• ALGAE
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• v.25 no.4
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• pp.217-227
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• 2010

During feeding on algal cytoplasm, some sacoglossans are known to keep the chloroplasts photosynthetically active for days to months in their digestive cells. Korean sacoglossan mollusks containing functional chloroplasts were screened using an in vivo chlorophyll fluorescence measuring system (pulse amplitude modulation, PAM). We collected six sacoglossans feeding on siphonous and siphonocladous green algae (Elysia atroviridis, E. nigrocapitata, E. ornata, Ercolania boodleae, Placida dendritica, Stiliger sp.) and one feeding on ceramiaceaen algae (Stiliger berghi) and performed feeding experiments using 37 algal species. Three species of Elysia showed strong photosynthetic activity for months. However, P. dendritica maintained functional chloroplasts only for several hours after feeding. E. boodleae, S. berghi, and Stiliger sp. showed no photosynthetic activity in any circumstances. Among all species, E. nigrocapitata was capable to tolerate the longest period of starvation for over 4 months. Four 'solar powered' sacoglossans bonded avidly to their specific algal food. Each species attached to and consumed only one algal species when several algae were given together. While they occasionally consumed other algae after prolonged starvation, they always reverted to their specific algae when available.