Carotenoid fractionation in the plumose anemone Metridium

Abstract

1. 1. Several colour-variants of the Pacific Coast plumose anemose, Metridium senile fimbriatum,a nd the red form of the British species, M. senile senile, yielded astaxanthin esters as the preponderant carotenoid fraction stored in somatic or in gonadal tissues. 2. 2. White males assimilated no carotenoid from a protracted diet of finely divided salmon flesh, rich in astaxanthin. Nor did whole body of a large mature white male yield more than traces of astaxanthin or of any other carotenoid. 3. 3. Pacific Coast Metridium with white, red or various shades of brown somatic tissues stored in their gonads various concentrations ofcarotenoids, predominately esterified astaxanthin. Somatic tissues of coloured types, including red variants from Britain, likewise yield astaxanthin esters, mostly epiphasic, but with some ambiphasic, in systems of hexane + 95% methanol. 4. 4. Esters of zeaxanthin (or certainly of a neutral xanthophyll exhibiting zeaxanthin's spectral and partitional properties) were usually present, while minor amounts of unfamiliar ketone or hydroxyketones were of occasional incidence. 5. 5. The red specimens from Britain likewise yielded zeaxanthin and its esters, as well as occasional minor quantities of acidogenic carotenoid ester (or the free compound) different from astaxanthin. No carotenes were detected in either species. 6. 6. Metridium senile fimbriatum exhibits some similarities tom, and certain apparent differences from, its British relative, M. s. senile, with respect to the metabolic fractionation of dietary carotenoids.