Hairy Pincushion Urchin

My species/animal is an invertebrate: Hairy Pincushion Urchin (Tripneustes gratilla). It is a peaceful species that is reef-safe with caution, admired for its rounded pincushion body, dense and somewhat “hairy” appearance due to fine spines, striking color variations (ranging from purple, brown, green to white), and excellent algae-grazing ability.

Males typically cannot be visually distinguished from females, as this species shows no external sexual dimorphism, while juveniles are smaller with shorter spines and less intense coloration. They reach about 4–6 inches in diameter (including spines) as adults and should be housed in aquariums of at least 55 gallons.

Provide ample live rock for grazing, a sand or rubble substrate, and stable aquascaping, as they may pick up shells, algae, or small debris to camouflage themselves. Maintain stable water parameters (salinity ~1.020–1.025, temp ~72–79 °F, pH ~8.1–8.4). A secure lid is recommended to prevent them from crawling into overflows or filter intakes.

Diet should consist of natural algae growth (macroalgae, film algae, and hair algae), supplemented with dried seaweed (nori), spirulina, and sinking herbivore pellets. In low-algae aquariums, regular supplementation is essential to prevent starvation. With proper care, this urchin makes a useful and unique addition to reef aquariums, both as an effective algae grazer and as a fascinating display invertebrate.

International Aquatics Quarantine & Guarantee: All fish are checked by marine vets, given a formalin bath, and held for 14 days in copper-treated systems. We feed Selcon-soaked food with Kanaplex and Metroplex during quarantine. Unless marked, all livestock comes with our 15-Day Guarantee. You will receive a video of your fish eating before shipment. On request, we also send photos/videos after arrival at IA. Some species are import-to-order (3-10 business days). Many common species are already cleared or near the end of QT.

Several species will be import-to-order and may take anywhere from 3-10 business days to secure. Once your fish is secured, you will be notified, and the quarantine process will then begin.