Phyllacanthus imperialis is a large pencil urchin found most often wedged into ledges and small caves or in rock piles on the seaward reef. Obviously something preys upon them, since piles of loose spines from a deceased individual are commonly seen. Often the cap shell Hipponix prionocidaricola is found clinging to the spines.
Young specimen.
Underside.
Created 16 June 2018
Updated 27 April 2021