The Enchanted Braid

Book excerpt: A phenomenon of both awesome beauty and vital importance, the coral reef is home to the most diverse range of species of any environment on the planet, including fish, shrimps, worms, snails, crabs, sea cucumbers, sea stars, urchins, anemones, and sea squirts. The crux of reef life, scientists have discovered, lies in nature's most intimate example of symbiosis: the mutually beneficial relationship between the coral polyp and its "tenant," the zooxanthellate algae. Davidson's history begins with this deceptively diminutive hybrid, the engine behind the construction of the limestone-based coral structure.