Introduction to Turtles
Water turtles have webbed feet and spend most of their time in water, although many like to bask on logs and rocks. They are mainly carnivorous (meat-eaters), but often eat vegetable matter. In the United States, the sale of turtles with a carapace length less than 4" is prohibited by federal law. Juvenile turtles caught in the wild and turtles hatched in captivity are not covered by this law unless sold. This account is limited to common North American aquatic turtles.
Pond and marsh turtles include many familiar North American species of the genera Graptemys, Chrysemys, Malaclemys, Clemmys, Thrachemys [Pseudemys], Deirocheiys, and Emydoidea. The common names of this group include map turtles, painted turtles, diamondback terrapins, pond turtles, cooters, redbelly turtles, sliders, chicken turtles and Blanding's turtles. There are many differences in habitat, diet and lifestyles of these turtles. Use a field guide to distinguish which kind(s) you have. Earnst and Barbour (1989) offer habitat and life history notes in every account. There are some shared characteristics: they bask and need a "haul-out" place with a temperature gradient; the water should be maintained between 75-85°F (24-30°C) year-round; they are usually more carnivorous as juveniles than as adults, and they all make good pets. Diamondback terrapins (Malaclemys) live in brackish (salty water) and eat shellfish. Owners should plan carefully before undertaking this type of turtle. Some species of these are in trouble in the wild. Care should be taken that no threatened or endangered animals are added to your collection without proper permits.
Snapping turtles, genera Chelydra and Macroclemys, are aggressive and can inflict a nasty bite. Large snappers are not recommended for first time keepers or small children. Baby snappers make nice pets, but have the potential to grow to large size, so plan ahead. They are strictly carnivorous and seldom bask.
Mud and musk turtles, genera Sternatherus and Kinosteron, have glands, associated with the bridge between the upper and lower shells, which secrete a smelly fluid, earning them the common names of "stinkpot" and "musk turtles." They are strictly meat eaters. In the wild, they often bask on branches or other projections several feet above the water, or in shallow water with only the central portion of the shell exposed.
An aquarium works best. Water should be as deep as the shell is long, and preferably deeper, except for bottom dwelling species including snapping turtles, softshell turtles, musk and mud turtles. Turtles also require a dry "haul-out" area for rest and basking. This can be a platform of plastic, rock, brick, cork, bark, or driftwood. It must be large enough for the turtle to emerge completely from the water, and it must be secured so it won't topple and trap the turtle under water. An ultraviolet light source such as Vita-lite/ZooMed ReptiSun is recommended for vitamin D synthesis. (See handout on Ultraviolet Light.) To prevent bite wounds different types or sizes of turtles should not be housed together. Aggressive individuals will require private aquaria. Turtles climb surprisingly well, so be sure that your cage is escape proof.
Room temperature is not warm enough for normal metabolism during winter months, nor cool enough for hibernation. Winter hibernation requires exact environmental conditions and can be risky for the animal. It is better to provide supplemental heat in the winter. Keep the water between 75-85°F (24-30°C). Submersible aquarium heaters (available at most pet stores) work best. If an aquarium hood or cover is used, the heat from the water heater along with the light in the hood itself may be enough, because the hood holds heat in the tank. If the top is open, the temperature of the air can be raised with a light bulb or heat lamp focused on part of the "haul-out" area. This will satisfy the turtle's instinctive requirement to bask in the sun. Use a timer, or turn the light off at night. Alternatively, the whole room can be heated, although this is often not economical. Remember the temperature will go down when the light goes off. Use a thermometer to be sure the proper temperature is maintained day and night.
Pre-formed aquatic turtle foods are available. An alternative is Purina Trout Chow. It is a complete and balanced dry pellet food formulated for farm-raised trout. Turtles thrive when pre-formed foods are used as a major portion of the diet. It can be dropped in the tank like fish food, or soaked first to soften it. Some turtles will refuse it at first, but will accept it after continued exposure. Don't give up on it too soon.
Greens such as mustard, collard, beet, turnip, endive, romaine, spinach, kale, or seaweed can be offered. Be aware that plants from a pond may carry snails, small worms, or insects that may thrive in the aquarium and be difficult to eradicate. Many juvenile turtles love duckweed. Avoid iceberg lettuce. Many kinds of turtles are carnivorous as juveniles but eat more plant material as they grow. The greens mentioned can be supplemented with apples, watercress, and other vegetables. Supplement the diet with a complete multivitamin/mineral. Use a reptile or bird vitamin and make sure that the vitamin D is listed as vitamin D3 rather than D2 or plain D. Growing turtles need extra calcium for proper shell hardness. Pet Cal and Osteo-Form are chewable calcium tablets and turtles will eat small pieces dropped in the water.
Crayfish can transmit the bacteria, Beneckia chilinovora, which can cause shell lesions in turtles and should not be fed to turtles.
In the wild, turtles inhabit large ponds or rivers in which their uneaten food and wastes are diluted to safe levels. In captivity, aquariums trap these wastes and foster the build-up of pathogenic bacteria, fungi, and algae, often to dangerous levels. Prevent soiling of the aquarium in the first place. Feed the turtle in a separate bucket/pail or container so the water in the tank does not become fouled with food particles. Remove visible wastes quickly with a dip net. Turtle bowel movements are large and promote bacterial growth so fast that frequent changes alone cannot keep water clean. A good filtration system is essential.