Biliverdin in the Eggs of Nereis fucata

Abstract

Nereis fucata (Savigny) is a polychaete worm living in the gastropod shells carried by the hermit-crab Eupagurus bernhardus (L.) at Plymouth. The heteronereis or breeding stage found with hermit-crabs during late February was found to contain apparently ripe, blue eggs in the cœlom. The eggs were removed by slitting the body-wall of fresh worms, rinsed in sea water to remove haemoglobin, and separated from cœlomic cells by repeated centrifuging. The pigments in the eggs were extracted into a methanol–sulphuric acid mixture (19 : 1), when a turquoise-blue solution was produced. A purple pigment remained in the eggs; the nature of this pigment is being investigated. The original blue colour of the eggs was apparently due to the mixture of the purple pigment and the turquoise extract. The turquoise solution was filtered through glass wool, diluted with an equal volume of water and shaken with chloroform. The chloroform layer became bluish-green. This was evaporated to dryness in vacuo, and the pigment redissolved in methanol. The absorption spectrum of this solution showed a sharp peak at 392 mµ and a broader peak at 650 mµ, with minimum absorption at 500 mµ. The addition of zinc acetate and iodine produced a brilliant pink fluorescence in ultra-violet light. When more iodine was added the fluorescence became green. The presence of biliverdin was confirmed by the production of a purple colour, with a spectral absorption maximum near 490 mµ, by the addition of concentrated nitric acid, and by the destruction of the blue-green pigment with concentrated sulphuric acid.