Red-eared slider

Red-eared slider
Trachemys scripta elegans (Wied-Neuwied). Engraving made in 1865 by Karl Bodmer, who accompanied the authority on his expedition.
Conservation status
Least Concern  (IUCN 2.3)
Scientific classification
Kingdom:	Animalia
Phylum:	Chordata
Class:	Reptilia
Subclass:	Anapsida
Order:	Testudines
Family:	Emydidae
Genus:	Trachemys
Species:	T. scripta
Subspecies:	T. s. elegans
Trinomial name
Trachemys scripta elegans (Wied-Neuwied, 1839)

The red-eared slider (Trachemys scripta elegans) is a semiaquatic turtle belonging to the family Emydidae. It is a subspecies of pond slider. It is the most popular pet turtle in the United States and also popular in the rest of the world. It is native only to the southern United States, but has become established in other places because of pet releases.

Name

Red-eared sliders are popular pets around the world.

Red-eared sliders get their name from the distinctive red mark around their ears. The "slider" part of their name comes from their ability to slide off rocks and logs and into the water quickly. This species was previously known as Troost's turtle in honor of an American herpetologist; Trachemys scripta troostii is now the scientific name for another subspecies, the Cumberland slider.

Behavior

Red-eared slider basking on a floating platform under a sunlamp

Red-eared sliders are almost entirely aquatic, but leave the water to bask in the sun and lay eggs. These reptiles are deceptively fast and are also decent swimmers. They hunt for prey and will attempt to capture it when the opportunity presents itself. They are aware of predators and people, and generally shy away from them. The red-eared slider is known to frantically slide off rocks and logs when approached.

Contrary to the popular misconception, red-eared sliders do not have saliva. They, like most aquatic turtles, have fixed tongues, so they must eat their food in water.

Description

The female red-eared slider grows to be 25–33 cm (10–13 in) in length and males 20–25 cm (8–10 in). The red stripe on each side of the head distinguishes the red-eared slider from all other North American species. The carapace (top shell) is oval and flattened (especially in the male), has a weak keel that is more pronounced in the young, and the rear marginal scutes are notched. The carapace usually consists of a dark green background with light and dark highly variable markings. The plastron (bottom shell) is yellow with dark, paired, irregular markings in the center of most scutes. The plastron is highly variable in pattern. The head, legs, and tail are green with fine, yellow, irregular lines. Some dimorphism occurs between males and females. Male turtles are usually smaller than females but their tail is much longer and thicker. Claws are elongated in males which facilitate courtship and mating. Typically, the cloacal opening of the female is at or under the rear edge of the carapace, while the male's opening occurs beyond the edge of the carapace. Older males can sometimes have a melanistic coloration, being a dark grayish-olive green, with markings being very subdued. The red stripe on the sides of the head may be difficult to see or be absent.

Diet

Red-eared sliders are omnivores and eat a variety of animal and plant materials in the wild including, but not limited to, fish, crayfish, carrion, tadpoles, snails, crickets, wax worms, aquatic insects and numerous aquatic plant species. The captive diet for pet red-eared sliders should be a varied diet consisting of invertebrates such as worms, aquatic and land plants, and other natural foods. They should never be fed commercial dog food or cat food. Calcium (for shell health) can be supplemented by adding pieces of cuttlebone to the diet, or with commercially available vitamin and mineral supplements. A nutritious food readily accepted by young turtles is baby clams soaked in krill oil covered with powdered coral calcium. Younger turtles tend to be more carnivorous (eat more animal protein) than adults. As they grow larger and older, they become increasingly herbivorous. Live foods are particularly enjoyed and add to the quality of life of captive turtles. Providing a wide variety of foods is the key to success with captive red-eared sliders. For pet red eared slider turtles, one can feed them treats occasionlly, like shrimp, chicken, cucumbers, or tomatoes. Larger turtles have been known to prey upon younger turtles.

Hibernation

Reptiles do not hibernate, but actually brumate, becoming less active, but occasionally rising for food or water. Brumation can occur in varying degrees. Red-eared sliders brumate over the winter at the bottom of ponds or shallow lakes; they become inactive, generally, in October, when temperatures fall below 10 °C (50 °F). Individuals usually brumate under water. They have also been found under banks and hollow stumps and rocks. In warmer winter climates, they can become active and come to the surface for basking. When the temperature begins to drop again, however, they will quickly return to a brumation state. Sliders will generally come up for food in early March to as late as the end of April. Red-eared sliders kept captive indoors should not brumate. To prevent attempted brumation in an aquarium, lights should be on for 12–14 hours per day and the water temperature should be maintained between 24 and 27 °C (75 and 81 °F). Water temperatures must be under 13 °C (55 °F) for aquatic turtles to brumate properly. Controlling temperature changes to simulate natural seasonal fluctuations encourages mating behavior.

Reproduction

Hatching turtle with its egg-tooth.

