In an attempt to improve the stocking size and yield of Clarias gariepinus, small fingerlings (average weight=3 g) of the type usually produced by African hatcheries were stocked together with tilapia (Oreochromis niloticus) broodfish at a ratio of 1 g of fingerlings to 3.64±0.39 g of broodfish. Holding ponds were so prepared that persisting leaks did not cause water level drops of more than 2 cm/night and water temperature, pH and transparency respectively averaged 27.3°, 6.5 and 20.8 cm. Results showed that C.
Md. Mosaref Sikdar lives in Islampur village in Patuakhali district of Bangladesh. Nearly 15 years ago when Mosaref launched his carp nursery on a small pond, he had no access to aquaculture training sessions. He worked without prior knowledge or external assistance of any kind.
Jessore district in southwestern Bangladesh is an important source of fish seed in the country. However, hatcheries here have high mortality rates due the quality of the water being pumped from underground reserves.
Oxygen concentration in this water, which is used in brood and nursery ponds and incubation jars, is very low, while the levels of dissolved carbon dioxide are high. This is an unfavorable combination that leads to very low survival rates of hatchlings, even from the best quality eggs and resultant economic losses.