---
title: Red-gilled Mudworm (Chloeia bistriata)
scientific_name: Chloeia bistriata
common_name: Red-gilled Mudworm
taxon: Fireworms
published: 2024-03-24T08:02:21.717Z
updated: 2026-08-15T22:33:02.786Z
tags: Red-gilled Mudworm, Chloeia bistriata, Fireworms, Red Sea, Marine Life, Diving
url: https://redseacreatures.com/taxon/invertebrate/worms/fireworms/red-gilled-mudworm
---

# Red-gilled Mudworm (*Chloeia bistriata*)

## Quick facts

- **Group:** Fireworms (*Amphinomidae*)
- **Size:** up to 5 cm
- **Depth:** 1-40 m
- **Diet:** Carnivore
- **Activity:** Nocturnal
- **Rarity:** Common
- **Habitat:** Sand and silty bottom, buried by day
- **Reproduction:** Broadcast spawner, Gonochoric
- **Hazard:** Dangerous, Venomous

## How to recognise it

- flattened segmented worm with a pattern of dark spots down the back
- dense tufts of fine white bristles along both sides
- red feathery gills between the bristle tufts
- length up to 5 cm

A flat segmented worm patterned in dark spots, fringed on both sides with tufts of fine white bristles and red feathery gills between them. Five centimeters (2 in), buried in sand by day and out over the bottom at night.

The bristles are the entire reason to know it. They are hollow, brittle, filled with a toxin, and designed to detach: touch one and dozens break off in the skin, too fine to pull out, releasing venom as they dissolve. The burn is immediate and lasts for hours, and the itching can go on for days. Adhesive tape lifts some of the fragments; vinegar helps; scratching makes everything worse.

It is a scavenger and a predator, taking carrion, small invertebrates and anything soft it can find on the bottom, and it turns up quickly around anything dead.

Almost every injury involves a hand placed on sand at night, or a worm picked up out of curiosity because it looks like a fluffy caterpillar. It is not a caterpillar.

## Also known as

- **Russian:** Золотой огненный червь

## Range

Red Sea

---

*Source: [Red Sea Creatures](https://redseacreatures.com/taxon/invertebrate/worms/fireworms/red-gilled-mudworm)*
*Updated: August 15, 2026*