Female laying eggs in a nest she dug out with her hind legs

Courtship and mating activities for red-eared sliders usually occur between March and July, and take place under water. The male swims toward the female and flutters or vibrates the back side of his long claws on and around her face and head. The female swims toward the male and, if she is receptive, sinks to the bottom for mating. If the female is not receptive, she may become aggressive towards the male. The courtship can take up to 45 minutes, but the mating itself usually takes only 10 to 15 minutes.

Sometimes a male will appear to be courting another male. This is actually a sign of dominance, and they may begin to fight. Juveniles may display the courtship dance, but until the turtles are five years of age, they are not mature and are unable to mate.

After mating, the female spends extra time basking to keep her eggs warm. She may also have a change of diet, eating only certain foods or not eating as much as she normally would. Mating begins in May and egg-laying occurs in May through early July. A female might lay from two to 30 eggs, with larger females having larger clutches. One female can lay up to five clutches in the same year, and clutches are usually spaced twelve to thirty-six days apart. The time between mating and egg laying can be days or weeks.

Hatching

Eggs hatch 60 to 90 days after they have been laid. Late season hatchlings may spend the winter in the nest and emerge when the weather warms in the spring. Just prior to hatching, the egg contains 50% turtle and 50% egg sac.

A new hatchling breaks open its eggs with its egg-tooth, which falls out about an hour after hatching. This egg tooth never grows back. Hatchlings may stay inside their eggshells after hatching for the first day or two. When a hatchling decides to leave the shell, it has a small sac protruding from its bottom plastron. The yolk sac is vital and provides nourishment while visible and several days after it has been absorbed into the turtle's belly.

Damage or motion enough to allow air into the turtle's body results in death. This is the main reason for marking the top of turtle eggs if their relocation for any reason is required. An egg that has been turned upside down will eventually terminate the embryo growth by the sac smothering the embryo. If it manages to reach term, the turtle will try to flip over with the yolk sac, which allows air into the body cavity and death follows. The other fatal danger is water getting into the body cavity before the sac is absorbed completely and the opening has not completely healed yet. It takes 21 days between the egg opening until water entry.

The sac must be absorbed, and does not fall out. The split may be noticeable in the hatchling's plastron on turtles found in the field, indicating the age of the turtle to be about three weeks old. The split must heal on its own before allowing the turtle to swim. However, this does not mean there is no need for moisture throughout the first three weeks of life outside of the egg. A good idea is to place the hatchlings on moist paper towels. The eggs should be kept on the moist towels from the day they are laid (dig them up an hour after being laid) and covered with toweling until they hatch and can swim. The turtle can also suck the water it needs from the toweling. Red-ear slider eggs matriculate in South Florida in 91 days while in New York City the egg takes 102 days. Turtles which were relocated exhibited this effect with constancy.

As pets

Trachemys scripta elegans

The red-eared slider, often sold cheaply, is the most common type of water turtle kept as pets. As with other turtles, tortoises and box turtles, individuals that survive their first year or two can be expected to live almost as long as their owners. Individuals of this species have lived at least 35 years in captivity.

Red-eared sliders can be quite aggressive—especially when food is involved. If being kept as a pet, care must be taken to prevent injury or even death of its smaller tankmates. However, the opposite can occur if shrimp are introduced as food. Smaller red-eared sliders less than a year old have been known to choke on the shells of the shrimp and suffer from lung puncture.

United States federal regulations on commercial distribution

A 1975 U.S. Food and Drug Administration (FDA) regulation bans the sale (for general commercial and public use) of turtle eggs and turtles with a carapace length of less than 4 inches (100 mm). This regulation comes under the Public Health Service Act, and is enforced by the FDA in cooperation with state and local health jurisdictions. The ban was enacted because of the public health impact of turtle-associated Salmonella. Turtles and turtle eggs found to be offered for sale in violation of this provision are subject to destruction in accordance with FDA procedures. A fine of up to $1,000 and/or imprisonment for up to one year is the penalty for those who refuse to comply with a valid final demand for destruction of such turtles or their eggs.

Many stores and flea markets still sell small turtles due to an exception in the FDA regulation which allows turtles under 4 inches (100 mm) to be sold "for bona fide scientific, educational, or exhibitional purposes, other than use as pets."

As with many other animals and inanimate objects, the risk of Salmonella exposure can be reduced by following basic rules of cleanliness. Small children must be taught to wash their hands immediately after they finish "playing" with the turtle, feeding it, or changing the water.

U.S. state law

Some states have other laws and regulations regarding possession of red-eared slider because they can be an invasive species where they are not native and have been introduced through the pet trade. As of July 1, 2007, it is illegal in Florida to sell any wild type red-eared slider, as they interbreed with the local yellow-bellied slider population – Trachemys scripta scripta is another subspecies of pond sliders, and intergrades typically combine the markings of the two subspecies. However, unusual color varieties such as albino and pastel red-eared sliders, which are derived from captive breeding, are still allowed for sale.

