Rock Boring Urchin Care Guide
Echinometra mathaei is a small Indo-Pacific urchin that bores into rock and coral. It grazes algae but its burrowing causes reef bioerosion.
Overview
Echinometra mathaei, the rock-boring urchin, is a small echinoid of the family Echinometridae from the Indo-Pacific. It is generally dark with short, stout spines that may be green and purple-tipped, and shows a characteristic pale ring at the base of each spine. It uses its spines and teeth to excavate hollows in rock, sheltering by day and grazing algae at night.
Taxonomy
- Class: Echinoidea
- Order: Camarodonta
- Family: Echinometridae
- Genus: Echinometra
- Scientific name: Echinometra mathaei (Blainville, 1825)
Habitat
The species occurs throughout the Indo-Pacific from Madagascar and the Red Sea to Hawaii, on tropical reefs at depths down to about 139 m. It digs into basaltic and calcareous rock, living in the hollows it creates.
Tank requirements
- Minimum tank volume: 80 L
- Temperature: 24–26 °C (75–79 °F)
- pH: 8.1–8.4
- Carbonate hardness (dKH): 8–11
- Specific gravity: 1.024–1.026
- Adult test diameter: about 5 cm
- Lifespan: roughly 3–5 years
Provide solid live rock with crevices and stable parameters; be aware the urchin may enlarge holes in softer rock over time.
Diet
Echinometra mathaei is herbivorous, emerging from its hollow at night to graze algae on the surrounding rock.
Compatibility
It is largely reef compatible as an algae grazer, but its boring behaviour can damage soft live rock and undermine rockwork, so it is best treated as reef-cautious. Avoid urchin predators such as triggerfish and pufferfish.
Ecological role
Through burrowing the species contributes significantly to bioerosion of coral reefs; where predators such as finfish and gastropods are reduced by fishing, urchin numbers and reef damage can increase.