Mollusks may be found in the water, such as clams, octopus, and oysters; however, there are also mollusks that live on land, such as snails and slugs. These mollusks come in a wide variety of shapes and sizes. There are between 50,000 and 200,000 different species of mollusks alive today, making them the second biggest group of invertebrates on the planet.
Mollusks may be broken down into a few different subgroups, the most common of which are univalve, bivalve, and cephalopod mollusks. The octopus, the cuttlefish, and the squid are all examples of the class of animals known as cephalopods. The term “univalves” refers to mollusks that only have one shell, like snails, whereas “bivalves” refers to mollusks that have two shells that are connected to each other. Almost all univalves have a protective shell that forms in a spiral pattern. This is true for almost all univalves. The one and only exception to this rule is snails, who, despite the fact that they have lost the capacity to produce a shell as a result of evolution, are nonetheless classified as univalve organisms.
Mollusks like scallops and clams are both examples of bivalve mollusks. Even though they are classified as univalves, snails are really members of the class of animals known as gastropods. This classification also includes slugs, both marine and terrestrial, limpets, sea cucumbers, and sea hares. Mollusks, whether univalve or bivalve, are often admired for the beauty and complexity of their shells. Mollusks are responsible for the creation of almost all of the shells that can be found on beaches all over the globe. The conch, the cowrie, and the whelk are all examples of univalve gastropods, and their shells are considered to be among the most valuable of all mollusk shells.