Mayfly Nymphs as Water Pollution Bioindicator

Abstract

the immature called naiads (nymphs). The sub imago is the early, reproductively immature  adult and the mature ones are imago. The  nymphal stage of mayflies is always aquatic  and they are dominant in life history stage.  Depends upon external factors such as  temperature, food availability and current  velocity the nymphs undergo a series of molts as they grow (Brittain and Sartori, 2003). Water  temperature is higher at summer season and  lower at winter season. The maximum pH value  recorded in the month of August (monsoon) and  minimum in the April (summer). The pH was  alkaline throughout study period. The maximum  values recorded in the month of summer and  winter. The high Do in summer attributed to  increase in temperature and duration of bright  sunlight. The maximum value recorded in the  month of December (winter) and absent in the  month of March (monsoon). The results showed  that nymphs of mayfly are abundant in the  month of March, April and May because of  suitable water conditions like temperature, pH  and DO. The lower number of nymphs observed  in month of July, August and September in rainy  season.