Diet Composition of Bullet Mackerel, Auxis rochei (Risso, 1810) in the Coastal Waters of Iloilo, Philippines

Abstract

The diet composition of bullet mackerel, Auxis rochei was studied using 200 specimenscollected from December 2013 to May 2014 in the coastal waters of Iloilo, Philippines. The size of A. rochei ranged from 11.1 to 31.2 cm in fork length (FL). A. rochei was epipelagic feeder that consumedmainly fishes. In addition, A. rochei consumed shrimps, copepods, crab larvae, amphipods andcephalopods. The diet also included small quantities of stomatopods, bivalves, and ostracods. Also,analysis of the prey-specific abundance against the frequency of occurrence shows that A. rochei havea narrow food niche, and are specialized feeder with fish as their dominant prey. Although fishes werethe primary in food consumed by all size class. The fishes gradually increased with body size.