Observations on the biology of tarpon, Megalops cyprinoides (Broussonet) (Pisces : Megalopidae), in the Sepik River, Northern Papua New Guinea

Abstract

M. cyprinoides was recorded in higher-order rivers, ox-bow lakes and other areas of permanent water and also on the floodplain, although this is not a preferred habitat. Juveniles enter the river in April to July and the fish return to the sea before they begin to mature. The smallest individual recorded was 103 mm, the largest 440 mm (standard length). Fat deposit index was low for the whole population and surplus energy is probably directed to growth and not stored. Condition and fat deposit index were both slightly, but significantly, lower during the dry season. Stomach contents showed that this species is a meso-predator, feeding mainly on small prawns, aquatic and terrestrial insects and small fish. No major seasonal changes in diet were evident.