---
title: Urchin Mantis Shrimp (Echinosquilla guerinii)
scientific_name: Echinosquilla guerinii
common_name: Urchin Mantis Shrimp
taxon: Mantis shrimp
published: 2026-08-06T11:09:24.460Z
updated: 2026-08-08T16:04:59.695Z
tags: Urchin Mantis Shrimp, Echinosquilla guerinii, Mantis shrimp, Red Sea, Marine Life, Diving
url: https://redseacreatures.com/taxon/invertebrate/crustaceans/mantis-shrimp/urchin-mantis-shrimp
---

# Urchin Mantis Shrimp (*Echinosquilla guerinii*)

## Quick facts

- **Group:** Mantis shrimp (*Stomatopoda*)
- **Size:** up to 12 cm
- **Depth:** 1-25 m
- **Diet:** Carnivore
- **Activity:** Nocturnal
- **Rarity:** Rare
- **Habitat:** Burrows in coral rock and rubble

## How to recognise it

- tail plate covered in radiating spines like a sea urchin
- reddish brown body
- plugs the burrow entrance with its spiny tail
- length up to 12 cm

A reddish brown mantis shrimp to about 12 cm (5 in) with a tail plate unlike anything else in the group: a domed disc covered in stout radiating spines, so close to a small sea urchin that the resemblance is the whole point. The animal backs into its burrow and seals the entrance with it, leaving a predator facing what looks like a spiny urchin wedged in a hole.

Using part of the body as a door has a name - phragmosis - and it turns up independently in ants, frogs and lizards, but among crustaceans this species is the striking example. It occupies burrows in coral rock and rubble from about 1 m to 25 m (3 to 80 ft), hunting near the entrance after dark and retreating tail-first at any disturbance. That habit is exactly why it is so rarely seen: a diver passing in daylight sees a spiny plug, not an animal, and reads it as one more urchin among thousands. Anyone who finds one out in the open at night has had a genuinely lucky dive.

## Also known as

- **English:** Urchin-tail Mantis Shrimp
- **Japanese:** ウニシャコ
- **Russian:** Ежовый рак-богомол

## Scientific synonyms

- *Gonodactylus guerinii* White, 1861

## Range

Indian Ocean, New Caledonian Exclusive Economic Zone, Seychelles, South Pacific Ocean

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*Source: [Red Sea Creatures](https://redseacreatures.com/taxon/invertebrate/crustaceans/mantis-shrimp/urchin-mantis-shrimp)*
*Updated: August 8, 2026*