Diversity and community composition of ichthyofauna at Konhaye Stream, district Dir Lower, Pakistan

This study was undertaken to investigate the diversity, abundance ratio, and distribution of the fish species and to record the water quality of Konhaye Stream, district Dir Lower, Pakistan. A total of 16 fish species were recorded, belonging to 4 orders (Cypriniformes, Channiformes, Siluriformes and Mastacebilformes), and 5 families including Cyprinidae (Schizopyge esocinus, Racoma labiata, Cyprinion watsoni, Cyprinus carpio, Barilius pakistanicus, B. vagra, B. modestus, Crossocheilus diplocheilus, Garra gotyla, Puntius ticto, and P. sophore), Channidae (Channa punctatus and Channa gachua), Nemacheilidae (Schistura macrolepis), Sisoidae (Glyptothorax punjabensis), and Mastacembelidae (Mastacembelus armatus). Different ichthyo-diversity indices [Simpson's biodiversity index (D=0.918), Simpson's reciprocal index (1/D=1.088), Simpson's evenness index (E-1/D=0.068), species richness (S), Shannon-Weiner's index (H'=3.775), Menhinick's index (D-mn=0.804), and Margalef's index (D-mg=2.510)] were calculated for the stream. The physicochemical parameters [temperature (23.125 +/- 3.514 degrees C), dissolved Oxygen (9.003 +/- 0.627 mg L-1), pH (7.333 +/- 0.201), turbidity (76.5 +/- 6.403 NTU), electric conductivity (201.68 +/- 11.31 mu s cm(-1)), free CO2 (124.75 +/- 9.912 ppm), total dissolved solids (126.1 +/- 9.477 ppm), total alkalinity (4.325 +/- 0.171 mg L-1), total suspended solids (127.1 +/- 6.864 ppm), total hardness (5.225 +/- 0.341 mg L-1), salinity (42.25 +/- 6.292 ppt), calcium hardness (2.975 +/- 0.670 mg L-1), magnesium hardness (105 +/- 9.954 mg L-1), potassium (0.0145 +/- 0.001 mg L-1), sodium (16.55 +/- 3.861 mg L-1), chloride (1.825 +/- 0.727 mg L-1), and nitrate (0.053 +/- 0.006 mg L-1) level] were monitored and found to be in varying but permissible ranges. The stream was found to be harboring a number of economically valuable fish species. An exotic fish species, C. carpio, was found well flourished, indicating the potential of the stream to be used for mitigating the declining ichthyofaunal diversity in the main nearby rivers. Two species, P. sophore and P. ticto, were recorded for the first time from the district. Proper management, appropriate fish stocking, and implementing environmental/fishing laws are suggested for the maintenance of the diversity and alleviating anthropogenic stress/threats.