Depth
Pecten · Molluscs (Octopus, Nudibranchs & Shellfish)

Pilgrim's Scallop

Pecten jacobaeus

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 Mollusca
Genus Pecten
Species jacobaeus

Mollusc

Identification & Biology

  • IdentificationA large, fan-shaped scallop with one flat and one convex shell valve. The flat (upper) valve is reddish-brown, and the convex (lower) valve is pale cream to white. Prominent radiating ribs and a straight hinge line with two ear-like wings.
  • SizeShell diameter up to 15 cm. A large and distinctive bivalve.
  • Social HabitCan be solitary or in scattered groups on the seabed. Capable of swimming by rapidly clapping its shells together, jetting water to escape predators such as starfish.
  • HabitatSandy and gravelly bottoms, often in open areas on the continental shelf.
  • Depth10 to 250 m. Most common between 25 and 100 m.
  • Feeds OnPlankton and suspended organic particles filtered from the water.
  • DistributionEastern Atlantic and throughout the Mediterranean Sea. Present in Maltese waters.
  • DescriptionPecten jacobaeus is the Mediterranean scallop, closely related to the Atlantic great scallop. Its fan-shaped shell has been a symbol of pilgrimage since the Middle Ages, carried by pilgrims returning from the shrine of Santiago de Compostela in Spain. Like all scallops, it has a row of simple eyes along the mantle edge that can detect movement and changes in light, allowing it to clap shut or swim away from approaching predators.

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.

Pilgrim's Scallop species card

Biology

Behaviour & Diet

Feeding Strategy

A filter feeder that draws water across its gills using ciliary action, capturing phytoplankton, bacteria and fine organic detritus from the water column.

Filter feeder

Reproduction

A functional hermaphrodite that releases both eggs and sperm into the water column, typically spawning in spring. Larvae are planktonic before settling on hard substrate.

Hermaphrodite

Behaviour & Defence

Detects approaching predators like starfish using numerous blue eyes along its mantle edge, then escapes by clapping its valves to jet away in an erratic swimming motion.

Jet swimming

Dive with diveshack

Where to Encounter in Malta

The following dive sites offer strong habitat match for Pecten jacobaeus. 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