Feeding Ecology of Anguilliform Leptocephali in the Pacific and Indian Oceans Examined By Isotopic and Fatty Acid Analyses

Leptocephali are unusual in many ways compared to other fish larvae, and their feeding ecology appears to be based on consuming particulate organic matter, such as marine snow, as their food source.  Sampling surveys for leptocephali in the Mascarene Ridge area of the western Indian Ocean and in the western South Pacific were used to examine the stable isotopic and fatty acid composition of different taxa and sizes of leptocephali.  Some variation was observed in the isotopic compositions among families or sizes of leptocephali, and fatty acid compositions showed that leptocephali fed on a diversity of items, including living microorganisms and organic matter which differ among species and sizes. These observations are consistent with leptocephali obtaining their nutrition from marine snow, which contains a variety of materials originating from phytoplankton exudates, colonizing bacterial and small organisms, and the coagulation of other loose particles.