Green Sea Slug Is Part Animal, Part Plant

Some animals eats algae and incorporates the algae’s chlorophyll into its own body. According to Sidney K. Pierce of the University of South Florida in Tampa, the sea slug Elysia chlorotica no longer has to, because it has incorporated enough of the plant’s genes into its own DNA to manufacture chlorophyll in its own body!

The slugs can manufacture the most common form of chlorophyll, the green pigment in plants that captures energy from sunlight, Pierce reported January 7 at the annual meeting of the Society for Integrative and Comparative Biology. Pierce used a radioactive tracer to show that the slugs were making the pigment, called chlorophyll a, themselves and not simply relying on chlorophyll reserves stolen from the algae the slugs dine on.

“This could be a fusion of a plant and an animal — that’s just cool,” said invertebrate zoologist John Zardus of The Citadel in Charleston, S.C.

Microbes swap genes readily, but Zardus said he couldn’t think of another natural example of genes flowing between multicellular kingdoms.

It looks like the tree of life has some spots where it merges as well as branches. Link

(image credit: Nicholas E. Curtis and Ray Martinez)