Let’s get some knowledge about how do the bivalves move around? A large group of molluscs have shells made up of two halves or valves; hence they are called the bivalves. A common feature of the bivalves is their large fleshy foot and this is used to move around in a way different from that of the chitins.
How do the bivalves move around?
The bivalves tend to be burrowers and they spoke out the foot into the sandy or muddy bottom, the end swells to anchor the foot, and then the rest of the animal is drawn up and the foot extended again.
This is obviously a very slow process and not surprisingly the bivalves do not feed in the same way as the more mobile chitins. The mantle forms two siphons. Water is drawn through one into a large mantle cavity where it passes over the equally large gills before leaving by the other siphon.
The gills not only extract oxygen from the water, they are modified to filter our suspended food particles which are then passed to his mouth and eaten. The devolves have no head and no rasping radula.
How do Mussels fix themselves to surfaces high above the ground?
You many have wandered under a pier at low tide and glanced up to see masses and masses of mussels hanging high above you on the supports. In contrast to the chiton which ‘sticks’ itself to the rock surface, the mausels are actually hanging from surfaces of the pier on fine, strong threads. These are called byssus threads and are secreted by the foot.
Mussels differ from burrowing bivalves in that they prefer to secure themselves in one place, ‘hanging around’ on rocks, piles and posts until the tide covers them again. Young mussels do move around a little by using the foot, but once they get older they settle down in one spot.
Many to the bivalves are of importance to us because we eat them in large quantities. Cockles, mussels, oysters and scallops are all popular as seafood.
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