided. Incubation lasts for 60 to 95 days before the eggs begin to hatch. Hatchings range in length from 2.3 cm (1.0 inch) to 3.5 cm (1.4 inches) and are miniature adults. Some hatchlings leave the nest almost immediately, while others stay in the nest for up to 10 months relying on the yolks from their eggs for sustenance. Juveniles who emerge later typically have higher survival rates than those who leave immediately.  The sex of hatchlings from a specific nest is temperature-dependent. Nests that are maintained below 29℃ (84℉) develop only males, while nests above 29.5℃ (85℉) develop only females. Nests at temperatures between 29℃ (84℉) and 29.5℃ (85℉) develop a mix of males and females. Juveniles develop in annual stages. Each year a new layer of scutes develop underneath the old one. They then molt and lose their old layer of scutes. When this process occurs, a growth line is left in the scute that can be used to determine a turtle’s age up to age  four. Meso-American Slider Turtles have life spans of up to  thirty years in the wild and over forty years in captivity.

Meso-American Slider Turtles are often confused with Chicken Turtles, Deirochelys reticularia (smooth, egg-shaped shells that are marked with a pale yellowish netlike pattern), and Painted Turtles, Chrysemys picta (two yellow spots behind each eye, and their shells are smooth on the edges with an olive to black carapace and an orange-yellow plastron that may be marked with red or yellow on the edges).

From a conservation perspective, the Meso-American Slider Turtle has not been formally evaluated. Due to the overexploitation of populations in Mexico, they have been placed within the “subject to special protection” category formulated by the Official Mexican Standard. In the state of Tabasco, Mexico, Management Units for the Conservation of Wildlife (UMA) were created to reduce the impact of overexploitation of freshwater turtles bred in captivity. Meso-American Slider Turtles are utilized by some cultures for human food and are considered a delicacy in China. They are in high demand and utilized extensively by the pet trade due to their color and adaptability to captivity. They will take food from the hand of the feeder but are also known to bite. They require large terrariums and a high level of maintenance. They have sharp claws and can be aggressive towards other turtles. Approximately 500,000 Meso-American Slider Turtles are exported alive from the United States to Japan each year. They have been introduced globally, and are considered to be highly invasive in many areas.