| 英文摘要 |
Abstract of "Studies on the technologies of aquacultural production and environmental factors": 1. "Study on the feed nutrition of Swamp eel, Anguilla marmorata" : Swamp eel larvae are abundant with reasonable price here in Taiwan, hence serve as potential culture species. The optimal level of protein from fish meal in the artificial diet for eel larvae at 51-54% causes the cost increased. In the present study, the eel were fed with the diets containing the substitution of eel fish meal with Lactobacillus fermented soybean meal at 0%、5%、10%、15%and 20% for 8 weeks. The results showed that the weight gain (116.9%) and feed efficiency (0.75) of the eel fed with diet containing 15% substitution treatment were better than other treatments. Therefore, we suggested that the eel fed the diet containing with 15% substitution fermented soybean meal can saving feed cost. During the cultivation, the water qualities such as water temperature, pH, dissolved oxygen, nitrite-N, ammonia-N were lower than the safe levels. To establish the cultivating system for cultivating the larvae stage of eel, the Pump driven by water level difference for breeding in order to save power consumption of the motor drive required were conducted. During the cultivation for four months, the survival rate of eel was 50%, and infections of red spot diseas, red fin disease, Edeardsiellosis, Dactylogyriasis, Trichodinosis resulted from the feeding of wild live worm (Tubifex hattai). In addition, it was observed that some eel revealed emaciation and high mortality by birnavirus infection. In cultivating system of eel, the over producing of mucus easily caused the deterioration of water quality and obstruction in circulation system. Therefore, in the present study, the low water level and water exchanged volume were conducted in the cultivation, which referred to the increase of water exchanging rate in the low water level to keep the clean water and to decrease the disease infection. 2. "Studies on the improvement of survival rate in cultured giant mottled eel" : This study investigated microbiological flora of moribund glass eels from nursing farm in Pingtong county in March and October, 2013. Major bacteria isolated were Aeromonas hydrophila、Edwardsiella tarda and Enterobacteriaceae species together with minor bacteria such as Pseudomonas spp.、Flavobacterium spp. and Vibrio spp. In addition, Trichodina sp., Ichthyophthirius sp., Dactylogyrus sp. and Lernaeid sp. were determined as the major parasites. Bacterins of A. drophila and E. tarda (2×109 cfu/g) encapsulated with cellulose acetate phthalate (CAP), and IgY preparation were used to immunize the eel and the efficacy of immune protection was determined at week 8. Good survival rates of 76-84% (RPS 70-82%) and high antibody titers were obtained. A regular use of probiotics exhibited better effect comparing to the control for water quality improvement and prevention of sediment deterioration regarding to the pH, ORP, ammonium and nitrite concentrations. 3. "The study and development in the techniques for sturgeon culturing" : Sturgeon is a high price and very popular food fish in the worldwide. With the economic development of oversea Chinese, the consumption of sturgeon is increasing and shows great growth potential. However, the sturgeon culturing requires strict conditions in the water temperature and water quality. In Taiwan, the increasing environmental temperature in recent years and the Sterptococcosis/ Aeromonasis-induced diseases which are tend to occur in summer have become the major challenges in sturgeon culturing. The aim of this study is to investigate the current status and bottleneck in domestic sturgeon culturing, and then develop the optimal formula of artificial diet and establish the techniques for production management and disease prevention through the experiments in hybrid sturgeon (Huso huso♀× Acipenser ruthenus♂). The results showed that the immunostimulant additive could effectively increase the immunity and survival, and the culturing standard operating procedure we built did improve the survival rate in the sturgeon culturing farm we counseled. By popularizing these culturing techniques, we expect it will increase the economic margin for farmers, and achieve the long term sustainability for Taiwanese farming industry. 4. "Study of production and management technology of Rock Porgy (Oplegnathus fasciatus)" : The purpose of this study is to collect rock porgy (Oplegnathus fasciatus) and nurture into broodstock. For determine optimal sex ratio in broodstock, and observe and record embryonic development period of change and time, as a basis for future artificial hatching technology. In addition, we also hope that the research and development of artificial rock porgy diet and nutritional needs. This project is designed feed different concentrations of protein diet to find out the optimal protein content for growth. Then, we use optimal protein content with different concentrations of lipid to find out optimal lipid for growth. This is for artificial diet of rock porgy development and manufacturing basis.In experiment 3-1, by using white fish meal as protein source, cod liver oil as lipid source, α-cellulose and α-starch as energy regulators, duplicate groups of juvenile rock porgy were fed with five groups of isocaloric diets containing the same dietary lipid level (8 %) but different dietary protein levels (35 %-55 %) with 5 % increment for 8 weeks. Analysis of weight gain by second-order polynomial regression indicated that the optimal dietary protein level of juvenile rock porgy was about 47.91 %. In experiment 3-2, by using white fish meal as protein source , cod liver oil as lipid source, α-cellulose and α-starch as energy regulators, duplicate groups of juvenile rock porgy were fed with five groups of isocaloric diets containing the same dietary protein level (48 %) but different dietary lipid levels (4 %-16 %) with 3 % increment for 8 weeks. Analysis of weight gain by second-order polynomial regression indicated that the optimal dietary lipid level of juvenile rock porgy was about 9.68 %. |