Artificial domestication breeding of wild mountain wild fish

Palea steindachneri is a nationally protected second-class animal, and due to the continuous decline in wild populations, it is essential to domesticate and breed these turtles in captivity. This study focuses on the domestication and breeding techniques of mountain wild turtles, aiming to provide scientific support for their conservation and large-scale reproduction. **Materials and Methods** **1.1 Domestication** **1.1.1 Domesticated Ponds** The domestication ponds are designed with an area ranging from 2,000 to 3,333 square meters, with a water depth of 1.5 meters. Aquatic plants are planted in shallow areas near the pond edges to create a natural environment. The location is chosen to be quiet, with T-shaped escape walls around the perimeter and the pond facing southward toward a river. A 20-square-meter spawning area is constructed on a sandfield under rainproof shaded structures. A wooden drying platform and feeding table are built in the middle and eastern parts of the pond, separated by 2 meters. Water hyacinth (Eichhornia crassipes) covers approximately one-fifth of the water surface to enhance the ecological balance. **1.1.2 Source of Mountain Rui** Wild mountain turtles weighing between 1 to 2 kg were selected from local markets or captured from the mountains. They were required to be healthy, free from injuries or diseases, with bright skin, thick shells, and active behavior. **1.1.3 Feeding and Taming** Commercially available complete feed was used, supplemented with fresh fish, snails, and shrimp. Animal feed was soaked in 5% saltwater for 15–20 minutes before being washed with clean water. Feeding was done using a multi-point method, placing food 5 cm away from the water’s edge to attract the turtles. Feeding started at 6:00 PM daily, and residual food was removed within the first two days. By day eight, the turtles began to approach the feeding platform. After 15 days, the domestication process was largely complete, and the turtles adapted well to feeding on the platform. Daily feeding was then conducted, with 3–5% of their body weight given in the morning and evening, gradually increasing to full feed while adding some green vegetation. **1.1.4 Daily Management and Disease Prevention** Following the "Four Sets" principle, regular observations and detailed records were kept. Freshwater was regularly added, and leftover food was promptly removed to maintain water quality. Disinfectants such as dibromohydantoin, iodine compounds, or lime milk were applied every 20 days. Antibiotic baits were also provided once daily for three consecutive days to prevent disease. **1.2 Breeding and Hatching** **1.2.1 Intensive Cultivation** In November, sexually mature individuals (♀:♂ = 3:1) were selected from the domestication ponds and moved to a nursery pond for breeding. The breeding pond was covered with plastic film insulation, had a brick structure, and was filled with 20 cm of yellow mud at the bottom. A 1 m deep water area was maintained, along with a feeding table and sunning platform. A 20 m² sand spawning area was set up at one end. The water temperature was maintained at around 25°C, and the turtles were fed with animal feed, full-price feed, and green vegetation. Photosynthetic bacteria were added monthly to improve water quality. **1.2.2 Mating and Spawning** Under controlled temperatures, mating occurred when the water temperature ranged between 22°C and 25°C. About 15–20 days after mating, females began laying eggs, typically during the night. They climbed onto the sand, dug nests, and covered the eggs after spawning. **1.2.3 Artificial Incubation** An incubation room of 10–15 m² was built with heat-insulated foam boards. A small ditch was installed along the walls to hold water and fine sand. A UV lamp was used for disinfection, and an electric furnace regulated the temperature. Fertilized eggs were placed in wooden boxes filled with 3 cm of hatching sand, spaced 1 cm apart with the white spot facing up. The sand was covered with 10 cm of material and placed on an iron frame. Temperature was manually controlled, and the sand was kept at 4–5% humidity. After about 60 days, hatchlings emerged. **Results** **2.1 Domestication Results** A total of 964 wild mountain turtles were purchased, including 703 females and 261 males, giving a male-to-female ratio of 2.7:1. After over two years of domestication, 800 turtles were accepted, with an overall survival rate of 83.0%. Female survival was 88.6%, while male survival was 71.6%. **2.2 Egg Production Rate** Spawning occurred mainly in April and May, with most eggs laid by late June. Each female spawned only once per year. In the first year, 218 nests were recorded, and 309 females entered the nursery pool, resulting in an egg production rate of 70.6%. **2.3 Fertilization Rate** Each clutch contained 5–20 eggs, with an average of 15.6 eggs per nest. A total of 3,480 eggs were collected, of which 1,378 were fertilized, giving a fertilization rate of 39.6%. The range varied from 22.3% to 46.8%. **2.4 Hatching Rate** Of the 1,378 fertilized eggs, 1,225 hatchlings were produced, yielding a hatching rate of 88.9%. Only 2 malformed individuals were observed, accounting for 0.2%. **Discussion** **3.1 Morphological Features** The external features of S. sinensis include a round, flat shape, a wide and thick shell, and distinct granular scutes on the carapace. The ventral surface is grayish-white with scattered black spots, and the neck has rough, verrucous growths. **3.2 Ecological Characteristics** These turtles prefer quiet streams with slow-moving water. They primarily feed on snails, fish, and insects, with supplementary plant matter. Optimal growth occurs between 20°C and 32°C, with hibernation beginning below 12°C. They are docile but timid, and tend to stay close to the water. **3.3 Domestication Status** Males had lower survival rates than females, likely due to aggressive behavior and injuries during mating. **3.4 Spawning Test** The 70.6% spawning rate in the first year was considered normal, though some females may not have been fully mature. **3.5 Fertilization Rate** The low fertilization rate may be attributed to unsuitable environmental conditions or inadequate nutrition for breeding. **3.6 Hatching Rate** With proper sand size, humidity, and temperature, the hatching rate reached 88.9%, indicating successful incubation. This was the first year of the trial, and many aspects of domestication and breeding are still under investigation. Further research will focus on improving techniques to support large-scale conservation efforts.

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