White Sea Urchin

Lytechinus pictus

Lytechinus pictus, commonly known as the white sea urchin, is a small sea urchin that can reach a diameter of up to 40 mm. Its coloration typically ranges from greyish or pale straw brown, sometimes exhibiting a pinkish hue. The spines are robust, short, and blunt, with the basal half usually white and the upper portion varying in color. Juvenile specimens may display banded spines, which can help distinguish them from other species in the area. This species is often found in shallow reefs across the tropical and subtropical eastern Pacific Ocean, with its range extending from central California down to Ecuador, typically inhabiting depths of up to 300 m, although most occurrences are shallower than 40 m. In California, it is commonly found in the middle and lower intertidal zones and often forms dense aggregations near kelp beds, where it can reach densities of up to 80 individuals per square meter. The white sea urchin primarily feeds on algae, particularly young stages of kelp species such as Macrocystis, Gigartina, and Laminaria. It is more active at night, often semi-burying itself in sand during the day and camouflaging with shell fragments and gravel. Reproduction involves external fertilization, with embryos developing into planktotrophic larvae before settling to the bottom to metamorphose into young urchins. Encounters with this species while diving may reveal them in large groups, particularly around kelp forests, where they play a role in the local ecosystem as grazers. The conservation status of Lytechinus pictus is currently listed as Not Evaluated.