نوع مقاله : مقاله پژوهشی
نویسندگان
چکیده
کلیدواژهها
عنوان مقاله [English]
نویسندگان [English]
The different aspects of aquaculture and biology of Tilapia have surveyed since 2008 at National Research Center of Saline Water Aquatics. In the present study, some limnological factors of earthponds and indoor tanks of Tilapia culture were investigated during the breeding season of 2016. In the earthponds, the minimum and maximum of water temperature ranges were 16.6-27.5 °C and 20.5-31 °C, air temperature 2-27 °C and 30-48 °C, dissolved oxygen in the morning and afternoon 2.11-10.19 mg/L and 7.06-14.64 mg/L, pH in the morning and afternoon 8.97-10.9 and 9.04-13, the depth of transparency 40-105 cm, salinity 7.94-8.82 ppt and ammonium density less than 0.05 mg/L to 0.4mg/L. The most abundant phytoplankton and zooplankton were Chlorophytes, Diatoms and Rotifers, and dominant macrobenthos were Chironomids. There was significant positive correlation between pH value with ammonium density and body length and weight, water temperature with total length, and negative correlation between dissolved oxygen and temperature and pH (p<0.05). In the indoor tanks, the ranges of water temperature was 24-29°C, the minimum and maximum air temperature 16-30°C and 30-43 °C, dissolved oxygen 1.65-8.38 mg/L, pH 7.25-9.37, salinity 7.7-7.94 ppt, ammonium 0.16-5.0 mg/L. There was significant positive correlation between water salinity with body weight and length and negative correlation between the amounts of dissolved oxygen with temperature, pH and total length (p<0.05). Growth proceeding of red Tilapia was more favorable in the earth pond. Tilapia culture in earth ponds has advantages especially for using water biomass by fish and lower costs of the structures, however indoor systems are preferable because of the possibility of two growing periods per year, water conservation and environmental considerations.
کلیدواژهها [English]
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