A Study on the Effects of Some Physico-Chemical Parameters on the Abundance and Distribution of Zooplanktons of a Village Pond "Dauna"

Abstract

The present study entitled "A study on the effects of some Physico-Chemical parameters on the abundance and distribution of zooplanktons of a village pond Dauna" was carried out from 3rd July 2002 to 18th December 2002.Variation in water colour, depth, nature of the day, temperature and transparency was noted in summer and winter seasons. The average pH ofthe pond water was 7.4(6.2-8.6), dissolve oxygen was 6.35ppm (4.3-8.4ppm)where as free CO was 17 ppm (4-30ppm). The total alkalinity recorded was 51 ppm (33-69ppm) and total hardness was 44.5 ppm (35-54ppm). The dissolved calcium varied from 7.5 to 16.4 ppm and chlorides from 21 to 38 ppm. Positive relationship of zooplankton population density was foundwith depth, transparency, air and water temperature, dissolved oxygen, pH,dissolved calcium and chlorides where as negative with free carbondioxide,total alkalinity and total hardness. A total of ten genera of zooplanktonbelonging to five taxonomic groups were found. The zooplankt on composition of the pond was contributed by two genera of protozoa(Paramecium sps. and Vorticella sps.), two genera of cladocera (Daphniasps. and Moina sps.), two of rotifera (Keretella sps. and Brachionus sps.),oneostracode (Cypris sps.) and three copepodes (Cyclopus sps., Diaptomussps. and Nauplius sps.). The total density of zooplankton was 8006 no/litwith an average value of 667.16 no./lit. The maximum abundance (913no./lit.) was counted in the month of Julyand minimum (412 no./lit.) was on18th October 2002. Of five groups of zooplanktons, rotifera dominated other groups.