White Ring Shortspine Urchin

Species/Animal: (Invertebrates) White Ring Shortspine Urchin (Echinometra mathaei)

Description:
The White Ring Shortspine Urchin is a peaceful species that is generally considered reef-safe with caution. It is admired for its distinctive short spines with pale or white ring patterns at their bases, compact body form, and active grazing behavior. This urchin is well known for its ability to control algae growth but may scrape coralline algae and potentially disturb fragile corals if not monitored.

Sexual Dimorphism:

• Males and females are externally indistinguishable, as with most sea urchins.

• Juveniles tend to have thinner, lighter-colored spines compared to adults, which are darker and sturdier.

Size & Tank Requirements:
They reach about 3–4 inches in diameter (including spines) and should be housed in aquariums of at least 50 gallons, as they require stable rockwork for grazing and safe hiding crevices.

Habitat Needs:
Provide live rock for grazing and shelter, as well as stable sandbed areas where the urchin can burrow slightly or anchor itself. Ensure aquascaping is secure, since they can wedge into rocks and push smaller corals or frags out of place. Stable water parameters are crucial:

• Salinity: 1.020–1.025

• Temperature: 72–79°F

• pH: 8.1–8.4

A lid is not required for jumping but can prevent accidental equipment dislodging caused by their movement.

Diet:
This urchin primarily feeds on algae, coralline algae, and biofilm, making it a valuable part of a clean-up crew. In captivity, their diet can be supplemented with nori sheets, spirulina, macroalgae, and sinking algae pellets. If natural algae growth is low, additional feeding is necessary.

Care Note:
The White Ring Shortspine Urchin is hardy and effective at algae control but may consume coralline algae and disturb fragile coral placements. With proper care, it makes a fascinating and functional addition to marine aquariums.

algae, etc.], and with proper care this fish makes a standout addition to the aquarium.

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.