Istrian seabed

Did you know that a clam can weigh up to 200 kg and reach a length of one metre!? Of course, we're talking about the Giant Clam - the largest bivalve in the world - which is but one of some 20 thousand bivalve species living in seas around the world.

The Adriatic Sea is rich in fish and other marine life, and it is home to many different types of bivalves, as well as to 200 protected species widely known for their beauty. Seven protected species inhabit the seafloor along the coast of the Istrian peninsula. These are:

- the noble pen shell
- the brittle pen shell
- the European date mussel
- the zoned miter
- the common piddock
- the cowrie shell
- the helmet tun or giant tun

These species deserve to be protected and preserved not only because of their beauty but also because they contribute to the rich diversity of the Adriatic seabed.

Bivalves are molluscs; they are called bivalves because their calcareous shells consist of two parts called valves. They are one of the oldest species of animals, a fact confirmed by a fossil record consisting of some 15,000 fossil species.  Bivalves are sedentary for most of their lives, never leaving their home or the seafloor. New bivalves grow from larvae that use fish as hosts, attaching themselves to the fish’s fins or gills; when grown, they break free from the host and drop to the bottom of the sea. Like most animals they have eyes, a mouth, a stomach and even a foot that holds them to the seafloor while they search for a home and food. Bivalves often bury themselves in the soft seabed, while some, like the European date mussel, bore holes in soft rocks.

The Nature Protection Act regulates the protection of strictly protected species, which include bivalves. It is prohibited to remove them from nature, intentionally capture or kill them, intentionally damage or destroy their development stages, or destroy their reproducing grounds. The Nature Protection Act also prohibits the keeping, transport, sale, and trading or offering for sale or trade of strictly protected species, either living or dead.

Zaštićeni školjkaši istarskog podmorja
I molluschi protetti del fondale marino istriano
[pdf]
Protected bivalves of the Istrian seabed
Geschützte Schalenweichtiere der istrischen Unterwasserwelt
[pdf]