"… Elysia chlorotica has the ability to run on solar power like a plant. This leaf-shaped, gaudy-green sea slug photosynthesizes using genes that have been stolen from the algae it eats. Found in Eastern Canada’s saltwater marshes, Elysia chlorotica only needs to feed once in its lifetime, separating only the chloroplasts from the algal cells it eats and storing them inside its guts. This means that after feeding on the algae, the slug will begin producing its own chlorophyll and may never need to eat again. With the right amount of sunlight, this pretty sea slug could spend its life soaking up the rays and cruising along the sea floor.
How exactly do you snarf up DNA from your food source? Sci blogger Carl Zimmer asked Mary Rumpho, the researcher who figured out all this chlorotastic madness out to begin with. The slugs don’t just passively let the photosynthesizing structures from the algae (called plastids) harness sunlight, he noted. Rumpho responded that researchers think that the DNA is eaten along with the chloroplasts into cells lining the slug’s digestive system. The digestive system then expands while the sea slug grows, and even branches right next to its reproductive bits.”