Iverson’s Turtle

1 Overview

Iverson’s Turtle, also called the Fujian stone turtle, is a China-endemic species. So far found only in Fujian (Nanping and Jianyang) and Guizhou (central, near Guiyang), it is very scarce and is listed in the ‘Catalogue of Terrestrial Wildlife with Important Economic, Scientific, or Conservation Value’ issued by China’s State Forestry Administration on August 1, 2000.

Many farms now breed it, where it can be bought. Its appearance resembles the yellow pond turtle, which is widely distributed in China with three main lines: the Vietnamese stone turtle, the large green-head turtle (Iverson’s), and the small green-head turtle (Hunan stone turtle). Keepers generally call the Vietnamese one the southern turtle and the green-head ones the northern turtle.

Chinese Name: Iverson’s Turtle

Alias: Fujian stone turtle, green-head turtle

Latin Name: Mauremys iversoni

Classification: Chordata, Reptilia, Testudines, Geoemydidae, Mauremys, Mauremys iversoni

Distribution: China-endemic, found only in Fujian (Nanping, Jianyang) and Guizhou (central, near Guiyang). Habitat: aquatic. Suitable water temperature about 22°C; enters hibernation around 12°C. Temperament gentle, not fearful of people. Diet: omnivorous in captivity, favoring meat, fish, and shrimp, with little plant. Adult size: carapace 189 mm (male), 193 mm (female). Reproduction: oviparous, but breeding data are not yet reported. Difficulty: average. Hibernates. Price: 500–2000 yuan by size; hatchlings about 100 yuan.

2 Physical Characteristics

Carapace length 189 mm (male), 193 mm (female). The carapace has three ridges with an obvious central keel. The carapace and plastron meet by bony suture; the plastron is shorter than the carapace. The gular scute projects, its front center slightly concave; the anal scute has a deep posterior notch. The pectoral and abdominal scute sutures are longest and nearly equal; the humeral suture is shortest. Toes are fully webbed.

There are seven neural plates: the first is quadrilateral; the 2nd–4th are hexagonal with the short side behind; the 5th and 6th are pentagonal, the 7th hexagonal with the short side in front. The internal plate is medium-sized; the humero-pectoral suture crosses the rear one-quarter.

3 Husbandry

It inhabits the buffer zones of fast hill streams or backwaters. Omnivorous, favoring fish, shrimp, snails, and insects, occasionally bananas. It lays eggs from May to September, 2–3 times a year, 1–5 eggs each, about 13 g per egg. Hatchlings have olive-green heads, hence ‘green-head turtlelets’.

Selecting breeders: choose individuals over 900 g, complete and defect-free, bright-colored, lively, and healthy. Males should be flat-long with strong limbs and a thick tail. Because farmed turtles grow fast with even annuli, age is hard to judge — always ask the actual farmed years, since most mature reproductively at four years; a heated-farmed turtle may reach 900 g in 2–3 years but cannot lay. Buy from two farms and swap males to avoid inbreeding.

Care: most of its range has a tropical monsoon climate — hot, rainy, with clear dry/wet seasons; annual mean 23–27°C. This suits growth, so wild growth is fast and individuals large. Control temperature: hibernate below 15°C; water above 35°C harms it, and above 38°C for over 2 hours is fatal. Watch heating in winter.

4 Habitat and Distribution

Distributed in Fujian and Guizhou, China, it inhabits mountain streams at about 500 m elevation and slow ponds. Its species validity is debated; the journal Nature reported that U.S. scholar James Parham and Chinese scholar Shi Haitao confirmed by experiment that Iverson’s Turtle is a hybrid of the yellow pond turtle (Mauremys mutica) and the three-lined box turtle (Cuora trifasciata).

Wild habitat: hill-stream buffer zones or backwaters, occasionally rice paddies. Omnivorous, favoring fish, shrimp, snails, insects, occasionally bananas; hatchlings olive-green headed. In mainland China it is found in Fujian and Guizhou; the type locality is near Nanping, Fujian.

Captive environment: most adults are kept in turtle-fish polyculture. Ponds can be larger, 667–2668 m² each. The site should be open, sunny, with ample unpolluted water. Ponds are rectangular, split into water (3/4) and beach (1/4) at a 25–30° slope; water 2–2.5 m deep, kept at 1.5 m. Separate inflow/outflow; beach covered with 20–30 cm fine sand; a 1 m bare strip around with 60 cm smooth walls to prevent escape; platforms at the waterline as feeding stations; barriers at in/outlets.

5 Feeding

An aquatic turtle from hill streams and rivers, it spends most time foraging in water and sometimes in shrubbery. Omnivorous with a broad diet: wild insects, arthropods, small fish, shrimp, snails, clams, wheat, rice, and fruit.

Food choices: wild ones eat aquatic insects, fish, amphibians, mollusks, aquatic plants, annelids, shrimp, etc. Match the natural diet and respect nature, using pellets as supplement.

Portions: juveniles grow fast and need frequent feeding (small, frequent meals suit their short gut); ensure exercise to maintain shape in small tanks. Adults grow very slowly with fixed bone — lengthen feeding interval but balance exercise and food; bigger environment, more exercise, more food, shorter interval, and vice versa.

Seasonal: spring temperatures swing fast and the gut is sluggish after hibernation — feed little, easily digested food, longer intervals. Summer: more food, shorter intervals. Autumn: less food, finer food for hibernation. Indoors temperatures are stable, but below 16°C reduce or stop feeding; spring and autumn are peak seasons for gastroenteritis.