Abstract
Studies on the bottom fauna in a tropical fresh-water fish pond were carried out during the period of January to December, 1971. Total volume of the bottom fauna was the highest in January and the lowest in October. Numerical abundance (population density) of the benthos varied from 186 to 385 organisms per sample. The maximum number was recorded in July and the minimum in November. The percentage composition of Chironomus larvae fluctuated from 11.6 per cent to 88.3 per cent, crustaceans varied from 4.3 to 25.0 per cent, oligochaetes varied from 6.2 to 63.3 per cent and the percentage of molluscs ranged from 1.6 to 5.8 per cent of the total benthos. Chironomus larvae were abundant throughout the period of studies. Crustaceans were abundant during summer months while the oligochaetes and the molluscs were plentiful during the monsoon months. The bottom fauna recorded in the present studies included one copepod, four species of ostracods, six species of oligocheates, five species of molluscs and Chironomus larvae.
