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 ۱۶ fish species were recorded, belonging to ۴ orders (Cypriniformes, Channiformes, Siluriformes and Mastacebilformes), and ۵ 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=۰.۹۱۸), Simpson’s reciprocal index (۱/D=۱.۰۸۸), Simpson’s evenness index (E۱/D=۰.۰۶۸), species richness (S), Shannon-Weiner’s index (H′=۳.۷۷۵), Menhinick’s index (Dmn=۰.۸۰۴), and Margalef’s index (Dmg=۲.۵۱۰)] were calculated for the stream. The physicochemical parameters [temperature (۲۳.۱۲۵±۳.۵۱۴℃), dissolved Oxygen (۹.۰۰۳±۰.۶۲۷ mg L-۱), pH (۷.۳۳۳±۰.۲۰۱), turbidity (۷۶.۵±۶.۴۰۳ NTU), electric conductivity (۲۰۱.۶۸±۱۱.۳۱ µs cm-۱), free CO۲ (۱۲۴.۷۵±۹.۹۱۲ ppm), total dissolved solids (۱۲۶.۱±۹.۴۷۷ ppm), total alkalinity (۴.۳۲۵±۰.۱۷۱ mg L-۱), total suspended solids (۱۲۷.۱±۶.۸۶۴ ppm), total hardness (۵.۲۲۵±۰.۳۴۱ mg L-۱), salinity (۴۲.۲۵±۶.۲۹۲ ppt), calcium hardness (۲.۹۷۵±۰.۶۷۰ mg L-۱), magnesium hardness (۱۰۵±۹.۹۵۴ mg L-۱), potassium (۰.۰۱۴۵±۰.۰۰۱ mg L-۱), sodium (۱۶.۵۵±۳.۸۶۱ mg L-۱), chloride (۱.۸۲۵±۰.۷۲۷ mg/l), and nitrate (۰.۰۵۳±۰.۰۰۶ mg L-۱) 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.

Keywords:

Dir lower , Pakistan , Fish diversity , Diversity indices , Water quality , Fish stocking