The Chinese pond turtle (Mauremys reevesii), also called the Reeves' turtle or the Chinese three-keeled pond turtle, is one of the most popular pet turtles in Asia and increasingly in Europe and North America. It is medium-sized, hardy, interactive, and has a unique trait that surprises new keepers: males turn almost completely black as they mature.
This guide covers everything you need to know to keep a Chinese pond turtle healthy — tank setup, diet, male blackening, and the one care requirement that separates it from hardier species like the red-eared slider.
Species Overview
Chinese pond turtles are native to East Asia — China, Korea, Japan, and Taiwan. They live in slow-moving rivers, ponds, marshes, and rice paddies with soft bottoms and plenty of aquatic vegetation.
| Attribute | Detail |
|---|---|
| Scientific name | Mauremys reevesii |
| Common names | Chinese pond turtle, Reeves' turtle, Chinese three-keeled pond turtle |
| Adult size | Males 5–6 in; females 7–8 in |
| Lifespan | 20–30 years (up to 40) |
| Diet | Omnivorous (more plant matter as adults) |
| Minimum tank | 40 gallons |
| Recommended tank | 55-gallon or larger |
| Water temperature | 24–28°C (75–82°F) |
| Basking temperature | 30–33°C (86–91°F) |
| UVB requirement | Essential; 5.0 bulb, 10–12 hours daily |
The species is named for the three longitudinal keels (ridges) that run down the carapace of juveniles and young adults. In older turtles, these keels often smooth out.
Tank Size and Setup
Minimum tank size: 40 gallons for a single adult. Recommended: a 55-gallon tank or larger, especially for females, which grow bigger than males.
Water depth: 10 to 16 inches for adults. Chinese pond turtles are strong swimmers and enjoy deeper water than musk turtles, but they still need easy access to a dry basking platform.
Filter: this is the single most important piece of equipment for this species. Chinese pond turtles are more sensitive to water quality than sliders, and poor filtration quickly leads to shell rot. Choose a canister filter rated for at least 2x the tank volume — for a 55-gallon tank, that means a filter rated for 110 gallons or more. See our filter guide.
Basking platform: stable, non-slip, large enough for the turtle to dry off completely. Positioned under both a heat lamp and a UVB bulb. See our basking platform guide.
Substrate: bare-bottom is easiest to clean, but if you want substrate, use sand or large river stones. Avoid small gravel — Chinese pond turtles will eat it and risk impaction.
Plants and decor: this species appreciates cover. Use tough plants like Anubias and Java fern, and provide driftwood or cork bark for hiding. See our aquascaping guide.
Water Quality and Temperature
Water temperature: 24 to 28°C (75 to 82°F). Use a guarded submersible heater sized at 3 to 5 watts per gallon, and always verify with a separate thermometer. See our water temperature guide.
Water quality: this is where Chinese pond turtles differ from hardier species. They are more sensitive to ammonia, nitrite, and nitrate than sliders or musk turtles. Poor water quality quickly leads to shell rot and skin infections.
To keep water quality high:
- Use a filter rated for 2x the tank volume
- Change 25–50% of the water weekly
- Test ammonia and nitrite weekly — both should read zero
- Remove uneaten food within 15 minutes
- Rinse filter media in tank water, never tap water
UVB lighting: essential. Use a 5.0 UVB bulb mounted 20 to 30 cm above the basking area. Run it 10 to 12 hours daily. Replace every 6 to 9 months. See our UVB guide.
Diet and Feeding
Chinese pond turtles are omnivores. Juveniles are more carnivorous, while adults shift toward a plant-heavy diet.
Staple foods:
- Commercial turtle pellets (a base, not the entire diet)
- Dark leafy greens: romaine, dandelion, kale, collard greens
- Aquatic plants: duckweed, water lettuce, Elodea
- Earthworms, mealworms, bloodworms
- Shrimp and small snails (shell-on for calcium)
- Feeder fish (offer infrequently — parasite risk)
Feeding schedule: juveniles daily, adults every 1 to 2 days. Feed an amount roughly the size of the turtle's head per session. Remove uneaten food within 15 minutes.
