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Care: Aqautic and Semi-Aquatic Turtles

Image of midland painted turtleBasics of Captive Care

Although it is almost always best to study and enjoy turtles in their native habitats, there are times when keeping and observing captive turtles may offer educational, scientific, or other benefits. The following information is offered so people wishing to keep turtles will understand the basic health needs of these animals; however, we do not endorse the routine capture or purchase of wild-caught turtles for pets.

Recommended Species:

These species are fairly hardy and relatively common.

Note: Don't mix turtles of different sizes in the same captive set-up, and don't keep Snapping Turtles with other species!

Protected Species:

The following are fully protected in Michigan and may not be collected or possessed.

Note: Always check current State laws before collecting turtles or any wild animal.

Species Not Recommended:

These species are more difficult to keep, potentially dangerous, or grow too large.

Note on Collection

Image of common musk turtle (juvenile)Wild populations of turtles should be protected and their habitats preserved. Collecting one or two specimens of common species for temporary educational use in home or school will probably do no harm, but plan on releasing healthy specimens back into their original habitat as soon as observations are complete or interest wanes. Buying wild-caught animals from pet dealers or biological supply firms is strongly discouraged, and is often illegal. The collection of turtles or other reptiles for commercial sale is illegal in Michigan and most other states and inevitably damages natural populations. For rarer species, the loss of even a small number of individuals each year can lead to eventual disappearance of the local population. Captive-bred turtles of certain species are sometimes available from breeders or pet dealers, and are always preferable to wild-caught turtles. Check with the Michigan Department of Natural Resources Fisheries Division website for the latest regulations before taking any turtles from the wild.

Your Turtle Needs

Water (for swimming, drinking, feeding), warmth (a range of 75 to 85° F is good), a place to dry off (a basking spot), and a varied, balanced diet (explained below).

More Detailed Information


Glass aquaria (10 gallon size or larger) or large plastic storage boxes or cement-mixing tubs work well. Containers must be water-tight and escape proof. A ventilated top is useful to hold in warmth and humidity.


Image of red-eared slider (male)Most tap water is suitable for turtles. Depth depends on specimen size—usually 1 to 3 inches for small turtles; increased as they grow. A general "rule of thumb" is that the water can be about as deep as the length of the turtle's carapace (top shell). They should be able to swim freely, but not need to struggle to surface for air.

Keep it clean! Pet shops sell power filters useful for larger tanks. Small tanks can be cleaned by dumping and re-filling, at least 2 or 3 times per week.

Avoid sudden temperature changes.

Basking Spot and Lighting

Provide an accessible dry basking area. In small tanks, a smooth, sloping rock is fine. In larger tanks, a sloping ramp can be constructed of wood or plastic ("plexiglass" etc.). Tilting a tank with a small block of wood under one end is another way to provide a dry end with gradually deepening water. Position a 40 to 60 watt incandescent light over the basking area to give specimens a "hot spot" of about 80-85°F. Particularly in winter, a "full-spectrum" fluorescent light is helpful (e.g. Verilux®, Reptisun®, Vita-lite®, and others). Turtles kept outdoors benefit from direct sunlight, but provide a shady retreat, and guard against over-heating. Indoors or out, always protect your turtles from cats, other pets, and natural predators (birds, raccoons, etc.)!


An average temperature of about 78°F is fine for most temperate-zone turtles, but a temperature gradient is best (in other words, let the turtle choose its preferred temperature). The "hot spot" over the basking area should allow the turtle access to temperatures of 80-85°F , but the water temperature can be cooler (perhaps 72-75°F). Temperatures over 88°F for extended periods are stressful for our native species.

Winter: Releasing turtles well before winter is advised. If turtles are retained and kept active over winter, they must be kept at summertime temperatures and day length. Normal room temperature of 65-70°F is NOT suitable. It is possible to artificially hibernate captive turtles, but it is not advised except for research or captive breeding purposes. For more information on hibernating turtles, contact the author (hardingj@msu.edu or 517-353-7978).


Image of snapping turtle (juvenile)Your turtle needs the right foods for energy, protein, vitamins and minerals—just like you! Note that most native turtles will swallow food only when their heads are under water.

Foods for small aquatic turtles: "Natural" foods include whole, small or chopped fish, small earthworms, and small soft-bodied insects (Not flies or ants).  Many species also eat vegetable foods, such as leafy dark greens (Romaine, endive, leaf lettuce, etc.) and "pond weeds" (i.e., elodea, duckweed, etc.) Most commercial turtle foods are suitable as a "base" diet—for example products like Reptomin® and ZooMed® pellets are acceptable, as are some of the floating tropical fish pellets, such as Hikari Cichlid Gold®.

Do Not Feed: Hamburger or processed meats, raw poultry, head lettuce, or house flies. Fatty foods will harm the turtles, and raw chicken or other raw meats and flies can introduce harmful bacteria into the turtle tank—a threat both to the turtles and their keepers (discussed below). Feeding young turtles dog or cat food is not recommended—these are not properly balanced for most reptiles, and are messy in water.

Supplementary Nutrients: Turtles have a special need for certain nutrients, such as calcium and vitamins A and D3. Powdered or liquid vitamin and mineral supplements (available at pet and feed stores) can be mixed in food once or twice per week, and is particularly necessary whenever the diet offered turtles includes "muscle meats" (such as beef heart or pieces of fish) or other "incomplete" foods. A vitamin supplement must be well mixed into food, or it will be lost into the water.

