Artificial domestication and breeding technology of Yellow Shell Fish in Baoshan Mountain
Kong Lingfu and so on
Yellow shell fish is a local name, scientific name Baoshan four-whiskered catfish (Barbodeswynaadensis), belongs to the cyprinid family, catfish subfamily, new light lip fish genus [Yoshiyama Huayao self-media network debut]. It is a unique river indigenous fish in Yunnan Province, and is only distributed in the Nu River system in Yunnan. The distribution range is relatively narrow, the population is relatively limited, and it has been included in the list of aquatic wildlife protection in Yunnan Province. Because of its large size, tender flesh, delicious taste, beautiful body shape, bright color, and traditional medicinal food value, it has always been favored by the local people and is a fish with high development prospects. The fish is fusiform, similar to the shape of a mud carp, with a lower mouth, a blunt snout, a smooth snout, and sometimes white warts in front of the eyes, irregular arrangement, and uneven density; 2 pairs, more developed; the caudal fin is forked, and the upper lobe is slightly longer. Adult fish are larger in size, the body color is blue-blue when living, the abdomen is white, the scales are larger, the lateral scales are yellow, and the water is observed as a yellow longitudinal band, so it is named "yellow shell fish".
In recent years, there have been some studies on the cultivation of four-whiskered catfish, disease prevention, biological characteristics, metabolism, physiological functions, etc. The artificial domestication technology of yellow shell fish effectively increases the number of yellow shell fish populations, promotes the protection, domestication and development and utilization of yellow shell fish species resources to be better carried out, and makes them suitable for breeding and production on the basis of effective protection, so that the resources of yellow shell fish species can be further effectively protected and rationally developed and utilized, ecological balance is maintained, the process of fishery industrialization is accelerated, local aquatic products are cultivated, and the development of fishery industrialization is promoted, and at the same time, greater economic value is created for society.
1 Materials and methods
1.1 Base construction
Select areas with fresh water quality, sufficient water quantity and convenient transportation for base construction, and establish artificial simulated spawning ponds, hatchery ponds, broodstock breeding ponds, induction ponds, juvenile fish breeding ponds, live bait breeding ponds, and aquaculture storage sedimentation ponds related facilities for artificial domestication and breeding of yellow shell fish.
1.2 Construction of domestication ponds
Select the pond with suitable water temperature, moderate area size, fresh and sufficient water source and quiet environment as the domestication pond, disinfect the domestication pond before use, plant aquatic plants in the pond, set up hidden objects, create artificial caves to simulate the artificial ecological environment, and keep the water temperature of the domestication pond between 24 and 30 °C, the dissolved oxygen amount is above 4 mg/L, and the pH value is between 6.5 and 8.5.
1.3 Collection, harvesting, domestication and breeding of wild yellow shellfish
In 2001, Lincang Fisheries Station collected 1 200 "yellow shell fish" fry from Zhenkang County to the Lingshan Temple breeding base in Linxiang District for artificial domestication and breeding. Two trials of induced reproduction were conducted, one at the base of the Lincang Fisheries Station and once at Zhenkang, but they were not successful due to the insufficient maturity of the parents' eggs. Since January 2002, through the artificial field collection method of The Fisheries Station of Zhenkang County, a total of more than 30 000 fish have been collected, and they have been artificially domesticated in the Old Agricultural Science Institute of Fengwei Town, the Fengwei Agricultural Bureau, the Junlong Hot Water River "Yellow Shell Fish" Breeding Base in Nan umbrella town, and the Base of Nan Umbrella Reservoir. After the collected wild yellow shell fish is washed and disinfected with 3% salt water, it is put into the domestication pond for broodstock domestication, the domestication process is mainly fed with compound feed, using an automatic bait machine to feed regularly, 2 to 4 times a day, the daily feeding amount is 1.5% to 2.5% of the overall quality of the eating fish; wherein the weight percentage of the compound feed is: fish and shrimp 30% to 40%, insects 5% to 10%, the surplus is conventional green feed; 1 time a day to feed green feed, first feed fish shrimp and insect bait, and then feed green bait.
