Halloween Urchin (Tripneustes gratilla) saltwater invertebrate

Halloween Urchins are colorful collector urchins that can reach a substantial adult size and continuously graze hard surfaces. They are generally coral safe but may carry or dislodge unsecured frags, shells, and rubble. Provide a mature aquarium with broad grazing area, stable salinity, strong oxygenation, and enough room for growth. Their spines and tube feet should never be pulled during handling, and copper is toxic.

Offer dried seaweed, algae sheets, or herbivore wafers when natural algae is insufficient. Larger collector urchins can clear a limited rock area quickly, so plan supplemental feeding before the tank becomes bare.

Film Algae Turf Algae Macroalgae Dried Seaweed
A peaceful, mobile grazer with normal covering behavior. It may decorate itself with loose material and can move lightweight objects while foraging.

FAQ

Frequently Asked Questions

About the Halloween Collector Urchin

  • How large does a Halloween Urchin get?
    Collector urchins can become several inches across, so provide generous open grazing space.
  • Is it reef safe?
    It is generally coral safe, but secure loose frags and décor.
  • Why is it carrying objects?
    Covering is normal behavior used by collector urchins.
  • What should I feed it?
    Feed dried seaweed or algae-based food when the aquarium cannot supply enough natural growth.