Solar-powered salamander

Their eggs often contain single-celled green algae called Oophila amblystomatis. The salamanders lay the eggs in pools of water, and the algae colonise them within hours.

The embryos release waste material, which the algae feed on. In turn the algae photosynthesise and release oxygen, which the embryos take in.

A close examination of the eggs revealed that some of the algae were living within the embryos themselves, and in some cases were actually inside embryonic cells. That suggested the embryos weren’t just taking oxygen from the algae: they might be taking glucose too. In other words, the algae were acting as internal power stations, generating fuel for the salamanders.

http://www.newscientist.com/mobile/article/dn23090-zoologger-the-first-solarpowered-vertebrate.html