The three main types of mollusks are gastropods, bivalves, and cephalopods. They have three pairs of ganglia and two nerve c ords. The Animal Kingdom contains these seven Phyla: Porifera, Cnidaria, Platyhelminthes, Annelida, Mollusca, Arthropoda, and Chordata. Bivalves include clams, oysters, mollusks, clams, and many other affiliated shell families. The current 7 extant classes include the following. The remaining classes (Polyplacophora, Aplacophora, and Monoplacophora) have fewer species. Bivalves: A class of marine and freshwater mollusks with compressed bodies within a shell. The bivalves have sensory cells enabling them to distinguish touch, chemical changes, and light. The study of mollusks is called malacology (mal-uh-col-oh-gee) which means “the study of animals with soft bodies.” The seven living classes of mollusks are Aplacophora, Bivalva, Cephalopoda, Gastropoda, Monoplacophora, Polyplacophora and Scaphopoda. The Phylum Mollusca is estimated to include 100,000 species. Gastropods make up the largest class of mollusks, and they include both snails and slugs. The smallest mollusks are snails that are microscopic in size. Gastropods include snails. 1 / Gastropods are single shells coiled around a center axis. Although the phylum Mollusca are made up of a set of incredibly diverse animals, there are certain characteristics which aid to classify them. Gastropods include snails. Phylum: Mollusca Mollusca itself has 9 classifications, with 7 extant representativies and 2 extinct classes. Mollusks are subdivided into seven classes with most species found in three of those classes: Gastropoda, Bivalvia, and Cephalopoda. Phylum: Mollusca Mollusca itself has 9 classifications, with 7 extant representativies and 2 extinct classes. The current 7 extant classes include the following. Types of Mollusks. Mollusks refer to are a large group of soft-bodied invertebrate animals. The bodies of animals are made up of differentiated tissues to perform an equally specialized task, sometimes in to or three levels of differentiation (excluding sponges). Types of Mollusks. Mollusks are classified by number of shells or foot shape. GASTROPODS This class has more than 60 000 unknown species, making it the largest. Whether you are looking to discover mollusks characteristics, classification of mollusca and/or information about all types of mollusks, this article is for you. The smallest mollusks are snails that are microscopic in size. The thorn shell, Acanthina angelica The phylum Mollusca is the second most diverse phylum after Arthropoda with over 110,000 described species. They are typically divided into ten classes, of which two are extinct. GASTROPODS This class has more than 60 000 unknown species, making it the largest. There are approximately 160,000 living species and probably 70,000 extinct species of mollusks. Gastropods, like slugs and snails, can live on land or in the water. torsion). Monoplacophora Fig. BIVALVES Mollusks are classified by number of shells or foot shape. There are approximately 160,000 living species and probably 70,000 extinct species of mollusks. The major classes of living mollusks include gastropods, bivalves, and cephalopods (Figure below). Mollusks may be primitively segmented, but all but the monoplacophorans characteristically lack segmentation and have bodies that are to some degree spirally twisted (e.g. They are typically divided into ten classes, of which two are extinct. A large group of soft-bodied invertebrate animals shell, Acanthina angelica the phylum Mollusca is estimated to 100,000. 160,000 living species and probably 70,000 extinct species of mollusks phylum: Mollusca Mollusca itself 9... 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