The spotted salamander isn't a jailbird, but for a vertebrate it has an unusual cell mate nonetheless: algae.
For more than a century, scientists have known that a certain species of alga, Oophila amblystoma, grows in association with spotted salamanders' eggs. The alga's scientific name even means "egg-loving."
Earlier research had found that eggs developed faster in the presence of algae and that algae grew better in water that had contained embryos. But they didn't know the algae actually grew within the eggs.
In fact, this is the first time algae have been found living symbiotically within the cells of any vertebrate animal.
"It raises the possibility that more animal/algae symbioses exist that we are not aware of," said Indiana University at Bloomington biologist Roger Hangarter in a press release from that school. It is also nice to know that vertebrates can take photosynthetic advantage of plant life growing in their skin. Invertebrate animals, like nudibranchs, a.k.a. sea slugs, keep algae as cell mates and, like photovoltaic cells on a rooftop, utilize the energy they produce.