Tuxedo Sea Urchin, Mespilia Globulus, 2–3 Inch Marine Invertebrate Prized For Intense Algae Grazing, Particularly On Hair Algae

The Tuxedo Sea Urchin (Mespilia globulus) is a fascinating and functional invertebrate, prized in reef aquariums for both its unique appearance and its powerful algae-grazing abilities. Named for its distinctive “tuxedo-like” coloration, this urchin typically displays alternating bands of deep blue, black, and sometimes reddish tones across its rounded body, creating a striking contrast against the reef environment.

One of the most entertaining traits of the Tuxedo Urchin is its habit of decorating itself with bits of rubble, shells, or even loose coral fragments. Using its tube feet, it will pick up and carry these items on its back as a form of camouflage and protection. While this behavior is completely natural, it’s something aquarists should be aware of, as unsecured frags or small decorations may get relocated around the tank.

In terms of utility, Mespilia globulus is an excellent algae grazer, feeding on film algae, coralline algae, and various nuisance algae that can accumulate on rockwork and aquarium surfaces. Its constant grazing helps maintain a cleaner, healthier tank and reduces the need for manual algae control. Supplementing its diet with dried seaweed (nori) is recommended if natural algae becomes limited.

The Tuxedo Sea Urchin is generally reef-safe and peaceful, making it compatible with a wide range of tank mates. It thrives in stable, well-established aquariums with sufficient rockwork for grazing and exploration. Moderate water flow and stable parameters are key, particularly maintaining appropriate calcium and alkalinity levels to support its calcareous structure.

Reaching a size of around 2–3 inches in diameter, this urchin is well-suited for tanks of 30 gallons or larger. Care should be taken when handling, as its spines, while not highly venomous, can still cause irritation if touched. It’s also important to ensure that rock structures are secure, as urchins can inadvertently dislodge loose pieces while moving.

With its bold coloration, quirky behavior, and practical algae-eating role, the Tuxedo Sea Urchin is a standout addition to any reef aquarium—bringing both personality and purpose to your clean-up crew.