Observations in the Skin Pigment and Amoebocytes, and the Occurrence of Phenolases in the Coelomic Fluid ofHolothuria ForskaliDelle Chiaje

Abstract

The black body-wall pigment of Holothuria forskali shows the characteristics of melanin. From histological evidence it appears that the pigment is formed in association with the amoebocytes of the coelomic fluid, which eliminate the pigment in the body wall. The amoebocytes contain a phenolase system, distinct from the cytochromecytochrome oxidase system, with the properties of tyrosinase. The relation of these findings to those of a preceding and more complete investigation into melanogenesis in Diadema is discussed.