Pincushion Urchin Care Guide for Reef Aquariums
The Pincushion Urchin is a hardworking, reef-safe cleanup crew member that can add personality and utility to your saltwater aquarium. With its rounded body covered in short, stiff spines, this urchin is a fantastic algae grazer and a fun invertebrate to observe after lights out.
Basic Care: Tank Requirements & Compatibility
Pincushion Urchins are generally hardy, but they do best in mature, stable reef systems. They roam constantly in search of algae and film on rocks, glass, and equipment.
- Minimum tank size: 30 gallons or larger
- Temperature: 72–78°F (22–26°C)
- Salinity: 1.024–1.026 specific gravity
- pH: 8.1–8.4
- Reef-safe: Yes, with caution around unsecured items
They are peaceful and can be kept with most reef-safe fish, shrimp, snails, and corals. Avoid housing them with aggressive predators such as triggerfish or large wrasses that may nip at their spines.
Tip: Make sure your live rock is firmly stacked. Pincushion Urchins are surprisingly strong and can dislodge loose pieces while grazing.
Diet, Behavior & Algae Control
The Pincushion Urchin is valued for its appetite for nuisance algae. It will consume various types of microalgae and film algae, helping to keep rockwork and glass cleaner between manual maintenance sessions.
- Primary diet: film algae, coralline algae, and other natural growths
- Supplemental foods: dried seaweed (nori), algae wafers, and sinking pellets
- Feeding frequency: offer supplemental food a few times per week if algae is limited
These urchins are mostly nocturnal, becoming more active after lights go out. One amusing trait is their tendency to “decorate” themselves. They may carry small shells, bits of macroalgae, or even frags plugs and loose equipment on their spines, so secure anything you don’t want them to move.
Care Tips: Acclimation, Handling & Long-Term Health
Like many invertebrates, the Pincushion Urchin is sensitive to sudden changes in salinity and temperature. Slow acclimation is essential to avoid stress and ensure a smooth transition into your reef tank.
- Acclimation: Use a drip method for at least 45–60 minutes.
- Handling: Avoid direct skin contact with spines; use a container or gloved hands.
- Water quality: Maintain low nitrate and phosphate levels with regular water changes.
- Calcium & alkalinity: Stable levels support healthy spine and test (shell) growth.
If you notice fading color, broken spines, or lack of movement, test your water parameters immediately. Poor water quality or sudden swings are the most common causes of health issues in urchins.
Is a Pincushion Urchin Right for Your Reef?
If you have a mature system with plenty of live rock and are looking for a natural solution to algae control, a Pincushion Urchin can be an excellent addition. Just be prepared for its habit of rearranging unsecured items and make sure you’re able to supplement its diet as your tank becomes cleaner.
For more invertebrate care resources, check out our guides on building a balanced clean-up crew and choosing reef-safe invertebrates. You can also learn about algae control strategies to complement the work of your Pincushion Urchin.