Rock-boring urchin
Echinometra mathaei
Also known as Burrowing Urchin, Rock Boring Sea Urchin, Oblong Sea Urchin, Short spine urchin
SaltwaterInvertebrate
Care at a glance
- Temperature
- 72–81°F
- 22–27°C
- pH
- 8.1–8.4
- Adult size
- 3.1 in
- 8 cm
- Minimum tank
- 20 gal
- 75 L
- Temperament
- Peaceful
- Social behavior
- Solitary
- Swim level
- Bottom
- Difficulty
- Easy
- Breeding
- No record
- Rarity
- Common
- Reef safe
- Reef safe with caution
- Family
- Echinometridae
- Origin
- Indo-Pacific, boring into reef rock and rubble in shallow, wave-washed water.
Overview
Give it a tank of 75 litres or more at 22 to 27 C and pH 8.1 to 8.4 with plenty of rock and algae to graze. It eats film algae, hair algae, and coralline, and will take nori or algae wafers if the tank runs low on natural growth. It is a strong grazer that can bulldoze loose frags and wedge into rockwork, so glue down corals and expect it to rearrange small pieces.
In the wild
This is a hardy dark urchin with short, thick spines and a test around 5 cm across. In the wild it grinds a snug hollow into rock and sits in it by day, coming out at night to graze algae close to home. Colors run from near black to brown, green, or reddish.
Good to know
Echinometra mathaei is one of the most common reef urchins across the Indo-Pacific and can occur in huge densities on some reefs. Its jaw apparatus, called the Aristotle's lantern, lets it rasp both algae and rock.
Did you know
It can slowly excavate a burrow into solid limestone rock, grinding away with its spines and teeth until it has a hollow that fits its body.
Common questions
What size tank does a Rock-boring urchin need?
A Rock-boring urchin needs at least 20 gal (75 L). It spends most of its time in the bottom.
What temperature and pH does a Rock-boring urchin need?
A Rock-boring urchin is comfortable at 72–81°F (22–27°C) with a pH of 8.1–8.4.
How big does a Rock-boring urchin get?
An adult Rock-boring urchin reaches about 3.1 in (8 cm).
Related species
3.1 in (8 cm)50 gal (190 L)72–81°F (22–27°C)Red slate pencil urchin
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3.1 in (8 cm) · 50 gal (190 L)
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