Abundance and composition of the gut contents of orbiculate cardinal fish, <i>Sphaeramia orbicularis</i> (Apogonidae) in Palompon, Leyte

Abstract

The study was conducted to examine the gut contents of Sphaeramia orbicularis using specimens from catches of a sled trawl survey conducted from June 2011 to May 2012 in Palompon, Leyte. One hundred seventy-one fish specimens were categorized into six different size classes maintaining an interval of 1 cm: 1-1.9 cm, 2-2.9 cm, 3-3.9 cm, 4-4.9 cm, 5-5.9 cm, and 6-6.9 cm. The guts of the fish specimens were isolated and the contents were placed on a petri dish for identification and counting. Based on the observed percentages of chyme, the species consume a large amount of easily digested materials. The increasing number of prey items as size class increases revealed that the smaller fishes prey on smaller organisms while the larger ones prey on the larger counterpart, and thus smaller predators are a subset of larger predators. Apogonids displayed a generalist diet, consisting mostly of demersal plankton and benthic invertebrates.