CENTRAL AMERICAN RIVER TURTLE: Dermatemydidae

PHYSICAL CHARACTERISTICS

The only living Central American river turtle, which has the scientific name Dermatemys mawii, is a large animal with a small head and a pointy snout. It has a dark-colored, somewhat flat upper shell, or carapace (KARE-a-pays). The carapace of adults is thick, heavy, and smooth. It is so smooth that is almost looks like it is made of leather. The yellow- or cream-colored lower shell, or plastron (PLAS-trun), is large, as is the bony bridge that connects the upper and lower shells. The feet are webbed. Females and males look similar, but females are generally larger. In addition, the upper surface of a male's head has a large yellowish gold patch, while females as well as juveniles (JOO-vuhnuhl), or the young, have gray on the top of the head. The biggest Central American river turtles can weigh as much as 49 pounds (22 kilograms) and have a carapace as long as 26 inches (66 centimeters).

GEOGRAPHIC RANGE

Central American river turtles live in Mexico, Guatemala, and Belize.

HABITAT

Although some of them may wander into somewhat salty water, Central American river turtles live mainly in freshwater, such as rivers and large lakes. The turtles live in the lowlands of southern Mexico near the Gulf of Mexico. They also live in Belize and northern Guatemala, and possibly in Honduras.

DIET

Central American river turtles eat mostly plants. They prefer figs and other fruits as well as leaves that fall into the water from the trees lining the shoreline. They also eat plants that grow in the water and sometimes an insect, fish, or mollusk (MAH-lusk). Mollusks are soft-bodied animals covered by a shell, such as snails and clams.

BEHAVIOR AND REPRODUCTION

Central American river turtles spend most of their lives in the water. Turtles have lungs and breathe air, but the Central American river turtle is able to stay underwater for long periods of time. In the rare instances when the turtles do leave the water, they are very slow, awkward walkers. They sometimes float in the surface waters on sunny days to soak up some heat, but they do not leave the water, as many other turtles do, to sunbathe, or bask. Besides floating near the surface on warm days, the turtles do little during the day. They become active at night, when they do most of their feeding.

THE TURTLE OF MANY NAMES

Besides Central American river turtle, this animal has other common names, including hickety in Belize; jicotea, tortuga plana, and tortuga aplanada in Mexico; and tortuga blanca in Mexico and Guatemala. The word "blanca" means "white" in Spanish and refers either to the white underside of the turtle or to the color of its meat. Some people refer to this turtle as the Mesoamerican (MEH-soh-American) river turtle. Mesoamerican is the word used to describe the culture of Mexico and northern Central America before the Spanish explorers arrived.

Central American river turtles mate anytime from March to September. For the most part, the only time the turtles leave the water is during the nesting season, which starts in September, when the rainy season is in full force. The turtles nest any time from September to December, but some females start as early as late August or wait until March or April. When she is ready to lay her eggs, the female walks a few feet onto the shore, usually no more than 10 feet (3 meters), and digs a hole. She lays two to twenty brittle-shelled eggs that are about 2.1–2.8 inches (53–71 millimeters) long and 1.2–2 inches (30–51 millimeters) wide and weigh about 1.2–2.5 ounces (34–71 grams) each. A typical nest has eight to fourteen eggs. The female buries the eggs under mud and bits of rotting, nearby plants. The mother turtles usually produce two nests a year, but some have only one nest, and others may make three or four nests each season. Usually the largest females lay the most eggs in a year, and the smallest females lay the fewest. Because female Central American river turtles lay their eggs so close to the water, during the rainy season the lake or river can overflow onto the shore and flood the nests. The good news is that the eggs can survive being underwater for up to one month. The eggs need about seven to ten months to hatch, and most hatch anytime from late May to July, just when the rainy season starts up. As happens with many other kinds of turtles, warmer nest temperatures turn most Central American river turtle eggs into female hatchlings, or newly hatched young, and cooler temperatures produce males. The warm or cool weather has to occur when the eggs are about halfway along in their development.

CENTRAL AMERICAN RIVER TURTLES AND PEOPLE

Many local people in southern Mexico, northern Guatemala, and Belize consider the meat of Central American river turtle a delicacy and also collect the eggs. Even though these turtles are protected in some areas, hunting continues and threatens the survival of the species.

CONSERVATION STATUS

Both the World Conservation Union (IUCN) and the U.S. Fish and Wildlife Service label the Central American river turtle as Endangered, or facing a very high risk of extinction in the wild or throughout all or a significant portion of its range. Some governments have protected these turtles, which makes hunting or collecting them illegal.

FOR MORE INFORMATION

Books:

Burnie, David, and Don E. Wilson, eds. Animal: The Definitive Visual Guide to the World's Wildlife. United Kingdom: Dorling Kindersley, 2001.

Lee, Julian C. The Amphibians and Reptiles of the Yucatán Peninsula. Ithaca, NY: Comstock, 1996.

Web sites:

"Family Dermatemydidae (Mesoamerican River Turtles)." http://www.embl-heidelberg.de/uetz/families/Dermatemydidae.html (accessed on August 7, 2004).

Lowry, H. 2001. "Dermatemys mawii." Animal Diversity Web. http://animaldiversity.ummz.umich.edu/site/accounts/information/Dermatemys_mawii.html (accessed on August 7, 2004).

"Mexico Coalition Launches Strategy to Stop Destruction of Country's Richest Forest." Conservation International. http://www.conservation.org/xp/news/press_releases/2003/062603.xml (accessed on August 7, 2004.

"Turtle, Central American River." U.S. Fish and Wildlife Service. http://ecos.fws.gov/species_profile/SpeciesProfile?spcode=C04H (accessed on August 7, 2004).