SELECTIVE SKELETAL FATTY-ACID DEPLETION IN SPAWNING PACIFIC PINK SALMON, ONCORHYNCHUS-GORBUSCHA

Polyunsaturated fatty acids (PUFA) of the skeletal triacyglycerols of Pacific pink salmon, Oncorhynchus gorbuscha, are preferentially depleted during spawning migration. The vertebral centra (VC) triacyglycerol fatty acids of ocean prespawners are comprised of 24% w/w PUFA (mostly 20:5n-3 and 22:6n-3), whereas those of post-spawners contain only 9%. There is also an increase in the relative amounts of C-20 and C-22 monounsaturated fatty acids. The VC triacylglycerols of ocean prespawners contain 8% 20:1 and 22:1 fatty acids, which rises to 21% in river post-spawners. Neurocranial (NC) triacylglycerol fatty acids follow a similar pattern, as do those in phospholipid. The skeletal triacylglycerol and phospholipid fatty acids of ocean prespawning sockeye, O. nerka, chum, O. keta, and coho salmon, O. kisutch, do not differ substantially from those of prespawning pink salmon.