Localization of a marine source of odd chain-length fatty acids. I. The amphipod Pontoporeia femorata (Kröyer).

The amphipod Pontoporeia femorata (Kröyer) contains approximately equal amounts of odd chain length and even chain length fatty acids. Mature males of this species are released into the waters of Jeddore Harbour during winter months as the result of a regular reproductive cycle and become food for smelt Osmerus mordax moving into the harbor in preparation for spring spawning runs, thus accounting for the previously reported unusual fatty acid composition of these smelt. The exceptionally high levels of odd chain length fatty acids in P. femorata occur at all stages of maturity in both sexes of the animal and are found in P. femorata in other locations.