THE OCCURRENCE AND SIGNIFICANCE OF ENDOSYMBIOTIC CHLOROPLASTS IN THE DIGESTIVE GLANDS OF HERBIVOROUS OPISTHOBRANCHS1

Abstract

Intact algal chloroplasts were found in the digestive glands of 5 species of Opisthobranchia belonging to the order Saccoglossa. Preliminary studies on 3 of these confirm their endosymbiotic nature. The occurrence of these endosymbiotic organelles may be widespread among related species of Saccoglossa. Their independent functional existence supports the view that chloroplasts possess a system of nonchromosomal inheritance.