Optimization Of Parthenogenesis Conditions And Selection Of High Effective Bait In Large-scale Culture Of Artemia

As an important food in aquaculture,Artemia resources and environment are destroyed by the unreasonable breeding methods and overfishing,natural Artemia resources are facing depletion.In recent years,due to the rapid development of aquaculture and uneven quality of Artemia eggs,the demand for high-quality Artemia eggs is increasing.The current research for Artemia focus on the enrichment of heavy metal ions.There are few reports on the Parthenogenesis and the high-efficiency food application of Artemia.In this thesis,by comparing several strains of Artemia egg which was widely used in the world,find the most suitable strains for large-scale application under local ecological conditions.Explore the conditions and methods of indoor environmental culture of Artemia parthenogenetic and the effects of different diets on its growth;Combined with outdoor small-scale culture,observe the impact of environmental factors on Artemia growth and oviposition of Artemia.It provides reference for indoor high-density culture and outdoor large-scale culture.The hatching rate of Artemia eggs in the salt lakes of Uzbekistan,Kazakhstan,Russia and Bohai Bay were tested under the set conditions,The results showed that the hatchability(?88%)of Artemia parthenogenetic in Bohai Bay were significantly higher than that of other species(P<0.05).The Artemia parthenogenetic strains were selected as the best Artemia species for subsequent experiments.By studying the growth rate and other biological parameters of Artemia parthenogenetic in Bohai Bay under different salinity gradients,it is concluded that the optimal growth rate of Artemia in high salinity gradient(60 ppt ? 100 ppt)is better than that in low salinity gradient(40 ppt)at 20°C?24°C.By comparing the feeding effects of five different diets-photosynthetic bac teria,Wheat bran,Soybean residue,Nannochloropsis and biogas fluid on Artemi-a parthen-ogenetic,It was found that under the conditions set in the laboratory,the growth rate of Artemia feeding Nanno-chloropsis was the highest in 3?8 days at the beginning of the experiment(P<0.05);After 8 days,the feeding eff ect of Soy bean residue group was the best,the survival rate of Artemia was h igh and it was not easy to die and the growth rate was better than the other groups(P<0.05).By measuring the changes in population density and body length of Artemia under the action of different diets,contrasted with the changes of temperature and salinity,Summarizes the objective law of the growth and development of Artemia outdoor,from the middle of July to the end of August(also known as the solar term of summer rest),Due to dramatic changes of temperature and salinity,the offspring of Artemia changed from oviparous to ovoviviparity,The female Artemia produced nauplii directly in the oocyst and the The output of Artemia eggs dropped sharply.After the middle of August,with the arrival of rainy season,Artemia resumed its oviparous method and the number of eggs laid increased.Therefore,during the resting in the dry season,Food must be supplemented manually to make sure Artemia has sufficient nutrients to maintain growth and reproduction,provide population basis for production after the long period of hot weather.According to the statistics analysis the length of Artemia,the number of Artemia population and the amount of eggs in the experiment pond fed with different kinds of diets(wheat bran,soy bean,chemical fertilizer and chicken manure),it was found that the fastest increase of population density in a short time was chicken manure diet group.However,With the increase of population density,food began to run short,caused a large number of Artemia died from starvation.When the test period is extended,the population density and length of Artemia in the diet group fed with Wheat bran and Soybean residue were significantly higher than those in other groups,which has a good production prospect and application value.