Biodiversity and spatio-temoral varaitions in Periphyton of river Ganga (Gangotri to Vindhyachal).

Abstract

This is to study spatial and seasonal distribution pattern of periphytic taxa from Gangotri to Vindhyachal, as periphyton is important food for nibbling fishes like Rita rita and Botia sp. As diversity of river source create numerous habitat that contribute to structural diversity of spatial pattern in richness, density, taxonomic composition and distribution of periphytic flora. During summer periphytic deposition ranged from 170 ucm-2 (Gangotri), to 19180 ucm2, in winter it ranged from 60 ucm-2 (Gangotri), to 17340 ucm-2 (Kanpur bb), in monsoon from 20 ucm-2 (Gangotri), to 17390 ucm-2 (Farrukhabad). Centers of higher abundance were Farrukhabad, Kannauj, Kanpur, Allahabad, Tehri and Srinagar. It can be concluded that Ganga at Kanpur and Farrukhabad exhibited continuous higher periphytic abundance (density) in all the seasons. Most of the centres revealed higher diversity during summer, except Kanpur where maximum diversity was noticed in winters. Total 77 periphytic taxa were recorded belonging to various taxonomic groups(Bacillariophyceae-28, Chlorophyceae-21, Myxophyceae-12, Dianophyceae-12, Euglenophyceae-3, Protozoa-8, and Rotifera-3) having various species Bacillariophyceae was dominant at all the centres in monsoon and winter, but in summer season some centers revealed dominance of Chlorophyceae (Srinagar ab and bb) and Myxophyceae (Deoprayag, Narora bb, Farrukhabad and Allahabad). In our studies most abundant periphytic diatoms were Synedra, Cymbella Cyclotella, Gomphonema, Nitzschia and Navicula. Among them Synedra was omnipresent. From Gangotri to Narora bb Cymbella contributed as dominant taxa, but from Kanpur to Vindhyachal it was not observed as dominant taxa, instead of Cymbella, Nitzschia was most abundant.