Tuxedo urchin

Lore & Background

The tuxedo urchin can reach a diameter of up to 5 cm. It has radial symmetry and small spines up to 2 cm long, usually brown, red, or dark in color. Its body features ten vertical zones without spines that are vibrant blue/green and have a velvety texture. It inhabits shallow tropical waters in the Indo-Pacific, Indian Ocean, and the south west coast of the western Pacific and Japan, living in reefs, coral rubble, and seagrass beds at depths of 0–200 meters. During breeding season (July to September), it is found abundantly near the coast, but migrates slightly off the coast at other times. This species is a nocturnal grazer, feeding on organic material on structures or the sea floor. It hides in coral or rocks during the day. It agglutinates debris for camouflage, and in the pet trade, lack of debris is considered a sign of stress or sickness. It lives in symbiosis with crabs and can be parasitized by some gastropods. Reproduction is gonochoric, with external fertilization and brooding common; ocean acidification is expected to threaten its reproduction.

Reader's Guide

Mespilia globulus, the tuxedo urchin, is a small sea urchin reaching 5 cm in diameter, with spines up to 2 cm long. Its body has ten bare vertical zones of vibrant blue/green with a velvety texture. It inhabits shallow tropical reefs, coral rubble, and seagrass beds in the Indo-Pacific and Indian Ocean, at depths from 0 to 200 meters. The species is a nocturnal grazer, feeding on organic material on the sea floor or on structures. Its grazing significantly increases coral survival and growth, but high urchin density negatively affects urchin growth due to limited food. It uses debris for camouflage, and in the aquarium trade, a lack of debris indicates stress or illness. It lives symbiotically with crabs and may be parasitized by gastropods. Breeding occurs from July to September, with external fertilization and brooding. The species is popular in recreational aquariums for its colors and low maintenance, but the pet industry relies on wild-caught individuals, as captive breeding is rarely successful.

Did You Know?

• The specific name 'globulus' refers to a small ball or spherule, describing its shape.
• Its grazing significantly increases the survival and growth size of corals.
• In the pet industry, a tuxedo urchin not carrying debris is said to be stressed or sick.