Diadema setosum
One of the most interesting creatures in our tank is the Black Needle Urchin. Native to the Indo-Pacific region, these odd, spiky beings are usually found in large groups that move together in lagoons or bays. They have tubed feet to walk around in the sand, or have been known to hitch rides on the backs of crabs. Often, small fish hide within the spins of the Black Needle Urchins for protection from other predators.
Black Needle Urchins eat dead fish, invertebrates and often living sponges and use powerful jaws to grind their food. These urchins are venomous and can shoot venom through their spines for short distances.