Bivalves are molluscs with a body compressed between two usually similar shell valves joined by an elastic ligament.

The shell of Fabulina fabula is brittle and flattened and grows to a length of twenty millimeters.

In a study off the Belgian coast in 2006, this species was found at a maximum density of over a thousand individuals per square metre.

[4] Fabulina fabula burrows in clean or slightly muddy sand and has a large foot and two long siphons which it extends to the surface of the sediment.

[6] Individual molluscs are either male or female and gametes are liberated into the water table during spring and summer.