---
title: Pustulose Phyllidiella (Phyllidiella pustulosa)
scientific_name: Phyllidiella pustulosa
common_name: Pustulose Phyllidiella
taxon: Nudibranch
published: 2024-08-31T18:53:45.073Z
updated: 2026-08-14T13:48:20.390Z
tags: Pustulose Phyllidiella, Phyllidiella pustulosa, Nudibranch, Red Sea, Marine Life, Diving
url: https://redseacreatures.com/taxon/invertebrate/molluscs/nudibranch/pustulose-phyllidiella
---

# Pustulose Phyllidiella (*Phyllidiella pustulosa*)

## Quick facts

- **Group:** Nudibranch (*Nudibranchia*)
- **Size:** up to 6 cm
- **Depth:** 2-30 m
- **Diet:** Spongivore
- **Activity:** Nocturnal
- **Rarity:** Common
- **Habitat:** Reef and rubble with encrusting sponges
- **Reproduction:** Egg layer, Simultaneous hermaphrodite
- **Hazard:** Poisonous

## How to recognise it

- black body covered in clusters of pink-gray tubercles
- no visible gills on the back at all
- hard, rubbery texture, unlike the soft chromodorids
- length up to 6 cm

A black slug covered in clusters of pink knobs, six centimeters (2.4 in), moving slowly over rubble in the open. It looks nothing like the soft, frilly nudibranchs beside it, and it is built on a different plan.

There are no gills on its back. The phyllidiids gave them up and breathe through folds tucked under the mantle edge instead, which leaves the whole upper surface free to be armor - hard, rubbery and studded with tubercles.

What fills those tubercles is the point. This animal eats sponges and stores their sesquiterpenes at the surface, and it will release them into the water when it is disturbed. In the open sea that is nothing; in a bucket or a tank it is lethal. Phyllidiids are notorious among aquarists for exactly this - one stressed slug can kill everything in a closed volume, itself included.

On the reef the rule is simply to look. The pattern varies enough between individuals that several species were long confused with this one, and the reliable characters are the shape of the tubercle clusters and the color of the rhinophores.

## Also known as

- **English:** pustular phyllidia, Warty Wart Slug, pustule nudibranch, pustulose wart slug
- **French:** Phyllidie pustuleuse
- **Italian:** Fillidiella pustolosa
- **German:** Pustel-Warzenschnecke
- **Dutch:** Pokken Wratslak
- **Japanese:** コイボウミウシ
- **Chinese:** 突丘小葉海蛞蝓, 突丘葉海牛, 突丘葉海麒麟
- **Russian:** Филлидиелла пузырчатая
- **KO:** 혹투성이갯민숭이
- **TH:** ทากเปลือยปุ่มดำขาว

## Scientific synonyms

- *Fryeria variabilis* Collingwood, 1881
- *Phyllidia melanocera* Yonow, 1986
- *Phyllidia nobilis* Bergh, 1869
- *Phyllidia nobilis var. rotunda* Eliot, 1904
- *Phyllidia pustulosa* Cuvier, 1804
- *Phyllidia rotunda* Eliot, 1904
- *Phyllidia spectabilis* Collingwood, 1881
- *Phyllidia verrucosa* van Hasselt, 1824
- *Phyllidiella nobilis* (Bergh, 1869)

## Range

Mozambique, New Zealand

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*Source: [Red Sea Creatures](https://redseacreatures.com/taxon/invertebrate/molluscs/nudibranch/pustulose-phyllidiella)*
*Updated: August 14, 2026*