Traditional fish farming prevalent in the eastern sector of India in the homestead
ponds gave birth to extensive fish culture, when fry and fingerlings collected from natural
resources were stocked in ponds, large or small, in other parts of the country and the crop
harvested at the end of the year. Research and development activities initiated at different
research centers led to development seed production technology. Increasing demand for
protein food required increasing production through fish culture both in terms of volume by
covering as large a network of ponds/tanks as possible as well increasing production per unit
area. Research investigations in the 1950s and early 60s resulted in developing the nursery
and rearing pond management techniques leading to increasing the survival rates of fry and
fingerling that laid a solid foundation for the 3-tier system of fish culture.