69.1 Friday, Jan. 6 Chlorophyll synthesis in the photosynthetic sea slug Elysia clarki MIDDLEBROOKS, M.L.*; PIERCE, S.K.; BELL, S.S.; Univ. of South Florida; Univ. of South Florida; Univ. of South Florida firstname.lastname@example.org
Several species of sacoglossan sea slugs are able to photosynthesize using chloroplasts from the algae they feed upon sequestered inside of their digestive cells. The duration of photosynthesis varies greatly between species, lasting from several hours up to at least 9 months. In most cases, the sequestered plastids eventually stop functioning and slugs must feed again in order for photosynthesis to continue. Some sacoglossan species employ morphological adaptations for shading or behavioral responses to strong light to prolong the duration of their stolen plastids. However, Elysia chlorotica synthesizes chlorophyll which aids in preserving the longevity of their sequestered chloroplasts. Here we demonstrate that another sacoglossan, E. clarki, is also able to synthesize chlorophyll. However, after 3 months of starvation E. clarki the synthesis stops. The timing corresponds with a significant reduction in photosynthetic rates in starved slugs and a loss of plastids, although it is still unclear why E. clarki loses the ability to synthesize chlorophyll.