Variegated urchin (Lytechinus variegatus) care guide

Group
Other invertebrates
Other names
Green sea urchin, Variegated sea urchin, Pincushion urchin
Family
Toxopneustidae
Origin
Western Atlantic and Caribbean: North Carolina to Brazil, Gulf of Mexico; seagrass, rubble, sand and rocky reefs
Water
saltwater
Maximum size
11 cm
Care level
intermediate
Temperament
peaceful
Reef safe
with_caution

Care

The variegated urchin is a short-spined urchin with a rounded test up to about 11 cm across, densely covered in spines. The test may be purple, green or dull red blotched with white, and the spines are mostly short with a few longer ones, sometimes two-toned; a green test with green or white spines is the most common form in the Caribbean. It has white pedicellariae (tiny pincers), which separate it from the similar Lytechinus williamsi. Four subspecies are recognised. It lives in clear, shallow water on reefs, rubble, sand and seagrass beds, sometimes at densities of 15 per square metre. Like many urchins it 'decorates' itself, holding shells, algae and seagrass on its upper surface, probably to shade itself from strong light. Give it a mature tank with plenty of rock to graze and stable, normal reef conditions; urchins react badly to swings in salinity. Our sources give no water figures for this species. Losing spines is a sign of poor water quality. Clean-up role: it grazes film and hair algae and will strip rock surfaces, which can make it an excellent algae control animal, but it can also eat coralline algae and wanders around knocking over loose corals. Glue frags down. Copper: copper-based medicines and some plant fertilisers are toxic to shrimp, snails and most other invertebrates. Never dose them in a tank holding this animal, and check the label of any treatment or fertiliser before use. Sources: Wikipedia (en.wikipedia.org/wiki/Lytechinusvariegatus). Checked October 2026.

Diet

Mostly herbivorous: grazes algae and seagrass with its five-toothed jaw (Aristotle's lantern), and its tube feet catch drifting debris. In the tank it eats film and hair algae; supplement with dried seaweed (nori) and algae wafers when algae runs short, or it will starve.

Breeding

Separate sexes with external fertilisation: eggs and sperm are released into the water, and the planktonic pluteus larvae pass through several stages before settling. Timing varies by region; in Bermuda spawning is brief and linked to the moon. It is widely bred in laboratories, but larvae are rarely raised in home aquaria.

Compatibility and tank mates

Reef safe with caution: it does not eat corals, but it bulldozes loose frags, may pick up small corals as 'decoration' and grazes coralline algae. Peaceful with fish and other invertebrates. Eaten by triggers and large puffers. Handle carefully: the short spines can still puncture skin.

Last updated 8 October 2026. Community-edited care guide on Aquatic-Auctions.

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