1.4 Day-to-day management
The water level of the domestication pond is controlled at more than 1.2 m, with the growth of fish, the temperature rises, the summer deepens to more than 1.5 m, the transparency is controlled at 30 to 35 cm, the main growing season changes the water once every 10 to 15 days, the aerator is opened in time at noon and rainy days in the summer, and every 20 to 30 days sprinkled with quicklime once to maintain the water quality "live, tender and refreshing"; keep regular patrols of the pond, observe the feeding and activity of the fish, and remove the remaining bait or dead fish in the cage in time. [Yoshiyama Huayao self-media network debut]
1.5 Artificial domestication and breeding
The living water temperature of "yellow shell fish" is 8.5 ~ 36 °C, the suitable water temperature is 24 ~ 30 °C, the requirements for dissolved oxygen in the water body are relatively high, generally above 4 mg/L, and the pH value is between 6.5 and 8.5. Omnivorous is partial to carnivorous, green feed such as vegetable leaves, plant seeds such as corn and wheat, and animal raw materials such as fish and shrimp and insects can be eaten, and pellet feed can also be eaten. The breeding season is from May to October of each year, which is the local rainy season, and two breeding peaks are formed at the beginning and end of the rainy season, and eggs are laid in batches. The male is sexually mature in the second instar and the female in the third instar. Eggs are laid in batches, with thicker abdominal muscles, and during the non-reproductive and reproductive seasons, males and females are difficult to distinguish from appearance. During the breeding season, mature males can squeeze out milky white semen, the wart grains on the head are relatively rough, the mature females have softer and slightly expanded abdomen, and the warty grains on the head are not too rough. When the egg is just fertilized, the egg is slightly sticky, and the stickiness disappears after absorbing water, making it a sinking egg.
1.5.1 Artificial induction of labor The luteinizing hormone-releasing hormone analog (LRH-A2) and diosterone maleate (DOM) are used as induction drugs. Females are injected twice, with the first dose of LRH-A2 at a dose of 5 to 10 μg/kg for females. The second dose is given LRH-A2 + DOM at a dose of 3 to 5 micrograms (LRH-A2) + 3-5 mg (DOM)/kg for females. The first and second injection time is generally 12 to 24 h apart, and the injection site is the chest cavity, and the injection is avoided from light and sun. After the second injection of the female, the male may also halve the dose according to maturity, or reduce the dose appropriately or do not inject it.
1.5.2 Artificial insemination incubation Dry artificial insemination is used. Select the mature female fish, squeeze the fish eggs into a dried white porcelain bowl, squeeze in the male semen, stir well with chicken and duck feathers, then add normal saline and stir well, rest for 1 to 2 minutes, then add the water in the pond to stir well, stand still for 1 to 2 minutes, make it fully fertilized, and pour off the sewage. Repeat the eggs with water 2 to 3 times before moving into the incubator for incubation. 300,000 eggs are produced and 60,000 fry are hatched.
1.6 Seed rearing of "yellow shellfish"
Cultivation water quality is required at a water temperature above 18 °C. The "yellow shellfish" seed opening bait is zooplankton, and salt duck egg yolks can also be used as open bait. After a week, rotifers, branches and copepods are fed, as well as fish pulp, powdered feed, animal blood, etc. It is also extended to pond culture and cage culture, where daily bait accounts for 3% of the mass of the fish.
2 Test results
From September 2011 to October 2013, 35 artificial induction trials were conducted. Breeding test 5 times. 300,000 eggs were produced and 60,000 fry were hatched, with a hatching rate of 20%.
3 Discussion and conclusions
In the process of collection, harvesting, domestication and breeding of wild yellow shellfish, in order to maintain the rapid growth of fish bodies and simulate the wild environment, the broodstock domestication pond is set up with flowing water. Water flow is an important ecological factor in the living environment of fish, which can stimulate the sensory organs of fish to produce corresponding behavioral responses and activity modes, and then affect the feeding, growth, metabolism and other life activities of fish. Under breeding conditions, the water flow directly affects the swimming movement of fish, and the increase in movement will affect its metabolism and physiological function, which in turn affects the growth and development of fish.
In order to save costs, with full-price sinking particle bait as the mainstay, with the breeding method of green bait, the weight percentage of the full-price sinking granule bait is: fishmeal 10% to 17%, eggshell powder 12% to 23%, polyvitamin 4% to 8%, dried bread worm powder 16% to 20%, seaweed powder 9% to 18%, wheat bran 18% to 24%, yeast 7% to 12%. The full-price sedimentary granule bait is fed with allicin powder in an amount of 0.2 g/kg of fish body mass and fed once a month.
Wild yellow shellfish collected are young fish and are preferable before sexual maturity. It is better to domesticate and cultivate and retain it as a breeding breeding fish than to breed wild mature breeding fish.
During the test, the water temperature was above 26 °C, continuous oxygenation, dissolved oxygen was more than 6 mg/L, and the pH value was between 7.2 and 7.8, but the water temperature of 26 to 28 °C was the best for the survival performance of the fish.