Most particularly the green turtle Chelonia mydas is an effective grazer. It is rather rare these days, however, owing to hunting. The urchin Diadema antillarum is also an effective grazier. Please see the section on coral reefs for information on the formation of bare overgrazed areas in the vicinity of patch reefs. It is a suspension feeder and greatly prized as food for humans.
Adults are hermaphroditic and spawn freely in the water.
Larvae are planktotrophic and settle on eel grass blades. Adult scallops swim by clapping the valves and forcing water through openings on either side of the hinge. A. irradians swims in a zig-zagging motion by ejecting water alternately through its two jets. Steven Stanley has speculated that the zig-zag motion allows it to negotiate more efficiently through eel grass blades. They are swash riders, and move up and down with the tide, in order to maintain position in sediment that is moist, but not turned over by wave action.