The queen scallop is a medium-sized scallop, a marine bivalve (with a hinged double shell). The shell is variable in colour, but often light-pink to brown or orange with between 19-22 radiating ribs or ridges on both valves. This species is primarily found on firm, sandy gravel or mud at depths of 100 meters or more.

Behaviour

The queen scallop uses jet propulsion to move. By using valves to open and close their shells, they suck in and expel water to “swim”.

It is a filter feeder consuming both phytoplankton and zooplankton. The filtering apparatus is equipped with small hair-like cilia that move the trapped plankton to the mouth.

Queen scallops are hermaphroditic. The gonad (roe) contains in excess of 100 million eggs with the pink/orange part being female and the white part male. Both eggs and sperm are released directly into the open sea where cross-fertilization takes place – a process called “spawning”. The larvae drift in the water column for four to seven weeks before drifting to the sea floor where they attach themselves to a substrate.

Size

• Diameter of single valve: up to 9cm
• Average lifespan: up to 5 years

Status

Common

Distribution

Queen scallops are found around the entire coast of the British Isles, but are less abundant off the far north-east coast of Scotland.

When to see

January to December

Facts

• Scallops have 50-100 light detectors embedded at the base of the sensory tentacles that run along the outer edges of their upper and lower shells. These allow them to respond to light and movement, protecting them from predators.
• The scallop is the only bi-valve mollusc (having a hinged, double shell) that can move freely across the ocean.