K. Singh a, K. K. Pandeyb, S. Narayanc, S. Saifd , Janardan Jeee & Chandrawati Jee f
a Faculty Dept. of Biotechnology A.N. Collage, Patna.
bResearch Scholar, Dept. of Biotechnology A.N. Collage. Patna.
cResearch Scholar, Dept. of Botany A.N. Collage, Patna.
dFaculty Dept. of Biotechnology A.N. Collage, Patna.
ePrincipal Scientist, ICAR, Eastern Zone, Patna.
f Dept. of Biotechnology A.N. Collage, Patna.
Received 5th June, 2008; Revised 25th August, 2008
Abstract : The influence of some limnological factors on abundance of benthic macro invertebrates in two different selected ponds, one managed and one unmanaged were studied from July, 2005 to June 2007 in Patna. The physico-chemical characteristics of water were estimated and correlations with benthic faunal communities were studied. It was observed that, the physico-chemical characteristics of water have a direct relationship with the faunal composition of ponds. Altogether 20 species of macroinvertebrates belonging to five classes were recorded in the two ponds during investigation periods. The distribution pattern of macroinvertebrates inlisted were, 4 species belonging to class Oligochaeta, 1 species to Hirudinea, 6 species to Insecta, 8 species to Gastropoda and 1 species to Pelecypoda. The number of macroinvertebrates recorded were 18 species in Pond I and 12 species in Pond II, although the distribution pattern was different in both the ponds indicating that species diversity is greatly influenced by limnological factors. In Pond 1, Gastropods were most dominant followed by organisms of class Insecta and Oligochaeta. The highest number (13696 ind./m2)of macroinvertebrates was recorded in Pond I during December and minimum number (1970 ind./m2) was observed in August. On the other hand in Pond II, the highest number (7097 Ind./m2) was observed in January and lowest number (1146 ind./m2) in August. The most dominant species was that of class Gastropoda followed by class Insecta and Oligochaeta. Some of the macroinvertebrates especially Oligochaeta (Tubifex and Limnodrilus haffameisteri) which serve as organic pollution indicates were also recorded in the pond. Some physico-chemical parameters analyzed were Temperature, Transparency, pH, DO, BOD, COD, DOM, Hardness, Calcium, Magnesium, Chloride, So4-S, Po4-P & No3-N. showing different concentration in both ponds.