Red Ear Slider (Trachemys scripta elegans), Schoepff, 1792
IDENTIFICATION: 5-12 inches (**-** cm). The carapace is oval from a dorsal perspective and there may be serrated edges present on the rear marginal scutes. Among mature specimens, the carapace contains numerous longitudinally oriented shallow ridges. These become more pronounced as the turtle grows older. A low mid-dorsal keel is also present on the carapace. A broad red stripe is present behind the eye. However, this colorful mark like other color markings becomes faded with advanced age. Females are the larger of the sexes.
Juveniles are the most colorful with yellow lines interlacing a lime green base coloration. As the turtle grows the yellow lines become less pronounced. Adults often disply yellow lines, but they are much finer and less distinguished than those present on juveniles.
Mature males posses a longer and wider tail with a cloacal opening that extends beyond the posterior margin of the carapace. Males also develop elongated fore claws that are used in underwater courtship behavior to vibrate water currents alongside the female's ears.
Reproductive behavior usually takes place between March to August and begins with the male courting the female. All reproductive activity with the exception of egg laying takes place in the water. Courtship behavior involves the male orienting himself in front of the female face to face. He then extends his front legs until the elongated front claws are aligned next to her tympanum. Then with rapid movements in his wrist he gently strums the water alongside her head. Courtship may take up to one hour to complete. Should the female be receptive to his advances copulation ensues. The male then orients himself behind the female and mounts the posterior portion of her carapace where he can align his cloaca with hers. Mating usually only requires 10 to 15 minutes.
Females lay three clutches of 1-30 eggs from April to August. Clutch size depends upon the size of the female. Hatching generally requires between 60 to 90 days. The sexes of red eared sliders are determined by their incubation temperature.
Although they are considered to be the most abundant and common species of freshwater turtle in Texas, red ear sliders still face challenges from the form of human activities ranging from habitat loss , pollution and trapping for Chinese food markets while the eons -old pressure of nest being raided by predators continues.
After hatching, red ear sliders are primarily carnivorous however, their dietary preference shifts towards vegetative matter as they mature. Adults primarily consume aquatic vegetation such as duckwed, algae, hyacinth, and various other aquatic plants. Because of this, red ear sliders are important for for aquatic ecology by keeping waterways clear of excess and sometimes invasive aquatic vegetation. Even though adults are primarily vegetarian they are still opportunisitc for other types of food items and will not hesistate to consume a variety of invertebrates and small vertebrates which include but are not limited to: worms, snails, crayfish, insects, arachnids, small amphibians, reptiles, birds and mammals. It is an inaccurate notion that this turtle poses a threat to fish populations. Most healthy fish are toofast and wary to be caught by the red ear slider and the removal of any old or sick fish is a manner by which the overall health of the remaining fish population is improved. Sliders will also consume carrion that has fallen into the water. Not only are these attractive turtles interesting to observe and study but they provide a beneficial service to man by improving the quality of waterways.
A comparison of male and female red ear sliders of various ages all from the San Saba River in central Texas. The upper left and second upper left are comparison photos between the red ear slider and Texas map turtle
These are some examples of melanistic male red ear sliders. When males reach the same size as the females they lose their green coloration and shift toward darker shades. Black, browns and grays adorn the body and even conceal the trademark red ear