Depth
Cerianthus · Cnidarians (Jellyfish, Anemones & Corals)

Cylinder Anemone

Cerianthus membranaceus

0-40m
Depth Range
Variable
Max Size
Mediterranean
Distribution
0-40m
Depth Range
Variable
Max Size
Reef & Open
Habitat
Carnivore
Diet
Solitary
Social
LC
IUCN Status
Kingdom Animalia
Phylum Cnidaria
Genus Cerianthus
Species membranaceus

Cnidarian

Identification & Biology

  • IdentificationA large, tube-dwelling anemone with an extremely long, smooth, translucent column and two distinct rings of tentacles. The outer tentacles are long and numerous, while the inner (labial) tentacles are shorter. Colour ranges from brown and purple to pale cream.
  • SizeColumn length up to 40 cm (most is buried). Tentacle span up to 30 cm across.
  • Social HabitSolitary. Lives in a tough, felt-like tube buried in soft sediment. Cannot retract fully into the tube. The tentacles wave gracefully in the current.
  • HabitatSandy and muddy bottoms. Requires soft substrate deep enough to accommodate its long tube.
  • Depth5 to 40 m. Common on sandy substrates adjacent to rocky reefs.
  • Feeds OnPlankton, small fish, and organic particles captured by the tentacles.
  • DistributionEastern Atlantic and throughout the Mediterranean Sea. Common in Maltese waters on suitable sandy substrates.
  • DescriptionCerianthus membranaceus is one of the most elegant animals on Mediterranean sandy seabeds. Its crown of long, waving tentacles is unmistakable and comes in a beautiful range of colours, from rich chocolate brown to cream, violet, and bicoloured forms. Despite its appearance, it is not a true anemone but belongs to a separate order (Ceriantharia). The tube it lives in can extend 50 cm or more into the sediment.

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.

Cylinder Anemone species card

Biology

Behaviour & Diet

Feeding Strategy

Extends a wide crown of long tentacles at night to trap passing plankton and small invertebrates. During the day it often retracts partially into its buried tube.

Nocturnal predator

Reproduction

Reproduces sexually by releasing gametes into the water column. Fertilised eggs develop into planula larvae that drift before settling on soft substrate to form new tubes.

Broadcast spawner

Behaviour & Defence

Withdraws rapidly into its tough parchment-like tube when disturbed, pulling the entire tentacle crown below the sediment surface. The tube itself can extend over 40 cm into the substrate.

Rapid retraction

Dive with diveshack

Where to Encounter in Malta

The following dive sites offer strong habitat match for Cerianthus membranaceus. 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.

View dive site ›
5-50m
Gozo

Blue Hole

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

View dive site ›
18-36m
South Malta

Um El Faroud

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

View dive site ›
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