Chinese softshell turtle

Appearance

Females of the Chinese softshell turtle can reach up to 33 cm in carapace length, while the smaller males reach 27 cm, but however have longer tails than the females. Maturity is reached at a carapace length of 18–19 cm. It has webbed feet for swimming. They are called "softshell" because their carapace lacks horny scutes. The carapace is leathery and pliable, particularly at the sides. The central part of the carapace has a layer of solid bone beneath it, as in other turtles, but this is absent at the outer edges. The light and flexible shell of these turtles allows them to move more easily in open water, or in muddy lake bottoms.

The carapace of these turtles is olive in color and may have dark blotches. The plastron is orange-red, and may also have large dark blotches. The limbs and head are olive dorsally with the forelimbs lighter and the hind-limbs orange-red ventrally. There are dark flecks on the head and dark lines that radiate from the eyes. The throat is mottled and there may be small, dark bars on the lips. A pair of dark blotches is found in front of the tail as well as a black band on the posterior side of each thigh.

Naming

Populations native to Northeast China, Russia, Korea and Japan were formerly included in this species, but are now regarded as separate as the northern Chinese softshell turtle. Furthermore, localized populations in Guangxi and Hunan, as well as Vietnam, are recognized as the lesser Chinese softshell turtle and Hunan softshell turtle.

Distribution

The Chinese softshell turtle is native to Taiwan and China, where it is found in Anhui, Fujian, Gansu, Guangdong, Guangxi, Guizhou, Hebei, Henan, Hong Kong, Hubei, Hunan, Inner Mongolia, Jiangsu, Jiangxi, Shaanxi, Shandong, Shanxi, Sichuan, Yunnan and Zhejiang Provinces.

Populations native to Northeast China, Russia, Korea and Japan were formerly included in this species, but are now regarded as separate as the Amur softshell turtle. Populations in Vietnam and Hainan Island are now recognized as the spotted softshell turtle. Furthermore, localized populations in Guangxi, Hunan, and Anhui are recognized as the lesser Chinese softshell turtle, Hunan softshell turtle, and Huangshan softshell turtle.

It is difficult to determine its exact native range of the Chinese softshell turtle due to the long tradition of use as a food and herbal medicinal, and subsequent spread by migrating people. Outside their native China, escapees have been recorded in a wide range of countries and some of these have becomes established as introduced populations. Among the non-native locations in Asia are the Bonin Islands, Honshu, Kyushu, Ryukyu Archipelago and Shikoku in Japan; South Korea; Laos; Vietnam; Thailand; Singapore; Bohol, Cebu, Leyte, Luzon, Mindanao, Mindoro and Panay in the Philippines; East and Peninsular Malaysia; Kalimantan, Sumatra and West Timor in Indonesia; East Timor; and Iran. Outside Asia, locations include Pará in Brazil; Spain; and Guam, Northern Mariana Islands and Oahu in the United States.

Status

The Chinese softshell turtle is a vulnerable species, threatened by disease, habitat loss, and collection for food such as turtle soup. Chinese soft-shell turtles were the first turtle species to undergo a large-scale outbreak of bacterial softshell disease, resulting in slower growth and increased fatality. This lead not only to a decline in "P. sinensis", but caused severe economic losses to the turtle culture industry. Additionally, millions are now farmed, especially in China, to support the food industry, and it is the world's most economically important turtle.

Behavior

These turtles reach sexual maturity sometime between 4 and 6 years of age. They mate at the surface or under water. A male will hold the female's carapace with its forelimbs and may bite at her head, neck, and limbs. Females may retain sperm for almost a year after copulation.

The females lay 8–30 eggs in a clutch and may lay from 2 to 5 clutches each year. The eggs are laid in a nest that is about 76–102 mm across at the entrance. Eggs are spherical and average about 20 mm in diameter. After an incubation period of about 60 days, which may be longer or shorter depending upon temperature, the eggs hatch. Average hatchling carapace length is about 25 mm and width is also about 25 mm. Sex of the hatchlings is not determined by incubation temperature.

Habitat

Chinese softshell turtles live in fresh and brackish water. In China these turtles are found in rivers, lakes, ponds, canals and creeks with slow currents, and in Hawaii they can be found in marshes and drainage ditches.

Food

These turtles are predominantly carnivorous and the remains of fish, crustaceans, mollusks, insects, and seeds of marsh plants have been found in their stomachs.