This sturdy, oval-shaped shell is half of a Spiny Cockle (Acanthocardia aculeata). It typically measures between 50 and 115 mm in length. The shell has 20–22 raised ribs radiating from the centre to the edges, each with sharp spines along the middle. Concentric rings can also be seen between the ribs. It has a heart-shaped profile with a crenulated (scalloped) margin, and the inside is smooth, white, with grooves corresponding to the ribbing.

Location:
Found in the Mediterranean Sea and the Northeast Atlantic—from Scandinavia to northwest Africa. Lives in sandy to muddy seabeds at depths usually between 5 and 100 metres.

Average Size:
50–115 mm, commonly around 75 mm.

Family:
Cardiidae (Cockles)

Species:
Acanthocardia aculeata

Ecological Role:
A filter feeder, the Spiny Cockle draws in phytoplankton and suspended particles using its siphons. Burrowing in sediment, it stabilises the seabed and contributes to nutrient cycling.

Conservation Status:
Not currently considered threatened. It is relatively common in its habitat and even harvested locally for food in some areas.

Collection Date:
Collected in Torbay in 1900.