Blue-green pigmented symbionts of echiurids from polar marine environments.

Burrowing echiurid worms from marine sediments including sulfidic habitats of both the Antarctic Ocean and the Norwegian Sea were partly colonized by blue-green prokaryotic symbionts. These resembled free-living Prochlorophytes and contained 2-vinylpheophorbide-a5 as the only pigment being detectable by HPLC. The potential biogeochemical significance of these epizoic symbionts is discussed.