Experiments on Green Algae Coexistent with Zooxanthellae in Sea Anemones

Abstract

Along the Pacific coast of North America sea anemones of the genus Anthopleura are dominant intertidal coelenterates. They occur as solitary tide pool inhabitants (A . xanthogrammica) or as aggregations carpeting firm substrates (A. elegantissima). One of the unique features of these species is their invariable symbiotic association with unicellular Dinophyceae. These brown or yellow-brown algae, known as zooxanthellae, occur intracellularly in the gastrodermal tissues of the host anemone (Muscatine, 1961) .