Ecology of Chaetognaths in the Hooghly Estuary, Bay of Bengal

Abstract

Occurrence, abundance and seasonal fluctuations of chaetognaths (Sagitta bedoti and S. enflata) in the lower stretch of Hooghly estuarine system are studied in relation to environmental parameters at 3 stations in and around Sagar Island during March 1979 to February 1981. Chaetognaths constitute an immigrant fauna from the sea to the estuary and salinity appears to be the major factor controlling their distribution in this estuarine system. At one station close to the mouth where annual variations in salinity are relatively less, they are found throughout the year, with maximum abundance during June/July. Chaetognaths are either absent or very poorly represented in other 2 stations during the late monsoon period.