Sabella Spallanzanii | diveshack Marine Life Guide

Polychaete

Identification & Biology

IdentificationA large tube-dwelling worm with a spectacular fan-shaped crown of feathery tentacles (radioles) that spirals out of a tough, flexible, parchment-like tube. The fan can be brown, orange, white, banded, or striped. The tube is greyish and often encrusted.
SizeFan diameter up to 15 cm. Tube length up to 40 cm. One of the largest fan worms in the Mediterranean.
Social HabitSolitary. Lives permanently in its tube, extending the fan to filter feed. Retracts instantly when it detects a shadow or vibration. Very sensitive to movement.
HabitatSandy and muddy bottoms, harbour walls, pier pilings, and sheltered rocky areas. The tube projects upward from the substrate.
Depth0 to 30 m. Common in sheltered shallow waters.
Feeds OnPlankton and suspended organic particles captured by mucus on the feathery radioles and transported to the mouth by ciliary action.
DistributionMediterranean Sea and eastern Atlantic. Also introduced to Australia, New Zealand, and other regions. Common in Maltese waters.
DescriptionSabella spallanzanii is one of the most elegant animals on Mediterranean reefs. Its spiralling fan of feathery tentacles creates a beautiful display as it filters the water for food. The fan retracts into the tube with lightning speed at the slightest disturbance, making it notoriously difficult to photograph. Patience and slow, careful movement are essential to observe the fully extended fan.

Range

Habitat & Distribution

Found across the Mediterranean, inhabiting reef & open environments. Active from the surface down to 40m depth.

Where Malta divers have spotted this species

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Sightings are logged by divers using our What Did You See? dive-log tool. View the full live sightings map.

Detail

Preferred Environment

Reef & Open habitats, typically at depths of 0-40m. Most commonly encountered by divers at the shallower end of its range.

Encounter Tips

Best approached slowly and calmly. Avoid casting shadows directly over the animal. Neutral buoyancy and patience increase encounter success significantly.

Biology

Behaviour & Diet

Feeding Strategy

Extends a large, spiralling crown of feathery radioles from its tube to trap suspended particles, phytoplankton and bacteria in mucus. Cilia along the radioles sort particles by size, directing food to the mouth and rejecting sediment.

Filter feeder

Reproduction

Sexes are separate, with both males and females releasing gametes into the water column during spring and summer. Fertilised eggs develop into trochophore larvae that spend several weeks in the plankton before settling.

Broadcast spawner

Behaviour & Defence

Withdraws its entire radiole crown into its flexible, parchment-like tube within milliseconds when it detects shadows, vibrations or water pressure changes. The tube itself provides a tough physical barrier against small predators.

Rapid retraction

Dive with diveshack

Where to Encounter in Malta

The following dive sites offer strong habitat match for Sabella spallanzanii. All are accessible on a guided dive with diveshack.

5-30m

North Malta

Cirkewwa

Rocky reef with caves, arches and ledges hosting a rich diversity of reef species.

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5-50m

Gozo

Blue Hole

One of the Med's most famous reef dive sites. Rocky walls and archways covered in life.

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18-36m

South Malta

Um El Faroud

The wreck lies on a sandy bottom surrounded by rocky reef -- a diverse habitat attracting reef species.

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IUCN Red List Least Concern

Conservation Status

This species is assessed as Least Concern on the IUCN Red List. Mediterranean populations face ongoing pressure from fishing activity, habitat degradation, and climate-driven changes to prey availability.

Source: iNaturalist Guide #888
by Lesley Clements (CC BY-SA)
diveshack Mediterranean Marine Life guide