A Detailed Guide to Soft-Shelled Turtle Farming Techniques and Management Methods

The soft-shelled turtle, also known as the Chinese softshell turtle (Pelodiscus sinensis), is commonly called soft-shelled turtle, water turtle, or wangba. In China, it is distributed in all provinces (autonomous regions) except Ningxia, **, and Tibet, and it is also found in Vietnam, Korea, Japan, and other countries. This species is extensively farmed in China, mainly through industrial farming and pond farming. In earlier years, driven by high profits, the farming area grew out of control, and large quantities of imported soft-shelled turtles flooded the domestic market, causing the price of commercial soft-shelled turtles to drop sharply and dealing a heavy blow to the soft-shelled turtle farming industry. At present, the development of the soft-shelled turtle farming industry can only be maintained by reducing production costs and increasing the survival rate. It is recommended that regions without temperature control conditions minimize their farming scale or reduce stocking density (1000-1500 per mu) and raise the water depth to 1.5 m to 1.8 m (for extensive farming).

Overview of the Soft-Shelled Turtle

The soft-shelled turtle is a general term for soft-shelled aquatic turtles of the family Trionychidae, order Testudines. Also known as: softshell turtle, water turtle, wangba, there are more than 20 species. In China, the main existing species are the Chinese softshell turtle (Pelodiscus sinensis), the Asian giant softshell turtle (Pelochelys cantorii), the Yangtze giant softshell turtle (Rafetus swinhoei), and the Chinese giant softshell turtle (Pelochelys maculatus), among which the Chinese softshell turtle is the most common. It is an oviparous amphibious reptile. The soft-shelled turtle is delicious and highly nutritious. Because it has many tonic and medicinal effects, it can clear heat and nourish yin, calm the liver and extinguish wind, soften hardness and dissipate nodules, and is effective for liver cirrhosis, hepatosplenomegaly, and infantile convulsions. Therefore, it is not only a delicious dish on the dining table and a high-quality ingredient for banquets, but can also be used as an important traditional Chinese medicine material.

1. Living environment: Soft-shelled turtles mainly live in lakes, ponds, reservoirs, deltas, and slow-flowing rivers. The soft-shelled turtle is a poikilothermic animal, amphibious between water and land, and breathes with its lungs, so there must be a sufficient area of land and sand beach around or in the center of the turtle pond for it to carry out activities on land. The living habits of the soft-shelled turtle can be summarized as "three likes and three fears," namely: likes quiet and fears disturbance, likes sunlight and fears wind, likes cleanliness and fears dirt. The soft-shelled turtle is sensitive to sounds in its surrounding environment. As long as there is the slightest movement nearby, the soft-shelled turtle can quickly dive into the mud at the bottom of the water, so the environment of a turtle farm or turtle pond must be kept quiet. If the soft-shelled turtle is frequently startled, it is very unfavorable for its growth and reproduction.

2. Living habits: These can be simply summarized as "three likes and three fears," namely: likes cleanliness and fears dirt, likes sunlight and fears wind, likes quiet and fears disturbance. In the natural environment, soft-shelled turtles like to inhabit waters such as rivers, lakes, reservoirs, and ponds with clean water quality. On calm and sunny days, they often lie on the sunny shore basking in the sun (commonly known as sun-drying the back), using ultraviolet rays in sunlight to kill pathogenic bacteria on the body surface, promote the healing of injured body surfaces, and raise body temperature through basking to promote food digestion. The soft-shelled turtle is very timid and is very sensitive to sounds and the movement of objects in its surrounding environment. At the slightest disturbance, it dives to the bottom of the water. The soft-shelled turtle is naturally fierce and combative, and the phenomenon of the strong bullying the weak among groups is very common. When food is scarce, they will eat their own kind. During the growth period, they mainly breathe with their lungs. When the water temperature is below 15°C, the soft-shelled turtle dives into the mud at the bottom of the pond to begin hibernation, relying on auxiliary respiratory organs such as gill-like tissues in the throat area for respiration. In the Hangjiahu area, the hibernation period of the soft-shelled turtle is from mid-November each year to around mid-April of the following year.

3. Soft-shelled turtle food: The softshell turtle is an aquatic omnivorous animal and prefers animal-based bait. Juvenile turtles feed on aquatic insects, aquatic earthworms, tadpoles, small shrimp, etc. Adult turtles feed on mollusks such as field snails and clams, fish, shrimp, and animal carcasses (because they cannot catch fish), and also eat plant-based feed such as green fodder vegetables, melons and fruits, and miscellaneous grains (wheat, corn, soybeans, rice, etc.).

4. Nutritional value

① The soft-shelled turtle, also called tuanyu or bie. Its meat has the delicious flavors of 5 kinds of meat: chicken, deer, beef, mutton, and pork, so it has long been known by the laudatory name "meat of five flavors." In its body, no carcinogenic factors can be found at all. The soft-shelled turtle has therefore greatly increased in value. The soft-shelled turtle is rich in nutrients such as animal glue, keratin, copper, and vitamin D, can enhance the body's disease resistance and regulate the human endocrine function, and is also a tonic delicacy for improving the quality of breast milk and enhancing infants' immunity and intelligence.

