This photo site compiles remarkable cases of symbiosis between pairs of unrelated animals. The boxer crab is one of the most bizarre things I’ve ever seen. Each of the crab’s claws carries a small stinging sea anemone–for the crab to defend itself. In turn, presumably the anemone receives transport and food.
Then there is the goby shrimp relationship. In this video, the goby fish acts as a sentry at the burrow of the shrimp. The fish gets a home, and the shrimp gets warned of predators.
Here is a three-way symbiosis of ant, caterpillar, and acacia tree. The ant feeds on nectar from the caterpillar, which feeds on the acacia tree, while the ants protect the acacia from more severe predation.
And this dugong gets parasites cleaned off by two kinds of associated fishes.
It’s enough to remind us that all life, indeed, cooperates as much as we compete. Could we rewrite all of Darwin as The Survival of the Most Cooperative?