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Ideal conditions in captivity

• High water quality - Even with powerful filters, frequent water changes are needed. The water should be heated and maintained at approximately 78-82°F(~26-28°C). Room temperature water is not sufficient and can lead to disfigurement and respiratory ailments.
• Ultraviolet B lighting is required for indoor turtles. While an ideal habitat provides real, unfiltered sunlight, UVB lighting is a necessity in habitats without. Glass or plastic between the bulb and the basking area will prohibit natural and artificial UVB light from entering the habitat. The bulb should be placed above the turtle's basking area.
• Hibernation or brumation is not possible indoors at room temperature. Twelve hours of light per day helps prevent brumation.
• Mature female turtles not kept with males can lay infertile eggs. Females can also remain fertile for several years after a mating and lay fertile eggs. Mature females must have a desirable land area in which to lay eggs. Laying eggs in water is not healthy.
• Dystocia (egg binding), the inability to lay eggs due to tank confinement with insufficient or undesirable land areas, shell deformities or nutritional imbalances, is potentially fatal.
• Groups of turtles should have sex ratios of at least two females per male to avoid mating pressure, stress and injuries from overmating.
• Red-eared sliders in captivity (indoor) should be kept in large terrariums. A 10-20 gallon (40-80 liter) tank is sufficient for hatchling red-eared sliders, although they will quickly outgrow them. Much larger tanks are required for adult turtles. A commonly-used guideline is 10 gallons (40 l) of water per 1 inch (2.5 cm) of shell (example: a turtle of 5 inches (13 cm) and a turtle of 8 inches (20 cm) together need 130 gallons (500 l) of space).
• Red-eared sliders should not be kept in a tank with gravel or decorations that the turtle can fit in its mouth, as this can lead to bowel impaction and death. Commonly and cheaply available 20-grit sand (pool filter sand) makes an ideal substrate.
• Basking platforms or stabilized stacks of rocks should be provided so red-eared sliders can climb out of the water and dry off completely. The ideal basking surface temperature is 85-95ºF.

Environment

A line of basking red-eared sliders faces an inquisitive mallard.

A male red-eared slider in an outdoor pond with goldfish and koi

Red-eared sliders enjoy large areas where they are free to swim. These turtles also require a basking area, where they can completely leave the water and enjoy the light provided for them. UVB heat lamps are usually the best option and most common among those taking proper care of their turtles. However, UVB heat lamps have not been proven to have the same quality as direct, unfiltered UV rays from the sun. Turtles are recommended to be given time outdoors on days with more sun, even if this is only possible in the spring and summer.

For the basking area, the best choice is a dirt or sand area, if at all possible. Since these turtles like to climb, flat rocks also make good basking areas, as well as provide areas for entertainment.

Plant life, either fake or real, also increases red-eared slider quality of life, mimicking their natural environment. The real plants can also serve as a source of food.

Turtles enjoy fresh, clean and clear water. A good filter can help accomplish this. Also, once every two weeks, about 25% of the water should be removed and replaced with new water, and the filter cleaned. It is also strongly recommended to keep fast freshwater fish if the tank is large enough and the water has the proper pH and temperature. In a large enough tank with areas for fish to hide, it is very unlikely they will be eaten. Meanwhile, the majority of freshwater fish will feed on the leftover turtle feed, which allows for a much cleaner environment for both the turtles and the fish. They do not fare well in confined quarters, especially when overcrowded with hatchlings. They have been known to be cannibalistic. Certain species of fresh-water fish are also useful in consuming mosquito larvae, which may appear in outdoor enclosures.

Neurophysiology

Extensive research into the workings of the red eared sliders' brains has been performed at Saint Louis University by Prof. Michael Ariel.

In popular culture

Within the second volume of the Tales of the Teenage Mutant Ninja Turtles comic the four Turtles are revealed as specimens of the red-eared slider. The popularity of the Turtles led to a craze for keeping them as pets in Great Britain.

It was speculated that people often disposed of unwanted turtles by releasing them into the toilet, including in areas where they do not occur naturally, risking upsetting the originally balanced ecosystem of those particular areas. As a result, red-eared sliders have been considered one of the top 100 invasive species today

Further reading

• Maximilian zu Wied-Neuwied: Verzeichnis der Reptilien welche auf einer Reise im nördlichen America beobachtet wurden. Nova Acta Acad. CLC Nat. Cur. 32, I, 8, Dresden 1865 (With 7 illustrations by Karl Bodmer. Also: Frommann, Jena.)
• Maximilian zu Wied-Neuwied: Maximilian Prince of Wied’s Travels in the Interior of North America, during the years 1832 – 1834. Achermann & Comp., London 1843-1844 (Translation by H. Evans Lloyd).

External links

• Red-ear slider
• Discovery Channel's Animal Planet: Red-eared slider
• Information on aquatic turtles & tortoises including a few articles specific to Red-eared Terrapin
• Gulf Coast Turtle & Tortoise Society: Natural History: Red-eared slider