Detailed Introduction to the Classification and Common Varieties of Softshell Turtles

Introduction to the Classification and Common Varieties of Softshell Turtles

With the improvement of people's living standards and the growth of market demand at home and abroad, softshell turtles have gradually moved from hotels, restaurants and eateries into ordinary households. As a nutritious food, softshell turtles' dietary therapy and medicinal therapy functions can meet the needs of consumers at different levels. Market demand has stimulated production, and China's softshell turtle farming industry has developed rapidly, with the scale of farming continuously expanding and output increasing accordingly. Large-scale farming urgently needs a large number of softshell turtle hatchlings. Due to the rapid development, the breeding of seedlings, the classification, distribution and basic biological research of softshell turtles, as well as hatchling cultivation, species identification and disease prevention in farming production, cannot adapt to the needs of production development. Aquaculture operators and merchants in our province have purchased many softshell turtle hatchlings through different channels from abroad, Taiwan, China and other provinces in the mainland. Because these hatchlings come from different sources, their seed stock quality is unclear and it is hard to tell the genuine from the fake. Some farmers and aquaculture operators have paid a lot of "tuition fees," causing losses of varying degrees to production. Therefore, studying the classification and common varieties of softshell turtles and breeding superior softshell turtle varieties with good germplasm are urgent issues that must be solved for the sustainable development of the softshell turtle farming industry.

Classification of Softshell Turtles

The softshell turtle, commonly known as water fish or round fish, is a common farmed species in various parts of Jiangnan in China. According to scholars' research, the softshell turtle belongs in the animal kingdom to the class Reptilia and the family Trionychidae. The identified species of softshell turtles include 7 genera and 24 species: Chitra, Cyclanorbis, Cycloderma, Lissemys, Pelochelys, Sinaspideretes (a purely fossil genus) and Pelodiscus. China has 3 genera and 5 species: Pelochelys, Sinaspideretes and Pelodiscus.

The genus Pelochelys has two species: Pelochelys cantorii and the Taihu softshell turtle. Pelochelys cantorii is widely distributed in Indochina, Indonesia, the Philippines, the island of New Guinea and China's Zhejiang, Guangdong, Guangxi, Hainan, Yunnan and other places. The Taihu softshell turtle is distributed only in China's Jiangsu, Zhejiang and other places.

The genus Sinaspideretes is a fossil genus established by Chinese scholars in 1953 based on fossil specimens unearthed in Sichuan Province after identification. It has only one species, namely Sinaspideretes wimani.

The genus Pelodiscus is widely distributed in Asia, Africa and North America, with a total of 16 species. China produces two species, namely Pelodiscus sinensis and the wattle-necked softshell turtle (Palea steindachneri). In China, softshell turtles are distributed in all provinces, municipalities and autonomous regions except Ningxia, Gansu, Qinghai, ** and Tibet. The wattle-necked softshell turtle is distributed in southern provinces and regions such as Guangdong, Guangxi, Hainan, Yunnan and Guizhou.

Regarding the classification of softshell turtles, some scholars in mainland China and the Taiwan scholar Mr. Yu Tingji once advocated calling the softshell turtles produced in southern China (the Yangtze River basin) and Taiwan province "Chinese softshell turtle," those produced in the north "northern softshell turtle," and those produced in Yunnan, Guangdong, Hainan and other places "round softshell turtle." However, the morphology of the above three kinds of softshell turtles is extremely similar. At present, Mr. Yu's view has not been accepted by the vast majority of aquaculture scholars. Therefore, before the classification and scientific names of the above three kinds of softshell turtles have been properly sorted out and unified academically, it is still appropriate to collectively call them the Chinese softshell turtle.

Common Softshell Turtle Species

At present, there are many sources of softshell turtles. In addition to the softshell turtle varieties native to mainland China, Taiwan, China as well as Thailand, Vietnam, Bangladesh, Malaysia and the United States all produce them. The following are commonly seen domestically:

1. Chinese softshell turtle

The Chinese softshell turtle resembles a tortoise, with a nearly round body that is relatively flat and thin. Its body is dark green, without black spots or tubercles, and its belly is grayish white; some softshell turtles are yellow, and there are no warts on the neck. Offspring bred from wild Chinese softshell turtle parents from the rivers, lakes and reservoirs of the Yangtze River system and the Pearl River system have better germplasm, grow quickly, have relatively few diseases, and also achieve higher population yields and economic benefits. The hatchlings bred by the Desheng Power Plant Softshell Turtle Farm in Shunde City and the Daming Softshell Turtle Farm in Daliang District are Chinese softshell turtles.

2. Thai softshell turtle

Many Thai softshell turtle hatchlings enter China, with 40-50 million per year. The condition of their parents is unknown, so it is appropriate to temporarily call them Thai softshell turtles. In production, some Thai softshell turtles are diseased and have a relatively high mortality rate. Although their price is relatively cheap, the negative effects caused by disease and death during farming are well known, and buyers of hatchlings must have a clear understanding of this.

3. Taiwan softshell turtle

According to scholars' research, Taiwan merchants, taking advantage of the early-maturing characteristics of Taiwan softshell turtles and mature technology, use the time difference to carry out large-scale artificial breeding and high-temperature acceleration, and input large quantities of softshell turtle hatchlings into the mainland for sale. Their growth situation is similar to that of Thai softshell turtles.

4. Sand softshell turtle

The sand softshell turtle is produced in the waters around Hunan. Its back is dark green, relatively black, with a raised back, and its belly is yellow. Preliminary research suggests it may be a hybrid variety, or it may be a variant of the Chinese softshell turtle. Its individuals are small, grow slowly, and commercial softshell turtles have poor taste; it is prone to disease during farming and is not suitable as a farming subject.

Several Suggestions

1. Farmers should choose the Chinese softshell turtle as the farming variety

Many years of production practice have shown that the Chinese softshell turtle is outstanding among China's farmed softshell turtle varieties. Its germplasm, growth speed, disease resistance, taste and market price are all relatively good, and it is quite popular with consumers. Farmers should give first priority to farming the Chinese softshell turtle.

2. Farms and aquaculture operators with the conditions should establish their own Chinese softshell turtle farming bases. Farms should purchase Chinese softshell turtle parents from the Yangtze River system and breed and cultivate seedlings themselves for farming. If there is a surplus beyond their own needs, they may also sell Chinese softshell turtles to other farms or farmers.

3. Carefully distinguish, identify and purchase softshell turtle hatchlings

When purchasing hatchlings, if farmers are not confident, they should consult experienced aquaculture operators or technicians to carefully distinguish and identify them, and try not to purchase hatchlings that are not Chinese softshell turtles. Relevant state departments and scientific research institutions should carefully study the parent germplasm and classification of softshell turtles, formulate practical classification and identification methods, and guide production. Farmers should also study diligently, participate in training, combine theory with practice, continuously improve their own quality, quickly master classification methods, and be able to purchase Chinese softshell turtle hatchlings with pure germplasm when buying hatchlings, so as to pay less "tuition fees." Grassroots aquatic technology extension departments should also strengthen services to promote the healthy development of the softshell turtle farming industry.