It's not quite like the alien xenomorph lurking inside a human host, but it's bizarre nonetheless. For the first time, photosynthetic algae have been found living inside the cells of a vertebrate. Algae inside the spotted salamander (Ambystoma maculatum) are living in symbiosis, providing additional oxygen to the cells as they do their photosynthetic "thing." It was thought to be impossible for such symbionts to live there because of vertebrates' active immune systems, and researchers still don't know why the rules don't apply in this case.
COMMENT: Nature is like the universe: not just stranger than we imagine, but stranger than we can imagine.