Toxopneustidae Sea Urchins have an internal skeleton (test) made of overlapping plates which form a globular shape. The outer shell of this family are covered with short moveable spines, with tiny pedicellariae (pincers) located between the spines. Some species have a toxic venom within these pincers which is used for defence.
As with all other Sea Urchins, the mouth of Toxopneustidae Sea Urchins contains a complex chewing apparatus consisting of 5 jaws, known as an Aristotle's Lantern.
Toxopneustidae Sea Urchins use their tube feet and movable spines to move and are found in various colours, including black, blue, green, orange, pink and green up to 15 cm in diameter.
The Toxopneustidae Sea Urchins are herbivorous grazers, feeding on algae, detritus and sea grasses. In turn they are preyed upon by fish, gastropods and sea stars.
Another unusual adaptation in this Family is the attaching of foreign objects on to the top (arboral) surface of the shell. These species use their pedicellariae (tiny pincers) to pick up, and hold onto, pieces of algae, coral rubble, human rubbish or shell fragments. These objects may help to provide camouflage, armor, or sun protection for the urchin.