Eastern Pencil Urchin

Phyllacanthus parvispinus

The Eastern pencil urchin has a distinctive appearance characterized by its long, slender spines. These spines can vary in color, typically blending with their surroundings, which helps them avoid predators. This species is found primarily in shallow reef environments, thriving in the subtropical waters of the Southwest Pacific, particularly around Australia and the Kermadec Islands. Divers may encounter this urchin at depths generally shallower than 40 meters, with most sightings occurring in even shallower waters. Feeding primarily on algae, the Eastern pencil urchin plays a role in maintaining the health of its reef habitat. Its diet consists mainly of various types of algae, which it grazes from the substrate. Reproduction occurs through external fertilization, with the species being gonochoric. The fertilized eggs develop into planktonic larvae, which eventually settle on the ocean floor and metamorphose into juvenile urchins. When diving, encountering the Eastern pencil urchin can be a subtle experience, as they often blend into their environment. Divers should take care not to disturb them, as they are harmless to humans. Observing their feeding behavior can provide insight into their role in the ecosystem. The conservation status of this species is currently not evaluated, indicating that there is insufficient data to assess its population trends.