White Furrow-shell

Abra alba can grow to up to 2.5 cm (1 in) long but a more usual size is 1.5 centimetres. It has a pair of thin brittle valves that are translucent, semi-shiny and a dirty white colour with a pale brown periostracum. The shape is roughly oval and the posterior and anterior dorsal margins are almost straight and slope to rounded ends. Both margins are smooth and the anterior margin is a little longer than the posterior one. The valves have a sculpture of fine concentric lines and the growth stages of the animal are visible. The interior of the valves is somewhat glossy and the adductor muscle scars may be visible. The small brown ligament that holds the valves together is exterior.

Abra alba is found on the coasts of northwest Europe and the Mediterranean Sea at depths down to 200 m (656 ft). It is common around the British Isles and in the North Sea. It prefers fine, silty sand, but is also found in mud or gravel.