نوع مقاله : مقاله پژوهشی
نویسندگان
گروه شیلات، دانشکده منابع طبیعی، دانشگاه تهران، کرج، ایران
چکیده
کلیدواژهها
موضوعات
عنوان مقاله [English]
نویسندگان [English]
It sees that with using water cress plant (Nasturtium afficinale) in an integrated fish and plant culture system, it would be possible to initiate an equilibrium ecosystem for culture of Rain bow trout fry. With running an experimental design, effect of different densities of water cress on fry (Oncorynhcus mykiss) and antioxidant capacity of water were evaluated in a water recirculating system. The treatments were different levels of Water cress; 0, 20, 40 and 60g plant separately introduced in each hydroponic chamber of experimental unit in triplicates. The survival of fish in treatment with 60g plant was significantly (p < 0.05) lower than other treatments and from 20 pieces reached to 15±1.24 pieces at the end of experiment. With feeding on the fish, the EC of water increased in all treatments without any significant differences (P>0.05). The highest and lowest EC of water recorded in treatments with 0 and 20 g plant with the rate of 594±60.51 and 580±82.31μs/m, respectively. Antioxidant capacity of water in treatments with 40 and 60 g plant reached to 414.75±15.90 and 414.75± 5.90 μm/l, respectively at the end of experiment. It was concluded that there is not any balancing between amounts of introduced plant and fish into the culture system, and nominated plant needed more concentration of nutrients for growth. The results of this experiment opened new vision of research to standard the water-born condition for growth of fish based on antioxidant capacity of water.
کلیدواژهها [English]