Artificial silkworm breeding technology

Nereis is an invertebrate of the Annelidae, Polychaetea, Lembodontidae and Nereisidae, and there are more than 80 species in China's coastal areas. The cocoon is like a worm and its body is composed of many body segments. Sandworms inhabit the sediment and move with the fluctuation of the tide. The larvae feed on low-algae species. After sneaking into the sediment, they use spices and plant and animal debris as spices. They are omnivorous animals. The ability to adapt to temperature and salinity is relatively strong, mostly dioecious, no obvious reproductive system, only the formation of gonads in the pre-genital period, changes in body color or shape. The eggs that are discharged at a water temperature of about 20°C can hatch for 3 to 5 days. After hatching, they can infiltrate into the sand for 9 to 14 days. In the natural environment, it is mostly one year old, and it dies after spawning and mating. The silkworm grows rapidly and can reach commercial specifications for several months. 1. Extensive earthen pond aquaculture (1) Selection of aquaculture sites According to the ecological habits of Nereis, it is convenient to enter and drain the aquaculture sites without industrial pollution. The sediments of the ponds are mainly fine and soft clay. After the site is selected, the first step is to carry out Mechanical plowing, loose soil, a depth of about 30 cm, in order to facilitate the habitat of Nereis larvae. Plowing good ponds use quicklime and bleach to kill enemy pests. (2) Within one week before the fertilization of the larvae of nymphs, 450 to 750 kg/ha of organic fertilizer should be applied to increase the primary productivity of the earthen pond in order to cultivate the food organisms of the silkworm. The stockings were Ganglonia. From September to October, the density was 250/m2. After releasing the seedlings, fertilization was conducted once in spring, autumn and winter. Fertilizer was 750 kg/ha of fermented chicken, duck, and 450 kg/ha straw. The use of low-value bait, such as rapeseed meal, bean cake, cornmeal, or feed scrap, meets the nutritional needs of the silkworm, and the amount of feed is adjusted according to the condition of the beach surface and the growth of the silkworm. (3) After the stocking sites are ready, the artificially bred strains will be stocked in large-scale earthen ponds. This type of cultivation requires strict requirements for clearing the ponds and water intake, and the inlet and outlet gates must be separated, and the inlet gates should be installed. The 60-mesh sieve and net are installed in the 100-mesh screen to ensure that the predator cannot enter the soil pool and prevent the juveniles of the silkworm from draining from the pool. 2. Factory-based artificial breeding This method was first seen in Japan in the 1980s. It was first artificially reared indoors, then stocked with seedlings. When the nursery was raised, the pool was not sanded. When the seedlings were cultivated, about 30 cm of rough sand was laid. . Daily water change, feeding 2 to 3 times, coupled with inflatable equipment, as long as the water supply is timely, the temperature is appropriate, the density is reasonable, enough food, 6 months to develop product specifications, the output is generally 3 kg / square meter. The silkworm broodstock used for reproduction can be purchased directly before the breeding season every year before the breeding season. The broodstock requires a strong, complete, and responsive body. The acquired sandworms generally do not reach the isoforms and need to be stocked. When stocking, it can be directly put into the rearing pond, or it can be carried out in the concrete tank or the 40-mesh large cage. The water depth requires 40-50 cm and the density should not exceed 2-3 kg/m2. Change the water every 2 to 3 days, and feed the yeast powder, bean cake and other bait. After the silkworm has reached the isoform, use a net to collect and use it for the breeding of the silkworm larvae. 3. Methods of capture There are two common methods of capture. One is to capture by hand. The silkworm burrows in the mud, heads and tails, and the depth is 25-40 cm. In the soft sediment, it can be dug directly with both hands. The second is excavating with shovels, pointed spades, or three-tooth rakes, which can be excavated quickly with the ebb tide.

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