Food and Feeding of Brown-stage Eels of Anguilla Bicolor in the Bolgoda Estuary

Abstract

Live samples of brown- stage eels of Anguilla bicolor were collected from the Bolgoda Estuary. The samples were grouped as <30Omm, 300-400mm, 400- 500mm, 500-60Omm and >600mm total length. The stomachs were injected with 10% formalin and the contents examined. The food of eels was assessed by the volume displacement method and the frequency of occurrence method. Gastrosomatic index was determined and the number of empty stomachs were recorded. The similarity among the diets of different size groups and that at different seasons were also determined. The results indicate that Anguilla bicolor change its feeding habits markedly as it grows. They feed mainly on invertebrates when small and become more piscivorous as they grow. No seasonal variation in the feeding habits was observed. It was also observed that the fish did not feed at the same intensity throughout the year. A high feeding intensity occurred from August to December.