Adult dating mollusk virginia
In some species the valves are reduced or covered by the girdle tissue.The most anterior plate is crescent-shaped, and is known as the cephalic plate (sometimes called a "head plate", despite the absence of a complete head).These plates overlap slightly at the front and back edges, and yet articulate well with one another.Because of this, the shell provides protection at the same time as permitting the chiton to flex upward when needed for locomotion over uneven surfaces, and even allows the animal to curl up into a ball when dislodged from rocks.The oesophagus, in turn, opens into a stomach, where enzymes from a digestive gland complete the breakdown of the food.
They live on hard surfaces, such as on or under rocks, or in rock crevices.
The radula is used to scrape microscopic algae off the substratum.
The mouth cavity itself is lined with chitin and is associated with a pair of salivary glands.
Some species live quite high in the intertidal zone and are exposed to the air and light for long periods.
Most species inhabit intertidal or subtidal zones, and do not extend beyond the photic zone, but a few species live in deep water, as deep as 6,000 m (20,000 ft). This is in contrast to the bivalves, which were able to adapt to brackish water and fresh water, and the gastropods which were able to make successful transitions to freshwater and terrestrial environments.
The mouth is located on the underside of the animal, and contains a tongue-like structure called a radula, which has numerous rows of 17 teeth each.