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
- Diet
- Herbivore
- 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
The rock-boring urchin is a hardy algae grazer for the rockwork of a saltwater tank. It is easy to keep.
Did you know
The rock-boring urchin can slowly excavate a burrow into solid limestone rock. It grinds away with its spines and teeth until it has a hollow that fits its body.
Caring for the rock-boring urchin
Give the rock-boring urchin a tank of at least 20 gal (75 L) with plenty of rock and algae to graze. Keep the water at 72 to 81°F (22 to 27°C) and a pH of 8.1 to 8.4.
It eats film algae, hair algae and coralline. If the tank runs low on natural growth, it will take nori or algae wafers.
The rock-boring urchin is peaceful and rated reef safe with caution. It is a strong grazer that can bulldoze loose frags and wedge into rockwork. Glue down corals and expect it to rearrange small pieces. There is no record of it breeding in home aquariums.
Good to know
Echinometra mathaei is a dark urchin of the family Echinometridae, with short, thick spines. Its colors run from near black to brown, green or reddish. Its jaw apparatus, called the Aristotle's lantern, lets it rasp both algae and rock.
In the wild
The rock-boring urchin is one of the most common reef urchins across the Indo-Pacific. It can occur in huge densities on some reefs, boring into reef rock and rubble in shallow, wave-washed water. By day it sits in a snug hollow in the rock, and at night it comes out to graze algae close to home.
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.
What does a rock-boring urchin eat?
A rock-boring urchin eats film algae, hair algae and coralline. If the tank runs low on natural growth, offer nori or algae wafers.
How big does a rock-boring urchin get?
An adult rock-boring urchin reaches about 3.1 in (8 cm).
Related species
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