Wired reports that Florida scientists may have found a sea slug that photosynthesises.
Unlike other symbiotic critters like lichens, Elysia chlorotica appears to actually manufacture chlorophyll itself, having, the team supposes, incorporated genes from the algae it eats:
Some related slugs also engulf chloroplasts but E. chlorotica alone preserves the organelles in working order for a whole slug lifetime of nearly a year. The slug readily sucks the innards out of algal filaments whenever they’re available, but in good light, multiple meals aren’t essential. Scientists have shown that once a young slug has slurped its first chloroplast meal from one of its few favored species of Vaucheria algae, the slug does not have to eat again for the rest of its life. All it has to do is sunbathe.
But the chloroplasts need a continuous supply of chlorophyll and other compounds that get used up during photosynthesis. Back in their native algal cells, chloroplasts depended on algal cell nuclei for the fresh supplies. To function so long in exile, “chloroplasts might have taken a go-cup with them when they left the algae,” Pierce said.
There have been previous hints, however, that the chloroplasts in the slug don’t run on stored-up supplies alone. Starting in 2007, Pierce and his colleagues, as well as another team, found several photosynthesis-related genes in the slugs apparently lifted directly from the algae. Even unhatched sea slugs, which have never encountered algae, carry “algal” photosynthetic genes.
The findings are yet to be replicated, but if they are? Way cool. I, for one, welcome our new slithering-shrubbery overlords.