Feeding Hints: Try to acclimate turtles to feed in a separate container other than their "home" tank. This greatly cuts down on cleaning and chance of contamination. It is also easier to keep track of how much each specimen is eating. Keep food pieces small. Many small turtles will learn to take bits of food from the end of a toothpick. If keeping more than one specimen, expect competition and fighting over food, and feed shy specimens separately. Baby turtles can be fed once per day, while for older juvenile and adult turtles, feeding 3 or 4 times per week may be sufficient. Older, less active turtles may become obese if over-fed.

Health and Growth

A healthy young turtle is alert, active, and grows quite rapidly—perhaps an inch or more per year. The shell should be firm (not "rock-hard", but should not feel soft or "squishy"), and should not thicken or "curl" at the edges. Growth rates slow as the turtle matures; thus a hatchling grows faster than a 3 or 4 year old turtle, and a mature turtle may hardly grow at all. The length of time needed to reach maturity varies between species, but is usually between 6 and 15 years. Check a good herpetology reference or field guide (noted below) to see how big your turtle should grow.

Turtles and "Salmonella"

Image of midland painted turtle (juvenile)The U.S. Food and Drug Administration has banned the sale of baby turtles under 4 inches in shell length because it was found that, under certain circumstances, turtles can carry bacteria, which can cause food-poisoning symptoms in humans. The problem occurred when parents bought baby turtles from pet shops for children who could not properly care for their pets. The turtles were often kept under unsanitary conditions prior to the sale, and then were poorly treated after purchase. This resulted in sickly turtles living in dirty water being handled by the children who often placed fingers (and sometimes turtles!) in their mouths. Thus, not surprisingly, some people got sick. The chances of catching any disease from a properly maintained captive-bred or wild-caught turtle is extremely small. (Pet dogs, cats, and birds potentially carry more risk for causing human illness than do turtles, and Salmonella is most often obtained from poorly stored food or raw eggs or poultry.) Of course, always wash your hands after handling turtles or any pet. Dirty turtle tanks should not be cleaned in a kitchen sink or near food preparation areas.

Health Problems

  • If your turtle seems inactive and loses its appetite, check the temperature (too cold? too hot?). See the section on "temperature" above. Check for proper diet. Is specimen getting enough of the right foods?
  • If your turtle develops a soft shell or the shell thickens or "curls" at the edges, check the diet. Is it getting enough vitamin A, vitamin D3, and calcium? (Most commercial pelleted turtle and fish foods are fortified with vitamins and minerals.) Does the turtle have access to a warm, dry basking spot?
  • If your turtle develops "puffy" looking eyes, it probably has a bacterial infection, often secondarily related to a vitamin A deficiency. Check the diet for vitamin A sources. Antibiotic eye ointments from a veterinarian may help.
  • If your turtle develops sores or lesions on its skin or shell, it may have "ulcerative disease." This is usually a bacterial disease caused by unsanitary living conditions, cool temperatures, poor nutrition, or infected injuries (or a combination of these). Drying the turtle for a few hours each day after applying a topical antibiotic like Betadine™ or Polysporin™ to lesions may help. Keeping the water slightly acidic by adding a few dried deciduous tree leaves collected in the fall may be beneficial for mild cases (maple leaves work well). Clean water frequently, and always allow the turtle access to a warm, dry spot. If in doubt, seek veterinary care for stubborn infections.
  • If your turtle has any of the previously mentioned symptoms and also appears weak and sits gasping with open mouth, it may have pneumonia. This is often caused by a poor diet and/or exposure to cool temperatures. Increase the temperature (80-85°F) and reduce stress. Offer food with extra vitamins if it will eat. A veterinarian trained in reptile care can diagnose the specific disease and advise on use of injectible antibiotics, which are usually necessary to effect a cure. Tropical fish medications from the pet shop usually don't work. Pneumonia is usually fatal if untreated and is especially difficult to treat and cure in very small turtles.

Note: It is easier to prevent diseases than it is to cure them. If turtles are not feeding well or do not adapt to captivity, release them where you found them before they become ill!

Releasing Captive Turtles

Image of common musk turtleAlthough we usually encourage returning turtles to the habitats from which they came, there are situations when captives should not be released. Diseases introduced by releasing sick captives have decimated natural turtle populations in some places. Thus, never release a turtle that shows any sign of illness, never release a native turtle that has been kept with non-native or exotic species, and never release a turtle species outside of its natural range!

For More Information

Check out our Critter Field Guide or obtain a good written field guide.

Recommended Books

Michigan Turtles and Lizards by J. H. Harding and J. A. Holman. 1990. Michigan State University Cooperative Extension Service, East Lansing, Bulletin E-2234.

Amphibians and Reptiles of the Great Lakes Region, Revised Edition by J.H. Harding. 2017, with David A. Mifsud, University of Michigan Press, Ann Arbor.

A Field Guide to Reptiles and Amphibians of Eastern and Central North America by R. Powell, R. Conant and J.T. Collins. 4th Ed. (2016) Houghton-Mifflin, Boston.

Image of red-eared slider (male)Acknowledgement

James Harding
MSU Museum
Michigan State University
East Lansing, MI 48824
(517) 353-7978