The carotenoids of the eggs and embryos of the sea urchin Strongylocentrotus purpuratus

The carotenoids of eggs and plutei of the sea urchin S. purpuratus have been investigated. The eggs contain five pigments. Echinenone and β-carotene together make up more than 90% of the total, but the proportions vary widely: in seven investigations the ratios of echinenone to β-carotene ranged from 1.6 to 10.9. No correlation was found with the time of spawning. Zeaxanthin constitutes 2–3% of the total; and a pigment tentatively identified as isocryptoxanthin, 3.5–5.5%. A small amount of the β-carotene, usually 1–2%, is isolated as an isomer, probably neo-β-carotene B. Traces of two other pigments are seen on the thin layer chromatogram, but have not been isolated or identified.The total carotenoid content of the eggs varies considerably. Ten females, which spawned on the same date, had egg carotenoid contents ranging from 0.19 to 0.38 mg (echinenone equivalents) per gram of protein, with an average of 0.27 mg.The plutei of S. purpuratus contain the same five pigments, and traces of the same two pigments, that occur in the eggs.The pigments have been investigated quantitatively as a function of time, and it has been shown that no reduction occurs during early development in the total amount of carotenoid present, and no significant change occurs from egg to pluteus in the percentages of the different carotenoids. The significance of the data with respect to the function of carotenoids in marine eggs and embryos is discussed.