Unravelinghabitat use of Coilia nasus from Qiantang River of China by otolith microchemistry

The habitat use and life history characteristics of the estuarine tapertail anchovy, Coilia nasus from Qiantang River were studied by examining the environmental signatures of Sr and Ca in otoliths using otolith microchemical analysis. The results indicate the C. nasus in the present study could be briefly divided into three types: Types 1/Type 2 of riverine origin and initial relative long-term/short-term freshwater residence, and Types 3 of estuarine origin and initial brackish early life history. The availability and fluctuation of certain levels of Sr:Ca ratios (i.e., Sr:Ca×1000) between salinity scale of 3.00 and 7.00 reveal that the C. nasus analyzed in this study spent much more time in brackish habitat of the river's estuary. This study has established that the C. nasus of Qiantang River Estuary has a diverse and complex pattern of life history and habitat use which makes their life history and migration pattern vary from those of the Yangtze River.