White Urchin

Lytechinus variegatus

Also known as Variegated Urchin, Variegated Sea Urchin, Green Sea Urchin, Pincushion Urchin

SaltwaterInvertebrate

White Urchin (Lytechinus variegatus) — Hans Hillewaert · CC BY-SA 4.0

Care at a glance

Temperature: 72–81°F (22–27°C)
pH: 8.1–8.4
Adult size: 3.9 in (10 cm)
Minimum tank: 20 gal (75 L)
Temperament: Peaceful
Social behavior: Solitary
Swim level: Bottom
Difficulty: Easy
Breeding: Hard
Rarity: Common
Reef safe: Reef safe with caution
Origin: Tropical Western Atlantic, from North Carolina to Brazil
Family: Toxopneustidae

Overview

A ravenous, peaceful grazer that mows down tough rockwork algae as well as the film on the glass, which is exactly why it gets sold as cleanup crew. It is a heavy eater for its size, so start feeding nori once the tank is clean. Glue frags down, because it will pick up and carry off anything loose.

In the wild

Comes from the tropical western Atlantic, from North Carolina through the Caribbean and Gulf of Mexico to Brazil, where it can carpet seagrass meadows and shallow rock at more than a dozen animals per square meter. In the aquarium it needs generous rockwork with algae to graze and stable, mature water.

Good to know

Lytechinus variegatus is a regular urchin in the family Toxopneustidae with short spines in white, green, or reddish shades, reaching around 10 cm across. In the wild it feeds heavily on turtle grass, and it is one of the most studied urchins in marine biology.

Did you know

It habitually piles shells, bits of seagrass, and other debris on its back, and researchers think this works as sunscreen, shielding the urchin from the strong ultraviolet light of the clear shallows it favors.