Bearded Fireworm in Cozumel
Bearded Fireworm (*Hermodice carunculata*) in Cozumel: how to identify it, why its bristles burn, and what to do if you touch one.
A flattened segmented worm in green-brown and red, fringed along both sides with tufts of white bristles that look soft and are not.
Quick ID
| Scientific name | Hermodice carunculata |
|---|---|
| Group | Worms & Drifters |
| Typical size | 10–25 cm |
| Depth range | 2–25 m |
| When to see it | Year-round |
| Active | Mostly night |
| Conservation status | Least Concern |
| Notes | Venomous — do not touch · Best seen on night dives |
Where You Will See It In Cozumel
Rubble, coral bases and dead coral at Tormentos, Yucab and Paradise Reef, most active at night.
Reliable sites: Tormentos, Yucab, Paradise Reef.
Behaviour
Feeds on coral tissue, anemones and dead animals. When threatened it flares the white bristles outward — that flare is the warning.
Commonly Confused With
- Nudibranchs — Nudibranchs have exposed gills but no rows of white bristles along the flanks.
- Flatworms — Flatworms glide smoothly with no bristles or visible segments.
Diving Etiquette And Safety
The white bristles are hollow, venom-bearing and detach into skin on the lightest contact, causing burning pain that can last for days. Never handle one, and be careful where gloves and knees go on a night dive.
Part of the Cozumel marine life guide · see Cozumel dive sites · plan your Cozumel dive trip
Photo: Diego Delso, CC BY-SA 4.0, via Wikimedia Commons.
