Red-eared Slider

Type Description

Trachemys scripta elegans (WIED 1838) – Red-eared Slider Turtle has a prominent broad red postorbital stripe, narrow jaw stripes, yellow stripes on their skins, and a shell pattern consisting of dark spots or single blotches on each scute (Ernst, 1990; Figure 5 1). The shell length of the Red-eared slider turtle ranges from 125 mm to 350 mm (Ernst et al., 1994, Somma & Fuller, 2009). The upper shell and skin are olive to brownish-green with yellow stripes or spots (Scalera, 2006). Newly hatched and young individuals have a greenish upper shell (carapace), yellow lower shell (plastron), and green, yellow stripes, and spots on their skins. These patterns and colors on the skin and shell fade with age. The upper shell (carapace) varies from light olive green to orange-brown or brown, and the plastron is dull yellow or darker with age. In young turtles, the carapace is keeled (having ridges down the center of each scute), but this feature gradually disappears with age. In adult Red-eared slider turtles, males have much longer front claws than females, while females generally have shorter, thinner tails than males (Scalera, 2006; Ernst and Lovich, 2009).

Habitat

"Red-eared slider turtles spend their time searching for food in dense vegetation in pools or basking on logs (Figure 5 1). They prefer stagnant waters with soft, muddy bottoms, aquatic plants, and suitable basking areas. In their natural range, the species inhabits a wide variety of freshwater habitats, including rivers, ditches, marshes, lakes, and ponds (Bringsøe, 2006). The Red-eared slider turtle prefers large stagnant water bodies with soft bottoms, abundant aquatic plants, and suitable basking areas (Ernst et al., 1994; Bringsøe, 2006).

Distribution: The species' natural distribution is in the eastern United States and northeastern Mexico. It covers the Mississippi Valley from Illinois to the Gulf of Mexico, including 19 states in the United States (Alabama, Arkansas, Florida, Georgia, Illinois, Indiana, Iowa, Kansas, Kentucky, Louisiana, Mississippi, Missouri, Nebraska, New Mexico [east], Ohio, Oklahoma, Tennessee, Texas, West Virginia) and two states in Mexico (Nuevo Leon, Tamaulipas) (Ernst, 1990).

Foreign Populations: Feral populations occur throughout Mexico; in some parts of the United States (Arizona, California, Hawaii Islands, northeastern states); Guadeloupe (France): Grande Terre and Basse Terre; Portugal: widespread, especially in the south; Spain: widespread at low altitudes; France: widespread except in the north; Italy (distributed throughout the country); Slovenia (near the Italian border); Greece (Crete); Austria (Vienna region); Germany; southwestern Switzerland; the Netherlands; Turkey; Israel; South Africa; Taiwan; Thailand; Cambodia; Indonesia; and Australia (van Dijk et al., 2011).

In Turkey, the Red-eared slider turtle has been observed in the provinces of Istanbul, Çanakkale, İzmir, Balıkesir, Manisa, Muğla, Denizli, İzmit, Adapazarı, Düzce, Bolu, Eskişehir, Ankara, Aksaray, Antalya, Mersin, Adana, Osmaniye, Samsun, Tunceli, Trabzon, Artvin, Diyarbakır, Kırklareli, Sinop, and Bartın. However, the species has been observed to form or tend to form populations especially in the provinces of İzmir, Muğla, Antalya, Adana, and Mersin.
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Reproductive Information

Males can reach a shell length (CL) of 24 cm, while females can reach 29 cm. Maturity is reached at approximately 9-11 cm CL, and males reach this size in two to five years, while females reach maturity at 15-20 cm CL in five to eight years. The maximum lifespan is 30 years, with a reproductive period likely lasting 12-15 years. Depending on body size and other factors, females lay eggs 1-6 times a year, each clutch containing around 30 eggs. Natural populations typically lay 6-11 eggs per nest on average (Bringsøe, 2006; Scalera, 2006). The eggs are oval-shaped, 31-43 mm long, 19-26 mm wide, and weigh 6.1-15.4 grams (Bringsøe, 2006). The incubation period lasts 59-112 days (Scalera, 2006). The incubation period of the species depends on weather conditions. The suitable temperature is between 22 °C and 30 °C for 55 to 80 days (Pendlebury, 2006; Pupins, 2007). Eggs hatch in 50-60 days at 26 °C. Hatchlings have a shell length of 23-35 mm (Thomas, 2006; Ernst and Lovich, 2009). Their lifespan varies between 20 and 50 years. The Red-eared slider turtle can live approximately 40 years (Scalera, 2006). Therefore, even if they do not reproduce, they can survive in natural environments for years.