② The ventral plate of the soft-shelled turtle is called "turtle plastron," a precious traditional Chinese medicine with the effect of nourishing yin and reducing fire. It is used to treat conditions such as dizziness, vertigo, deficiency heat, and night sweats. It also has a good therapeutic effect on stubborn headaches left by head trauma (such as neonatal cephalohematoma, etc.). Turtle plastron glue is a macromolecular collagen protein, contains various amino acids needed by the skin, and has the effect of nourishing the face and protecting the skin, and promoting beauty and fitness. Of course, turtle plastron is a traditional Chinese medicine, and whether to use it should be decided by a doctor according to the specific situation.

③ The neck of the soft-shelled turtle can treat rectal prolapse. Take the whole neck, dry-roast it over a slow fire, crush it, mix it evenly with hot vinegar, with the degree of being moist and permeated with vinegar, wrap it tightly in field gauze, sit on it and fumigate with the vapor, and generally 3-5 times is enough for recovery. Although the soft-shelled turtle has a very good effect on postpartum weakness and reduced energy. However, pregnant women and those with postpartum constipation should not eat it or should eat it in moderation.

Construction of Soft-Shelled Turtle Farming Ponds

1. Construction of industrial temperature-controlled soft-shelled turtle farming ponds

In order to break the habit of long-term hibernation required for wild farming of soft-shelled turtles, seedling breeding can adopt industrial artificial temperature-controlled farming. At present, there are many models of artificially temperature-controlled soft-shelled turtle ponds in China, but to achieve the good results of both saving money and healthy farming, the following basic requirements must be met.

① Good insulation performance: Insulation is one of the main conditions for a greenhouse to ensure farming output. Whether using electric heating, geothermal heat, factory waste heat, or boiler heating, all are for the purpose of adjusting the water temperature to the optimum range most favorable for the growth of soft-shelled turtles. Some places do not pay attention to insulation performance, resulting in excessive day-night temperature differences indoors or excessive temperature differences between rooms, which affects growth and even causes disease, so insulation should be the first consideration in design.

② Good lighting: Lighting in soft-shelled turtle ponds is not only to use light energy to increase indoor temperature, but also to regulate water quality through light sources, thereby reducing disease and increasing the survival rate. Practice has proved that using the same method in 2 greenhouses, one insulated but opaque and the other both insulated and light-transmitting, the growth speed is about the same, but in terms of disease, the light-transmitting one has a higher survival rate than the opaque one. This not only reduces farming costs but also improves the quality of the soft-shelled turtles. In particular, a reasonably designed light-transmitting greenhouse costs less than half as much to invest in as a completely closed greenhouse. Moreover, it is convenient to manage and easy to operate.

③ Convenient water filling and drainage: Water used in greenhouses is often only changed when the water quality has deteriorated to the point where it must be replaced, and at ordinary times it is kept as stable as possible. When changing water, a fast speed and short time are required. Therefore, both the amount of water filled and the amount of water drained are very large. So a smooth water filling and drainage system should be guaranteed at all times. In some places, the soft-shelled turtle ponds are below ground level, and mechanical pumping is needed for drainage, so the guarantee of power supply should be considered in the design. In order to meet the need for water filling at any time, it is best to have a temperature-regulating storage pond that guarantees a full-load water supply.

④ Reasonable number of levels: In industrial soft-shelled turtle farming, ponds are mostly built with reinforced concrete structures, so the number of levels must be reasonable in design and construction. In particular, any industry may inevitably experience rise and decline and the possibility of switching production in the future. Even if the industry does not change, the structure will also be improved with development. Moreover, the structure of soft-shelled turtle ponds is difficult to use for other purposes, and it is a terminal development project for one-time use. Therefore, when designing the number of levels, it is necessary to consider not only the lighting angle, temperature regulation, and reasonable operation, but also long-term viability and variability. Some places, in order to improve land utilization, build three or four levels of soft-shelled turtle ponds and make the greenhouses tall and large, which is not only inconvenient for operation and management, but also makes it difficult to regulate the water temperature between the upper and lower levels, and even more difficult to change their use. Therefore, it is best not to exceed 2 levels.

According to the above requirements, single-layer double-row soft-shelled turtle ponds are ideal. The advantages of this kind of soft-shelled turtle pond are good light transmission, low cost, fewer farming diseases, high survival rate, and it can be used all year round, and once production is switched, it is also easy to demolish.

2. Construction of finishing ponds for adult soft-shelled turtles

Finishing ponds for adult soft-shelled turtles are usually made of cement structure, with a single pond area of 100-200 sq m, rectangular, pond depth 1.2 m, water depth 1 m. The pond slope is rectangular, with an anti-escape eave at the top of the slope, a sand-blocking wall at the bottom of the pond, complete water filling and drainage facilities, a basking platform in the pond, and a feed platform at one end of the pond edge.