Note: Also Ježovka štětinatá. The body around 8 cm with extremely long and hollow spines up to 30 cm. The spines are mildly venomous, can inflict a painful wound if the sharp spines puncture the skin, but does not pose a serious threat to humans. D. setosum differs from other Diadema with five, characteristic white dots that can be found on its body. Orange anal ring. Blue/ green spot markings on genital plates. Black Longspine Urchins are great algae eaters.