This is the Banded Venus (Clausinella fasciata), a small marine clam in the Venus clam family, Veneridae. It is known for its attractive, often brightly patterned shell and is usually found buried in coarse sand or gravel on the seabed.

Location:
The Banded Venus is found across north-west European coasts, including the British Isles, from northern Norway south along the Atlantic to the Iberian Peninsula, and throughout the Mediterranean Sea. It lives in shallow sublittoral zones, which are areas just below the low tide line, in both sheltered bays and more open coastal waters.

Average Size:
Adults typically measure 15–25 millimetres in length, though rare individuals may reach up to 28–30 millimetres.

Family:
Veneridae (Venus Clams)

Species:
Clausinella fasciata

Shell Description:
The shell is small, solid, and ranges from triangular to oval in shape. Its surface has fine concentric growth lines, sometimes with additional radial markings. The colour varies, usually pale cream or white, with distinctive bands or streaks of reddish-brown, pink, purple, or yellow. Older shells may develop broader concentric ridges. The inside of the shell is smooth and generally dull white.

Habitat:
The Banded Venus lives just under the surface of coarse sand, gravel, or mixed sediments, often containing shell fragments. It is most commonly found in the sublittoral zone, from just below low water down to about 100 metres. It is rarely found on true intertidal flats and prefers stable, coarse substrates rather than fine mud or shifting sand.

Feeding:
The Banded Venus feeds by filtering water for food. It has two tube-like extensions called siphons that reach through the sand while the clam stays buried. The inhalant siphon draws water into the clam, carrying tiny food particles such as plankton and organic matter. The exhalant siphon then pushes the filtered water back out into the seabed. This system allows the clam to feed efficiently while remaining protected under the sand.

Movement and Behaviour:
While it usually remains buried and relatively stationary, the Banded Venus can use its muscular foot to dig or shift position if disturbed or if local conditions change.

Reproduction:
Males and females release eggs and sperm into the surrounding water, where fertilisation occurs externally. The resulting larvae float in the water column for a period of time before settling on the seabed and developing into juvenile clams.

Ecological Role:
By filtering suspended particles from the water, the Banded Venus helps maintain water clarity and contributes to nutrient cycling in seabed habitats. It is a food source for fish, crabs, and other predators, and its empty shells provide microhabitats for small marine organisms.

Conservation Status:
The Banded Venus is common in suitable habitats and is not currently considered threatened. Local populations may be affected by pollution, seabed disturbance, and wider changes in coastal environments.