Supplements: calcium (cuttlebone or calcium powder) two to three times per week, and a multivitamin once weekly. See our complete diet guide.
Why Males Turn Black
One of the most striking features of this species is that males undergo melanism as they mature. Around 4 to 6 years of age, a male's shell, skin, eyes, and even his claws gradually darken until he is almost completely black.
This is not a disease or a sign of illness. It is a normal, genetically programmed process linked to sexual maturity. In the wild, melanistic males are thought to have an advantage in courtship — the all-black coloration is a strong visual signal to females.
Females do not turn black. They retain their brown, olive, or yellowish coloration throughout life, with three distinct keels on the carapace. This makes it easy to sex adults: if a mature turtle is completely black, it is male. If it retains a lighter, keeled appearance, it is female.
Note: occasionally a female will darken slightly with age, but she will never become fully black. True melanism is a male-only trait.
Common Health Issues
Chinese pond turtles are hardy but still susceptible to the same husbandry-related problems as other aquatic turtles.
- Shell rot. Caused by dirty water. This is the most common health problem in this species because of their sensitivity to water quality. Symptoms are white or grey patches on the shell. See our shell rot guide.
- Respiratory infection. Caused by temperature drops. Symptoms are open-mouth breathing, nasal discharge, and floating tilted. See our respiratory infection guide.
- Metabolic bone disease. Caused by inadequate UVB or calcium deficiency. See our MBD guide.
- Eye infection. Often caused by vitamin A deficiency or dirty water. See our eye infection guide.
- Aggression between males. Male Chinese pond turtles can be aggressive toward each other, especially during breeding season. Do not house two males together unless the tank is very large.
Frequently Asked Questions
How big do Chinese pond turtles get?
Chinese pond turtles (Mauremys reevesii) reach 5 to 8 inches (13 to 20 cm) as adults. Males typically stay smaller at 5 to 6 inches, while females grow to 7 to 8 inches. This makes them a medium-sized species suitable for a 40 to 55-gallon tank.
Why does my Chinese pond turtle turn black?
Male Chinese pond turtles undergo a process called melanism as they mature. Around 4 to 6 years of age, males gradually turn almost completely black — including the shell, skin, and eyes. This is normal and is linked to sexual maturity and breeding condition. Females do not turn black.
What do Chinese pond turtles eat?
Chinese pond turtles are omnivores. A balanced diet includes commercial turtle pellets, leafy greens (romaine, dandelion, kale), aquatic plants, and protein sources like earthworms, shrimp, and feeder fish. Juveniles need more protein; adults shift toward more plant matter.
Are Chinese pond turtles good for beginners?
Yes, with one caveat: they are more sensitive to water quality than red-eared sliders or musk turtles. They are hardy, interactive, and long-lived, but they need strong filtration and consistent water changes. If you can commit to that, they are an excellent beginner species.
How long do Chinese pond turtles live?
With proper care, Chinese pond turtles commonly live 20 to 30 years in captivity, and some reach 40 years. This is a long-term commitment that should be planned for before acquiring one.
Final Thoughts
The Chinese pond turtle is a rewarding species for keepers who are willing to invest in proper filtration. It is medium-sized, hardy, and full of personality. The dramatic blackening of mature males is one of the most striking transformations in the turtle world.
If you can provide clean water, stable temperatures, and a proper basking area, a Chinese pond turtle will be a fascinating companion for 20 to 30 years.
For more on species care, see our beginner's guide and our red-eared slider guide.
Sources & References
- Ernst, C. H., & Lovich, J. E. (2009). Turtles of the United States and Canada (2nd ed.). Johns Hopkins University Press.
- Bonin, F., Devaux, B., & Dupré, A. (2006). Turtles of the World. Johns Hopkins University Press.
- Merck Veterinary Manual. Management and Husbandry of Reptiles. Retrieved 2026.
- Association of Reptilian and Amphibian Veterinarians (ARAV). Care sheets for common pet chelonians. Retrieved 2026.
- van Dijk, P. P., et al. (2014). Mauremys reevesii. The IUCN Red List of Threatened Species. Retrieved 2026.
