封闭循环水系统和船体网箱驯养圆口铜鱼幼鱼的效果比较

Domestication comparison of Coreius guichenoti in the closed recirculating aquaculture system and the boat- net trunk

以长江野生圆口铜鱼（Coreiusguichenoti）幼鱼（约150～400g）为试验对象，开展了封闭循环水系统和船体网箱驯养圆口铜鱼的比较试验。每种驯养条件下的试验鱼均按规格分2组进行驯养。封闭循环水系统中2组试验鱼的放养密度分别为11．48kg／m^3和17．65kg／m^3，驯养时问为279d，平均水温为（14．5±3．4）℃。船体网箱中2组试验鱼的放养密度分别为4．40kg／m^3和7．06kg／m^3，驯养时问244d，平均水温为（20．0±3．1）℃。所有试验鱼均采用人工配合饲料进行饱食投喂。结果显示，封闭循环水系统和船体网箱驯养试验鱼的成活率分别为97．75％和83．78％，且大规格试验鱼比小规格试验鱼成活率略高。封闭循环水系统中两组试验鱼的体重特定生长率分别为0．08％／d和0．11％／d，船体网箱中两组试验鱼的体重特定生长率分别为0．17％／d和0．21％／d。船体网箱试验鱼的丰满度总体大于封闭循环水系统的试验鱼。封闭循环水系统中全年未暴发重大疾病，船体网箱中暴发过一次较大规模的小瓜虫、车轮虫等寄生虫病。结果表明，封闭循环水系统驯养圆口铜鱼的成活率高但生长较慢，船体网箱驯养圆口铜鱼的生长优势明显但易遭受疾病侵袭。综合而言，封闭循环水系统和船体网箱养殖均是当前比较可行的圆口铜鱼驯养方式。

A comparative domestication study was conducted in the closed recirculating aquaculture system and the boat-net trunk using wild Coreius guichenoti juveniles( about 150 ~ 400 g) captured from the Yangtze River. For each aquaculture facility,experimental fish were divided into two groups based on fish size. The stocking density of the two groups of experimental fish in the closed recirculating aquaculture system were 11. 48 kg / m3 and 17. 65 kg / m3,and applied for 279 days with a mean water temperature( 14. 5 ± 3. 4) ℃. The stocking density of the two groups of experimental fish in the boat- net trunk were 4. 40 kg / m3 and 7. 06 kg / m3,and applied for 244 days with a mean water temperature( 20. 0 ± 3. 1)℃. All experimental fish were fed to satiation with artificial fodder. The results showed that the survival rate of experimental fish in the closed recirculating aquaculture system and boat- net trunk were over 97. 75% and over 83. 78%,respectively,and also showed a trend that smaller experimental fish had higher mortality. The specific growth rate of body weight of thetwo groups of experimental fish in the closed recirculating aquaculture system were 0. 08% / d and 0. 11% / d, while0. 17% / d and 0. 21% / d in boat- net trunk. The condition factor of the experimental fish in the boat- net trunk were generally higher than that of the closed recirculating aquaculture system. No serious disease was happened in the closed recirculating aquaculture system during the experiment,while in the boat- net trunk recorded a serious outbreak of parasitic diseases including Ichthyophthirius multifiliis and Trichodina. The present study indicates that Coreius guichenoti juveniles domesticated in the closed recirculating aquaculture system had high survival rate but slower growth rate,while had faster growth rate and more vulnerable to parasitic diseases when domesticated in the boat- net trunk. In conclusion,both of the closed recirculating aquaculture system and the boat- net trunk were suitable for Coreius guichenoti domestication at present.