Coral reefs are the rain forests of the oceans, teeming with a biological diversity that boggles the mind. Just how did such profusion of life come to thrive in crystal-clear—and thus nutrient poor—water? The question has eluded scientists since Charles Darwin took his famous voyage on the H.M.S. Beagle in the 1830s.
Now, a team of German and Jordanian researchers may have the answer to this so-called coral reef paradox: an abundance of sponges that dwell inside the nooks and crannies of reef interiors.