The Pigmentation of Cavernicolous Animals

Abstract

1. Organic detritus was examined from Chislehurst Cave and from the Postumia Grotte (north Italy). The origin of carotenoid material in the detritus was closely associated with the influence of underground rivers. In the Postumia Grotte, large quantities of carotenoid material were present in detritus swept in by the underground river and deposited in a pool. A smaller quantity was present in similar detritus which had been exposed to the air. Very little was found in airborne detritus at the mouth of the cave, exposed to the air, to light and to temperatures higher than those prevailing within the cave. No carotenoid pigments were found in sediment from a drip pool, which was not connected with the underground river. In Chislehurst Cave no carotenoid pigments could be detected in detritus exposed to the air. These observations indicate that the cave fauna must have some access to carotenoid pigments. 2. A carotene (apparently the β-compound) was found, together with free xanthophylls in the cave salamander Proteus. The distribution varied in different parts of the body. No carotenoids were detected in the cave amphipod Niphargus, taken from the drip pool mentioned above. 3. In the carotenoid materials of detritus, xanthophylls predominate. This has been observed by other workers in carotenoid pigments from peat associated with calcium carbonate. The absorption maxima of the xanthophyll isolated by these workers agree closely with the maxima found in the present investigation. 4. An unidentified red pigment with a powerful fluorescence was found in all the detritus samples studied. It was soluble in organic solvents and showed absorption maximum at 457 ± 2µµ in carbon disulphide.