Effect of different feeds and water salinities on the cyst production of brine shrimp, Artemia sp.

Effect of different feeds and salinities on cyst production in Artemia sp. was studied. Among the 12 different feeds used, ragi powder suspension showed the best growth and cyst production. A wide range of salinity from 90 to 210‰ was used to study its effect on cyst production. Among all these treatments, 130‰ salinity was found suitable for induction of oviparity and cyst production in the San Francisco Bay strain of Artemia sp.

Nutrient profile of pond water in north-eastern state of Tripura and impact of water acidity on aquaculture productivity

Physicochemical parameters of 31 fish pond water samples of Tripura were studied to ascertain the nutrient profile of acidic soil zone and the impact of water acidity towards aquaculture productivity. The pH was acidic (mean 6.63±0.44) with high Fe (mean1.04±0.40 mglˉ¹) and AI (mean 2.67±2.41 mglˉ¹) contents. These were mostly responsible for pond water acidity and poor productivity with low nitrogen, phosphate and total alkalinity. The study also showed strong negative relationship between water pH and redox potential (R²=0.5251). However, pH was positively significant with electrical conductivity. The roles of redox potential and electrical conductivity in water acidity were found highly important. Available calcium content was also found low (mean 2.91±2.96 mglˉ¹). Elevating level of pH of pond water could be the possible management practices in acidic water so that such unproductive water might be productive enough with higher phosphate and nitrogen levels for better biological production.