Alcyonium · Cnidarians (Jellyfish, Anemones & Corals)

Mediterranean Sea Finger

Alcyonium acaule

0-40m

Depth Range

Variable

Max Size

Mediterranean

Distribution

Cnidarian

Identification & Biology

IdentificationA soft coral that forms upright, finger-like or club-shaped lobes growing from a common base. Orange to red when alive, with tiny white polyps that extend to feed. The texture is fleshy and rubbery.
SizeColony height up to 25 cm. Individual lobes are 3 to 6 cm in diameter.
Social HabitColonial. Found in groups on shaded walls and overhangs. Polyps extend at night and in strong currents, retracting when disturbed.
HabitatShaded rocky walls, cave entrances, and overhangs with good water flow.
Depth10 to 80 m. Most common between 15 and 50 m.
Feeds OnPlankton and suspended organic particles captured by the extended polyps.
DistributionMediterranean Sea. An endemic Mediterranean species. Present in Maltese waters.
DescriptionAlcyonium acaule is the only widely encountered soft coral in the Mediterranean. Its orange, finger-like lobes are a distinctive feature of deeper rocky walls and cave entrances across Malta. When the tiny white polyps are extended, the surface looks furry; when retracted, it appears smooth and rubbery. Unlike tropical soft corals, it is slow-growing and restricted to the Mediterranean basin.

Range

Habitat & Distribution

Found across the Mediterranean, inhabiting rocky reef 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

Rocky Reef 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

A colonial soft coral whose polyps extend at night to capture zooplankton and fine organic particles from the water column. Each polyp bears eight pinnate tentacles for efficient particle trapping.

Nocturnal feeder

Reproduction

Reproduces sexually by releasing eggs and sperm in summer. Larvae settle on hard substrate. Also propagates asexually through colony fragmentation.

Seasonal spawning

Behaviour & Defence

Polyps retract into the fleshy colony mass when disturbed, leaving a smooth, rubbery surface. Calcareous spicules embedded in the tissue provide structural support and deter grazers.

Retraction

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Where to Encounter in Malta

The following dive sites offer strong habitat match for Alcyonium acaule. 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