Damn this actually tingled my spine, I need a symbiote, hehe.
In 1888, a biologist called Henry Orr was collecting spotted salamander eggs from a small, swampy pool when he noticed that some of them were green. He wrote, “The internal membrane of each egg was coloured a uniform light green by the presence in the membrane of a large number of minute globular green Algae.” Orr decided that the eggs “present a remarkable case of symbiosis.” The salamanders and the algae co-existed in a mutually beneficial relationship.
Orr was right that the two species have formed a partnership, but he was wrong in one crucial regard. He thought that the algae (Oophila amblystomatis) simply hung around next to the salamander embryos in the same egg. They don’t. More than 120 years later, Ryan Kerney from Dalhousie University has found that the algae actually invade the cells of the growing embryo, becoming part of its body.
With algae inside them, the salamanders become solar-powered animals, capable of directly harnessing the energy of the sun in the style of plants.
The spotted salamander isn’t the only animal to form partnerships with algae. The emerald green sea slug steals the genes and photosynthetic factories from a type of algae that it eats. Coral reefs are built upon a partnership between corals – a type of animal – and algae that provide them with energy. Many other animals, from sponges to worms have developed similar alliances. But the spotted salamander is the only back-boned animal (vertebrate) to have done so.
Since Orr’s discovery, several scientists have teased apart the details of this relationship. With algae in their eggs, the salamanders are more likely to hatch, they do so earlier, and they’re bigger and more developed when they emerge. All of this depends on light – the algae need it to photosynthesise and provide nutrients and oxygen to the embryos. If the eggs are kept in darkness, they never accumulate algae. In return for their services, the algae feast upon the salmanaders’ waste; if they are presented with eggs that have no embryos inside them, they hardly grow.