BASIC STUDIES ON THE DEVELOPMENT OF CLOSED ECOLOGICAL RE CIRCULATING AQUATIC ANIMAL CULTURE SYSTEMS

作为受控生态生命支持系统(CELSS)模型的一部分，在水圈内开发了一个封闭的生态循环水产养殖系统(CERAS)，用于浮游植物、浮游动物和鱼类等水生生物。采用带O2/CO2交换装置的密闭养鱼池，研究了不同光照周期(3L：3d；6L：6d；12L：12d；24L：24d)对尼罗罗非鱼幼鱼和成鱼代谢率和能量损失的影响。这项研究表明，如果这种鱼暴露在较长的光周期而不是较短的光周期中，能量节约将是可能的。罗非鱼幼鱼的静息呼吸频率高于成鱼。在该封闭系统中，罗非鱼在189d的生长周期中，生长正常，饲料效率高于循环敞开式罗非鱼。在长期的罗非鱼养殖试验中，还对密闭式养鱼池中磷的形态和矿物质收支进行了评估。废物中的几种元素需要电离和/或补充，以作为密闭养殖系统中藻类的营养物质。罗非鱼从幼体到成鱼只能养殖钝顶螺旋藻。这一结果表明，在CERAS中，从外源投喂开始，就可以利用生螺旋藻构建罗非鱼食物链。最后，研究了CO2和O2浓度和光照强度对细小眼藻生长的影响。在浓度为4%CO_2、21%O_2、100μ摩尔分数S的条件下，48h细胞增殖率最高，细胞数增加了8.3倍。

A closed ecological recirculating aquaculture system(CERAS), a part of the models of a controlled ecological life support system(CELSS), was developed in the hydrosphere for aquatic organisms such as phytoplankton, zooplankton and fish. Using a fish-rearing closed tank(air-tight tanks)with an O_2/CO_2 exchange unit, the influence of different photoperiod cycles(3L : 3D ; 6L : 6D ; 12L : 12D ; ＆ 24L : 24D)on the metabolic rate and energy loss of young and adult tilapia Oreochromis niloticus was investigated. This study suggested that energy conservation would be possible if this fish is exposed to longer cycles of photoperiod rather that shorter ones. Resting respiratory rate of young tilapia was higher than that of adult one. In this closed system, tilapia showed normal growth and high feed efficiency compared with the recirculating open tank under a high concentration of NO_3-N over the 189-day period. Phosphorus form and mineral budgets in the fish-rearing closed tank during a long term experiment with tilapia were also evaluated. Several elements in the wastes require ionization and /or supplement, to serve as nutrients for alga in closed culture systems. Tilapia can be cultured only Spirulina platensis from larvae to adult. This results suggest that it is feasible to construct a food chain using raw Spirulina to feed tilapia from the onset of exogenous feeding in a CERAS.Finally, the effects of CO_2 and O_2 concentrations and light intensity on growth of microalgae Euglena gracilis were investigated. The multiplication rate of cells was highest and the cell number increased by 8.3 times during 48h under a condition of 4% CO_<>, 21% O_2 and 100μ moll m^<-2>s^<-1> PPF.This study obtained many basic and useful informations to develop CERAS.