---
title: Burrowing Urchin (Echinometra mathaei)
scientific_name: Echinometra mathaei
common_name: Burrowing Urchin
taxon: Sea urchin
published: 2023-12-29T09:23:35.800Z
updated: 2026-08-15T18:57:08.484Z
tags: Burrowing Urchin, Echinometra mathaei, Sea urchin, Red Sea, Marine Life, Diving
url: https://redseacreatures.com/taxon/invertebrate/echinoderms/sea-urchin/burrowing-urchin
---

# Burrowing Urchin (*Echinometra mathaei*)

## Quick facts

- **Group:** Sea urchin (*Echinoidea*)
- **Size:** up to 8 cm
- **Depth:** 0-20 m
- **Diet:** Herbivore
- **Activity:** Nocturnal
- **Rarity:** Common
- **Habitat:** Shallow reef rock and rubble, each animal in its own burrow
- **Reproduction:** Broadcast spawner, Gonochoric
- **Hazard:** Venomous

## How to recognise it

- short stout spines, usually purple-brown with pale tips
- oval rather than round outline
- sits in a socket in the rock that fits it exactly
- test up to 8 cm across

The urchin that eats rock. It settles on limestone as a juvenile and starts grinding - with its spines and with the five teeth of its jaw apparatus - until it sits in a socket that fits its own body, and it can spend years in that one hole, leaving only to graze the algae within reach and returning to the same spot.

The effect at scale is enormous. Dense populations of boring urchins remove kilograms of limestone per square meter per year, and on shallow reefs they are among the main agents of bioerosion - the process that turns reef rock back into sand. Where predators that eat urchins are fished out, the population explodes and the reef erodes faster than it grows.

The jaw apparatus is worth knowing on its own: five teeth arranged in a lantern-shaped frame, self-sharpening, and strong enough to work stone. Aristotle described it, and the structure still carries his name.

Spines are sharp and break off in the wound. The sting is minor by urchin standards, but a hand pushed into a shallow crevice usually finds one of these before it finds anything else.

## Also known as

- **English:** rock-boring urchin, Indo-Pacific Rock-boring Urchin, Burrowing Urchin
- **Hebrew:** סגלגלית שוניות
- **French:** Oursin de roche, Oursin perforant
- **Italian:** Riccio scavatore indo-pacifico
- **German:** Matheus' Seeigel
- **Portuguese:** Ouriço-do-mar-corrosivo
- **Czech:** ježovka Mathaeova
- **Japanese:** Hon-nagauni, ナガウニ
- **Chinese:** 梅氏長海膽
- **Russian:** Морской еж - скаловерт
- **KO:** 만두성게
- **TH:** เม่นหนามเขียว

## Scientific synonyms

- *Echinometra brunea* A. Agassiz, 1864
- *Echinometra heteropora* L. Agassiz in L. Agassiz & Desor, 1846
- *Echinometra megastoma* M'Clelland, 1840
- *Echinometra microtuberculata* A. Agassiz, 1863
- *Echinometra picta* A. Agassiz & H.L. Clark, 1907
- *Echinus mathaei* Blainville, 1825
- *Ellipsechinus decaryi* Lambert, 1933
- *Ellipsechinus matheyi*
- *Ellipsechinus pictus* (A. Agassiz & H.L. Clark, 1907)

## Range

Eastern Africa & Madagascar, Egypt, Federal Republic of Somalia, Indian Ocean, Kenya, Madagascar, Maldives, Mozambique, New Zealand, Philippines, Red Sea, Republic of Mauritius, Seychelles, South Africa, Tanzania, Western Indian Ocean

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*Source: [Red Sea Creatures](https://redseacreatures.com/taxon/invertebrate/echinoderms/sea-urchin/burrowing-urchin)*
*Updated: August 15, 2026*