The Pigmentation of Cavernicolous Animals

Abstract

1. The visible coloration of three species of amphipod Crustacea (Gammarus pulex, G. marinus and Orchestia gammarella) was found to be due almost exclusively to carotenoid pigments, including in each case a proportion of an astacin-like carotenoid acid. 2. No carotenoid pigments could be demonstrated, even in traces, in three species of the cavernicolous Amphipod genus Niphargus. 3. Carotenoid pigmentation is thought to be characteristic of Amphipoda and would therefore be the ancestral pigment of the cave forms. The lack of pigment in cave Amphipoda may be due to absence of light; it is not due to lack of carotenoid pigments in the food.