Introduction

Research during recent years has revealed the importance to plants and animals of biochromes. Functions such as oxygen transport, the transfer of substances between the vascular system and the tissues, as well as animal colouration have long been recognized.

The pigments described in the present paper were extracted from two colour varieties of Isactinia olivacea collected at Island Bay, Wellington, from well illuminated and exposed rock pools. The rock pools receive both morning and afternoon sun and are situated between the low and high tide marks. The anemones are always covered with water and are sheltered from strong wave action by surrounding calcareous algae. Moreover, I. olivacea is well concealed in its natural habitat, as it is usually covered with stand and small stones, except for the oral disc. Tentacles surrounding the oral disc are of similar colour and appearance to adjacent sea weed, i.e. anemones living in rock pools in which olive-green algae predominate have olive-green tentacles, while those amongst brown sea weeds have brown tentacles. The young of the green variety do not change colour to brown when transferred to a rock pool where the brown animals are found, and vice versa. Many animals have been transferred for experimentation and after almost three years there was no change in coloration.