---
title: Rainbow Wormfish (Gunnellichthys irideus)
scientific_name: Gunnellichthys irideus
common_name: Rainbow Wormfish
taxon: Dartfishes
published: 2026-08-08T14:32:23.438Z
updated: 2026-08-08T15:22:03.360Z
tags: Rainbow Wormfish, Gunnellichthys irideus, Dartfishes, Red Sea, Marine Life, Diving
url: https://redseacreatures.com/taxon/fishes/bony-fishes/dartfishes/rainbow-wormfish
---

# Rainbow Wormfish (*Gunnellichthys irideus*)

## Quick facts

- **Group:** Dartfishes (*Ptereleotrinae*)
- **Size:** up to 12 cm
- **Depth:** 5-35 m
- **Diet:** Planktivore
- **Activity:** Diurnal
- **Rarity:** Rare
- **Habitat:** Open sand and fine rubble away from reef
- **Reproduction:** Egg layer, Gonochoric

## How to recognise it

- extremely elongate, worm-like body
- pale with a bright orange or red stripe along the flank
- swims in a snake-like wriggle just above the sand
- length up to 12 cm

A fish built like a piece of string: extremely elongate, pale, with a bright orange or red stripe running the length of the flank, and a swimming action that is closer to a wriggle than to normal fin propulsion. It works just above open sand, away from the reef, at about 12 cm (5 in) long.

The shape is not decorative. Wormfishes live in burrows and need to enter them tail-first or head-first at speed, and the body is the diameter of the hole. Disturbed, one vanishes into the sand so quickly that divers often doubt they saw anything. Feeding is done in the open on small drifting animals, usually singly or in loose pairs, and always with an escape route directly below. It is uncommon here and easy to miss - a thin bright line moving over sand reads as reflection or debris until it turns.

## Also known as

- **English:** Plain Wormfish
- **Portuguese:** Peixe-lombriga-iridescente
- **Russian:** Радужный червевидный бычок

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*Source: [Red Sea Creatures](https://redseacreatures.com/taxon/fishes/bony-fishes/dartfishes/rainbow-wormfish)*
*Updated: August 8, 2026*