Molecular tools are allowing biologists to investigate more closely a a long-known symbiotic relationship between an algae and a most unusual partner, salamander eggs. As you know most amphibians lay their eggs in still water, and algae grow inside these salmander eggs making them green (the spotted salamander in N. America has eggs like this too). Metabolic waste products, carbon dioxide and nitrogenous compounds are raw materials for the algae and the photosynthesizers give off oxygen, thus the symbiosis. But how do the algae get there inside an egg? Algal genes in salamander DNA suggest the algae may be inherited, passed on from mom to offspring (assuming the algae go with the egg). Algae live inside lots of animals: hydra, mollusks, sea slugs, corals, but this is a vertebrate, a supposedly higher animal. And you know what that means? Green aliens are a complete possibility! Of course, Star Trek fans already knew about the slave women from Orion. What great slaves! So cheap to feed and clothe! HT to Thomas' Plant-Related Blog.