Importance of Mollusks
Mollusks are important in a variety of ways, including as food, for decoration, in jewelry, and
in scientific studies. They are even used as roadbed material and in calcium supplements.
Edible species of mollusks include numerous species of clams, mussels, oysters, scallops,
marine and land snails, squid, and octopus. Many species of mollusks, such as oysters, are
farmed in order to provide additional food sources (Figure12.9).
Figure 12.9: An oyster harvest in France. ( 14 )Two natural products of mollusks used for decorations and jewelry arepearlsandnacre,
or mother of pearl. A pearl is the hard, round object produced within the mantle of a
living shelled mollusk. Fine quality natural pearls have been highly valued as gemstones and
objects of beauty for many centuries. The most desirable pearls are produced by oysters and
river mussels.
Nacre is an iridescent inner shell layer produced by some bivalves, some gastropods, and
some cephalopods, and has been used in sheets on floors, walls, counter tops, doors, and
ceilings. It is also inserted into furniture; it can be found in buttons, watch faces, knives,
guns, and jewelry; and is used as decorations on various musical instruments.
Several mollusks are ideal subjects for scientific investigation, especially in the area of neuro-
biology. The giant squid has a sophisticated nervous system and a complex brain for study.
The California sea slug, also called the California sea hare, is used in studies of learning and
memory, since it has a simple nervous system, consisting of just a few thousand large, easily
identified neurons, but also a variety of learning tasks.