1. Gastropoda: This is the largest class of mollusks, encompassing snails, slugs, sea slugs (nudibranchs), and limpets.
* Characteristics: They have a single, spiraled shell (except slugs) and a muscular foot that they use for locomotion.
* Examples: Garden snails, sea snails, abalone, nudibranchs.
2. Bivalvia: This class includes clams, oysters, mussels, and scallops.
* Characteristics: They have two hinged shells that enclose their soft bodies. They are filter feeders, using gills to extract food from the water.
* Examples: Oysters, clams, mussels, scallops.
3. Cephalopoda: This class contains squid, octopus, cuttlefish, and nautilus.
* Characteristics: Highly intelligent, they have a well-developed nervous system and are known for their ability to change color and texture. They also have a beak-like mouth and tentacles.
* Examples: Squid, octopus, cuttlefish, nautilus.
4. Polyplacophora: This class includes chitons.
* Characteristics: They have an oval body covered by eight overlapping plates, giving them a segmented appearance.
* Examples: Chitons
5. Scaphopoda: This class consists of tusk shells.
* Characteristics: They have a long, slender, tube-shaped shell that is open at both ends.
* Examples: Tusk shells
6. Monoplacophora: This class includes a small group of primitive marine mollusks.
* Characteristics: They have a single, cap-like shell and a segmented body.
* Examples: Neopilina galatheae
It's important to remember that this is just a brief overview. The phylum Mollusca is incredibly diverse, with thousands of different species exhibiting unique adaptations and lifestyles.