Mauremys reevesii

Aquaterrarium / large aquarium with a filtered water area and a heated dry basking area under UVB

Minimum dimensions for a single adult (aim for ≈100-150 L of water); bigger is always better. Allow roughly +30-40% of space and water volume per additional individual. A good climber: provide a rim or lid preventing escape. Separate males or monitor them when kept together.

A semi-aquatic species: the humidity of the air above the water is naturally high and not very critical. The priority is good-quality WATER and a dry basking area allowing complete drying of the plastron and carapace, to prevent shell rot.

Avoid fine or small-sized gravel, which is accidentally ingested (risk of digestive obstruction). A bare-bottom tank greatly facilitates maintenance and control of water quality. An accessible dry basking area (cork, ramp, platform) that is heated and lit with UVB is essential.

Essential: a UVB 5.0 (≈5%) to 6% tube or lamp installed above the basking area, at the distance recommended by the manufacturer, and replaced every 6-12 months. Essential for vitamin D3 synthesis, calcium absorption and shell health (prevention of MBD).

A filtered aquatic environment is MANDATORY: a powerful filter (flow rate ≈2-3× the volume per hour), regular partial water changes and dechlorinated water. Recommended depth ≈15-30 cm allowing it to swim while easily reaching the surface (mediocre swimmer); provide plenty of ledges and supports. Clean water is the primary prevention of aural abscesses and shell rot.

East Asia: central and eastern China, the Korean Peninsula, Japan and Taiwan. Inhabits shallow, slow-flowing freshwater environments: marshes, ponds, pools, rice paddies and ditches with a soft bottom. Listed as ENDANGERED (EN) by the IUCN, heavily collected in the wild and massively farmed in Asian farms. Non-venomous and not listed under CITES, but threatened in the wild: it is imperative to favour captive-bred animals and refuse wild-caught specimens.

Omnivore with a carnivorous tendency in juveniles, becoming more vegetarian with age — Insects, earthworms, freshwater snails and shrimp, small fish (in moderation), specialised pellets for aquatic turtles; on the plant side: aquatic plants (elodea, duckweed, water lettuce) and some fruit/vegetables

Very opportunistic and voracious. Feed juveniles daily, adults every 2-3 days in reasonable amounts to avoid obesity. Supplement calcium (cuttlebone available). Limit fatty foods (oily fish, red meats, liver). Offer the food in the water.

Clutch 4–10 eggs/young. 1 to 3 clutches per year. Incubation of about 55-80 days at 26-30°C. Temperature-dependent sex determination (TSD). Provide a terrestrial laying site (moist, loose sand/soil substrate) for gravid females. Sexual maturity around 4-6 years. Beware of possible hybridisation with other Mauremys in captivity.

• Metabolic bone disease (MBD) and deformation/softening of the shell due to calcium deficiency or lack of UVB
• Shell rot (bacterial or fungal ulcerative dermatitis) linked to poor water quality or insufficient drying
• Respiratory infections (pneumonia) due to water/air that is too cold or to draughts
• Aural abscesses (lateral swelling of the head), often associated with dirty water and/or vitamin A deficiency
• Hypovitaminosis A (eyelid oedema, swollen eyes) and digestive parasitoses