藻虾混养的研究　Ⅰ、江蓠与新对虾、青蟹在鱼塘中混养的试验

RESEACH ON POLYCULTIVATING SEAWEEDS TOGETHER WITH SHRIMPS Ⅰ. EXPERIMENTS OF POLYCULTIVATING GRACILARIA TOGETHER WITH METAPENAEUS AND SCYLLA IN FISHPOND

文中详述细基江篱繁枝变型与刀额新对虾、中型新对虾、锯缘青蟹在鱼塘中混养的试验。试验结果表明，藻虾混养构成海洋动植物互为有利的生态系，充分利用养殖水域，达到坛产坛收的目的。细基江蓠繁枝变型是鱼塘养殖的优良品种，从试验结果可推断出其生长的最适温度和盐度分别为17～30℃、17～29‰，它的最适生长水层是：1～4月为20～50厘米，5～6月50～80厘米、7～8月70～80厘米、9月35～70厘米、10～12月20～70厘米。文内还讨论藻虾混养的生态环境和共生关系、江篱的生长规律与藻种移植等问题。

The experiments of polycultivating Gracilaria tenuistipitata Chang et Xia f Liui Zhang et Xia f. nov., together with Metapenaeus ensis De Haan, M.interment dius Kishinouye and Scyla serata Forskal in a brackish water fishpond of Zhelang district, Haifeng couny, Guangdong Province were performed and the results are presented as follows.1. The brackish temperature of water in the fishpond is generally higher than that of the coastal water, especially during the months from May to Oct.. The opt imum temperature and salinity for the seaweed growth are in the ranges of 17-30℃ and 17-19‰ respectively, and these optimum ranges are suitable for the growth of Metapenaeus and scylla.2. The specific growth rate of the seaweed varies with the water depths and seasons. The optimum water depths for growth in the fishpond are 20-50cm dur ing the months from January to April, 50-80cm from May to June, 70-80cm from July to August, 35-70cm during September and 20-70cm after October, respecti vely.3. The annual yields per hectare are 6.9 ton of dry Gracilaria, 0.78 ton of Metapenaeus and 0.75 ton of Scylla. The profit coming from this polycultivating system is 35, 200 yuan (about 10,000 U. S. dollars) per hectare, which is higher than that in Taiwan and Indonesia. The experiments show that polycultivating seaweeds together with animals can promote their growth, hence increase yields and income as well as reduce costs. It is therefore a promising method in maricul ture production for developing countries.