Red Pincushion Urchin (Echinometra sp.)
The Red Pincushion Urchin (Echinometra sp.) is an attractive marine algae grazer recognised by its rounded body and dense covering of red, burgundy or reddish-brown spines. Also sold as a Red-Spined Urchin or Rock-Boring Urchin, it spends much of its time moving across live rock and aquarium surfaces in search of algae, biofilm and organic material. This useful clean-up crew animal can help control nuisance algae in a mature marine aquarium, although it may also remove coralline algae and dislodge unsecured corals or decorations while grazing.
Common Names
- Red Pincushion Urchin
- Red-Spined Urchin
- Red Rock-Boring Urchin
- Rock-Boring Urchin
Key Features
| Feature | Description |
|---|---|
| Body Shape | Rounded |
| Spine Color | Red, burgundy, or reddish-brown |
| Behavior | Active grazer on live rock and surfaces |
| Algae Control | Effective against nuisance algae; may remove coralline algae |
FAQ
What types of algae does the Red Pincushion Urchin eat?
The Red Pincushion Urchin feeds on various types of algae, including nuisance algae and biofilm. It may also consume coralline algae, though this can lead to unintended removal of attached corals or decorations.
Is this species safe for use in a reef aquarium?
While it helps control algae, the Red Pincushion Urchin may dislodge unsecured corals or decorations due to its grazing behavior. It is best suited for non-reef or semi-reef setups where such risks are managed.
How does the Red Pincushion Urchin move around the tank?
It moves slowly across live rock and aquarium surfaces using its body and spines, searching for algae and organic material to graze upon.

Sonia Stewart –
Great for keeping algae under control in a mixed marine tank. It moves around the live rock and eats down on green algae. I noticed it occasionally bumped a small coral, so I’ve added some secure placements. Still, it’s a useful addition to my system.
Paul Parr –
This urchin has been active for several months and consistently reduces algae buildup. The red spines stand out and it looks very natural in the tank. I’ve kept it in a non-reef setup where it’s safe to graze.
Piers Tucker –
Helpful for algae, but it did remove a small piece of coralline algae that was attached to a rock. I’ve since moved it to a corner with less sensitive areas. Overall, it’s a decent clean-up crew.