Lifecycle

The Red-eared slider turtle can live approximately 40 years (Scalera, 2006). Therefore, even if there is no reproduction within the introduced range, they can remain there for years.

Nutrition Information

Trachemys scripta is omnivorous, feeding on a variety of plant and animal prey. The species consumes a wide range of invertebrates (crustaceans, snails, insects), vertebrates (fish, frogs, lizards, snakes, birds, rodents), and plants (algae, ferns, seed plants) (Ma and Shi, 2017).

General Impact Information

"At the end of World War II, the demand for Red-eared Slider turtles as pets increased significantly, leading to a booming commercial turtle farming industry in the United States and subsequently large-scale exports to many countries (Bringsøe, 2006). So far, this turtle has spread to more than 70 countries and regions in Europe, Africa, Oceania, Asia, and America (Kraus, 2009; Rhodin et al., 2017; Figure 5 2).

Individuals that survive the first year or two generally live for about 30 years. They pose a risk of infection, particularly Salmonella. This risk can be reduced and minimized by changing the aquarium water at least every two weeks for juveniles and weekly for adults, or by using an appropriate aquarium water filtration system. When they reach adulthood, they can cause painful bites and irresponsible owners may release them into the wild, leading to negative ecological, social, and economic impacts (Csurhes and Hankamer, 2016).

The Red-eared Slider is considered a significant threat to native turtle species because it matures and grows faster, produces more offspring, and is more aggressive. Many studies provide evidence that Red-eared Sliders can compete with native turtles for basking, nesting, and sunning areas (Cadi and Joly, 2004; Polo-Cavia et al., 2010). As an omnivorous species, they also have negative effects on many native aquatic forms as they consume plants as well (O'Keefe, 2005).

In conclusion, their competition with native species, competition with endangered species, being a disease vector, their feeding habits, the risk of carrying diseases that threaten public health, and their unpredictable effects on natural habitats and ecosystems are significant concerns."

General Management Information

There is no established management approach yet.

General Pathway Information

"Since the 1970s, a large number of young Red-eared Slider turtles (T. scripta) have been produced on turtle farms in the United States for the pet trade. The most exported subspecies, the Red-eared Slider T. S. elegans, was produced for foreign markets more than 52 million times between 1989 and 1997 (Telecky 2001, Cadi et al. 2004). As Red-eared Sliders (T. scripta) are often sold at small sizes (3-4 cm shell length), unsuspecting turtle owners are rarely prepared to continue keeping them in captivity when they reach adulthood (up to 30 cm shell length) (Cadi et al. 2004). Most of the time, turtles that reach more adult sizes are released into the wild by their owners. This has led to many Red-eared Sliders entering natural ecosystems (Cadi et al. 2004). The interest in pet turtles may have peaked in the late 1980s and early 1990s during the Teenage Mutant Ninja Turtle cartoon craze (Somma and Fuller 2009).

Entry and spread routes in Turkey: The Red-eared Slider turtle enters Turkey through the pet trade. Companies engaged in the pet trade sell individuals that have just hatched and are 3-4 cm in shell length. Turtles, which are often adopted by people who are not sufficiently knowledgeable about the species' biology, are released into the wild after a while, primarily due to rapid growth and other reasons. Additionally, they are released into artificial or natural water sources in parks and gardens for visual purposes. In this way, abandoned individuals and those in natural water sources eventually form healthy populations that reach sufficient numbers and attempt to breed under suitable climate conditions."

Notes

The Red-eared Slider turtle is an opportunistic omnivorous species with a strong competitive ability. This turtle can adapt to various environments, whether they are lakes, reservoirs, or muddy pools, ditches, or even brackish waters in estuaries; we can see them in almost all polluted and clean waters. It has become one of the world's top 100 widespread invasive species. On the one hand, the species has a wide niche, various physiological activities tolerant to different ecological factors, and even some environmental stresses. On the other hand, it has strong behavioral adaptation and flexibility, allowing it to adjust and change itself to adapt to and thrive in any environmental conditions.

References