Truncate Donax

• GeneralIt is gathered by hand with a rake in the surf itself.
• It moves with the tides: it lets the wave carry it, reburies itself, and in that way follows the water level through the day.
• Its shell varies so much in colour and pattern that two individuals from the same beach can look like different species.
• It follows the tide. Coquinas let the wave carry them, rebury themselves within seconds and so move up and down the beach with the tide, a technique known as swash-riding.
• That calls for extremely fast digging: it is among the quickest burrowing bivalves, and individuals between 0.5 and 2.5 cm are the fastest of all.
• It senses wave vibrations to know when to emerge. Related species respond to pressure signals of barely 20 pascals.
• In Spain it is the basis of the coquinas of Huelva and of the stew of the Cádiz coast.
• As a filter feeder of the surf zone it accumulates viruses and toxins, and it has been implicated in outbreaks of hepatitis A.

Skeleton type

Invertebrate - external calcareous bivalve shell (mollusc)

Habitat and environment

Shore sand in the surf zone

Sexual maturity

1 year

Sources consulted: Wikipedia (es): Donax trunculus · ScienceDirect (Hughes 1989) · Science Advances, How colonial animals evolve · Wikipedia, Zooid