Star Encrusting Sponge

Halisarca sp.

There are several species of star encrusting sponges that are so similar you need a microscopic examination to positively identify. Suffice it to say, if you said "I saw a Star Encrusting Sponge" it would be something like these. Look for them in recesses, under overhangs, and walls of dead coral structures and cave/rock walls.