How are wild Schizothorax prenanti domesticated? Keep the precautions firmly in mind

Schizothorax prenanti belongs to the Cyprinidae family, Schizothoracinae subfamily, and Schizothorax genus; it is also known as Yayu, fine-scaled fish, and carp. As market demand for Schizothorax prenanti increases, its natural resources fall short of demand. To meet the market need for Schizothorax prenanti, some areas in Sichuan and Chongqing have begun flow-through pond and cage culture. Schizothorax prenanti farming has developed fairly quickly in recent years, and its broodstock mostly comes from wild populations in natural waters. In order to scientifically and rationally protect and develop high-quality wild fish resources, the Make River Sichuan-Shaanxi Taimen Protection Center carried out experimental research on domestication and farming of Schizothorax prenanti from March 2006 to October 2007. The precautions for domesticating wild Schizothorax prenanti are introduced below:

I. Selection of wild broodstock

The broodstock comes from the Make River in the upper reaches of the Dadu River, caught with single-layer gill nets or three-layer gill nets, or by fishing. Choose high-quality, robust fish with relatively minor injuries as the domestication subjects.

II. Domestication site

Either ponds or flow-through ponds are acceptable; the area should not be too large, so it is easy to manage. In the early stage of domestication, shade facilities should be set up over the pond to avoid direct sunlight and the influence of human activity at the pond edge on the broodstock, keeping things as quiet as possible so they can adapt to the new environment as quickly as possible. At the same time, birds should be prevented, because during the domestication process it was found that birds preyed on the fish in the pond.

Before filling with water, thoroughly clean the pond and expose it to the sun. Fill with water a few days before the broodstock are put in, so that some algae grow on the pond walls. If it is a cement pond, appropriately lay cobblestones to prevent the wild broodstock from scraping their bodies while adapting to the new environment.

III. Mixed-species domestication

To speed up the domestication of wild Schizothorax prenanti, fish with similar feeding habits were used together for domestication. During the domestication process, Schizothorax davidi was stocked. Compared with Schizothorax prenanti, Schizothorax davidi is easier to domesticate, has a strong ability to adapt to a new environment, and has a strong ability to seek food. After being put into the pond, 3 to 5 days later it actively went to a fixed feeding table to seek food. As batches of Schizothorax davidi fed, Schizothorax prenanti also fed along with Schizothorax davidi, and the domestication speed accelerated.

The feeding table is sewn from bolting silk, 50 cm in diameter, round; after feed is put in, it is set 10 to 20 cm from the bottom of the pond. The feed used is carp feed.

IV. Strengthen daily management

Schizothorax prenanti likes counter-current water and is good at jumping. A trash rack net should be set at the water inlet or inflow opening to prevent broodstock from jumping out against the current, and at the same time to block weeds, branches, fallen leaves, and so on in the water flow. An escape-prevention net should be set at the drainage outlet. Promptly remove leaves, residual feed, dead fish, and so on from the pond.

Clean the feeding table at irregular intervals; after washing it clean, expose it to the sun before using it again.

V. Disease prevention and control

During the domestication process, the period of high mortality is 3 to 10 days after being put into the pond, and the main disease is saprolegniasis. It is caused by infection by water mold due to injuries to the fish body surface during catching and transport, loss of scales, or collision injuries from jumping against the current.

Before the broodstock are put into the pond, use a 1:1 mixture of sodium chloride and sodium bicarbonate at a concentration of 8 mg/L and bathe them for 2 hours. For injured areas on the body surface, wipe them dry and apply erythromycin ointment, or mix dissolved methylene blue with vaseline and apply it to the wound.

After being put into the pond, splash methylene blue over the whole pond every two days at a concentration of 2 to 3 mg/L, splashing 3 times.