Based on two bottom trawl surveys conducted in autumn 2000 and 2001,a total of 1106 stomach samples of Bombay duck Harpadon nehereus between 23–278 mm fork length were collected and analyzed.The results show that Bombay duck prey items consisted of 11 groups or 32 species,of which Apogon lineatus,Leptochela gracilis,Acetes chinensis,and Euphausia pacifi ca were the dominant prey species.Ontogenetic variations were found in feeding habits and feeding activity of Bombay duck.Feeding activity was highest in fi sh smaller than 50 mm,lowest in fi sh between 50 and 99 mm,and then increased with increasing size thereafter.As Bombay duck size increased,fi sh prey increased in importance,whereas euphausiids and decapods decreased in importance.Different trophic guilds were observed in feeding habits across the examined size range.Bombay duck smaller than 50 mm were zooplanktivores,mainly feeding on zooplankton and fi sh larva;those between 50 and 149 mm were generalist predators,mainly feeding on pelagic shrimps,demersal shrimps and fi shes;and those larger than 150 mm were piscivores,mainly feeding on fi shes.
