Grooved brain corals (Diplora labryinthiformis) like this one are abundant in the Florida Keys at depths of twenty to forty feet. The small black and blue fish is a neon goby (Gobiosoma oceanops), a "cleaner fish" that eats parasites and other debris from the mouth, gills, and skin of larger fish. A diver that extends his hand slowly toward the neon goby will occasionally get a finger cleaning, says Chris Martens, professor of marine sciences. The pair of red spiral plumes to the left of the goby belong to a Christmas tree worm (Spirobranchus sp.), which burrows into living coral and extends its plumage to catch passing particles for food. Christmas tree worms are easily disturbed and notoriously difficult to photograph. Passing shadows or air bubbles from a diver's respirator can make the worm instantly retract into its burrow. Photo by Chris Martens. For more information about Martens' work, see "Charley and the Aquanauts."
