Pencil urchin
Eucidaris tribuloides
InvertebratesSaltwater
- Care level
- Easy
- Temperament
- Peaceful
- Reef safe
- With caution
- Recommended tank
- 200 L
- Maximum size
- 10 cm
- Temperature
- 24–27 °C
- pH
- 8–8.4
- Diet
- Omnivore
Care at a glance
The pencil urchin owes its name to its thick, blunt spines, which resemble pencils rather than needles. That makes it one of the few urchins you can handle without risk of a sting.
By day it hides in a crevice; at night it grazes algae and growth off the rock. It is less selective than other urchins and may also go for soft corals, polyps and even small snails, so in a well-stocked reef tank it remains a matter of watching closely.
Good to know
Related species
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Values are mainstream hobbyist guidance, not gospel — always watch what your own animals need.