Species Abundance and Environmental Association of Nemacheilidae in South-Central Bhutan

Abstract

Nemacheilids are distributed mainly in the South–central regions of Bhutan and shown that environmental variables have significant effect on their distribution, abundance and diversity. However, existing knowledge and research on Nemacheilids association with its environment is limited in Bhutan. Nemacheilids abundance in South–central Bhutan were assessed and associated with environmental variables. The study was surveyed from the three major basins; Punatsangchhu, Mangde chhu and Amochhu basins which comprised of Dagana, Sarpang, Tsirang, Samtse and Trongsa Districts. Total of 56 sites were surveyed using simple random sampling from which Nemacheilids were found in only 22 sites. Eleven species were identified in three genera. Canonical correlation analysis (CCA) was used to assess the association between species abundance and eleven environmental variables.  Elevation and temperature were the most influential variables followed by total hardness, electrical conductivity, turbidity, pH, total dissolved solids, salinity, ammonia, dissolved oxygen and chloride with lesser importance. It is recommended to explore additional variables, sites and anthropogenic activities to further elucidate the dynamics of Nemacheilids abundance and formulate effective conservation strategies.