Twin Fanworm

Overview

The Twin Fanworm is a distinctive sedentary tube worm known for its striking, double-spiral crown of feathery tentacles. Often found in groups, this species is highly sensitive to light and movement, rapidly retracting into its protective tube when disturbed.

Distribution & habitat

This species is found throughout the eastern Atlantic Ocean, ranging from the British Isles down to the Mediterranean Sea. It typically inhabits shaded rocky overhangs, crevices, and occasionally deep rock pools in the sublittoral zone, often preferring areas with some sediment.

Appearance

The most recognizable feature of the Twin Fanworm is its branchial crown, which consists of up to 200 tentacles arranged in interlocking spirals or whorls. These plumes vary in color from white to tan or reddish-brown, often featuring banded patterns. The worm lives within a soft, parchment-like tube constructed from mucus, mud, and silt. A key identification feature is the tube's opening, which appears pinched into a figure-eight shape when the worm is retracted.

Feeding

As a suspension feeder, the Twin Fanworm extends its feathery radioles into the water column to capture plankton and suspended organic particles. It is most efficient at feeding in gentle currents, which help deliver food to the crown.

Reproduction

This species reproduces sexually, releasing gametes directly into the water column where fertilization occurs.