Research And Preliminary Application On Artificial Breeding Technology Of Plagiognathops Microlepis

Plagiognathops microlepis mainly lives in the Changjiang River, the Zhujiang River and Amur River etc.. It is classified into small and medium size commercial fishes which mostly live by organic detritus, humus and blue algae, and they can make a positive effect for water purification and amelioration. A bigger output is expected to get by rising the density of Plagiognathops microlepis in the pond and feeding them natural foods. So, Plagiognathops microlepis, named as the ecological fish and environmental protection fish, has high level of economic benefits, social benefit and ecological benefit.3,120protospecies fingerling of Plagiognathops microlepis in a size of2.5cm～3.0cm were introduced from national xenocypris seed multiplication farm in Liling City, Hunan province, into Guangxi on June,2008, which aims at rearing Plagiognathops microlepis fingerling to parent fish. Based on related biology and ecology researches, artificial propagation, seed rearing and practical aquaculture experiments were proceed. during research period for three years, eleven batchs of fishes have been gotten by artificial propagation, and the batch of fishes that were treated with mixture of DOM3mg/kg+LRHA23mg/kg+PG1mg/kg got the best effects of hasten parturition whose results were98.1%female spawning rate,77.6%fertilization rate,76.9%hatchability rate and8.06million hatched fishes.Four days after hatching, fry were released into the pond. On their body length of2.0cm-2.5cm, the result is6.3million fishes and78.1%average surviving rate; on body length of more than5cm, average surviving rate is84.3%. Fingerlings after transport strengthen training has99.85%surviving rate. An additional output of15.84t Plagiognathops microlepis were gotten at33.33hm2polyculture-pond with no increaseing feedingstuff can be increase produces, and it takes2.5%of the total output.Reservoir transplant experiments were performed with these parameters of591.2hm2reservoir,600tails/hm2-900tails/hm2Plagiognathops microlepis in a size of5cm-8cm, the results showed that the dominant specis of fish got822t ultimate output similar to the number before the Plagiognathops microlepis were transplanted, but an additional77.5t output of Plagiognathops microlepis was gotten, which made a profit of2.0797million yuan more than before. Phytoplankton testing result revealed that the total number of phytoplankton and humid weight didn’t decrease after Plagiognathops microlepis were transplanted, but cyanophyta and euglenophyta showed a decreasing trend, which proves that Plagiognathops microlepis can reduce the density of cyanophyta and euglenophyta. The river releasing experiment of Plagiognathops microlepis also showed that the breeding of Plagiognathops microlepis could increases catch yield in the river and control the growing of Limnoperna lacustris(Martens).The results indicated that the technology of artificial propagation, fish breeding and aquaculture were matured in Guangxi for Plagiognathops microlepis. The applications of these technologies will play a role in promoting aquaculture industry structural adjustment of Guangxi and increasing worker’s production and income.