Document Abstract
During the entire study period, total no. of 39 fish species belonging to 13 families were
recorded, Cyprinidae was the largest family contributing 16 species .Family Cyprinidae was represented by
the Esmosdandricus, Catla catla, Cirrhinus mrigala, Labeo rohita, ,Labeo calbasu, Labeo bata, Labeo
potal, Labeo pungucia. Labeo gonius,
Aspidoparia jaya, Cyprinus carpio, Cirrhinus reba, Ctenopharyngodon idella, Puntius ticto, Puntius
punctatus, Hypothalmichthys molitrico, Oxygaster bacaila, Lepidocephalichthys guntea is Cobitidae, In
Notopteridae two species Notopterus notopterus, Notopterus chital. In Siluridae Ompok bimaculatus. In
bagridae four species ,In Mastacembelidae , Mastacembelus armatus, in Clarridae, Clarius batracus and
Clarias gariepinus ,Belonidae has one species Xenentodon .The observations recorded in the present study
may provide valuable evidence of slight change in morphological structure of fish species due to the
environmental condition in the locality, also a new species have been observed knows as Labeo potail. Hilly
area, depth, temperature, turbidity is the important physical parameters on which the fish diversity of area,
but the changes are not much diverse to give rise to new species. Only slightly, morphological changes are
generally observed from those fish species living in down hill areas of Mainpat. The physico-chemical
parameters of water fall varied seasonally such as Temperature, Turbidity, Ph, Dissolve Oxygen, CO2,
Hardness, Transparency, Nitrate, Chloride, Conductivity, TDS, Alkalinity, also it affects and determines the
fish diversity.