Knowra Mollusca Mollusca Mollusca is a phylum of invertebrate animals that includes snails, clams, chitons, squids, and octopuses. Most mollusks have a muscular foot, a visceral mass, and a mantle, though these structures vary widely across the phylum.
Mantle (mollusk) : A fold of tissue in mollusks that covers the visceral mass and often secretes a shell. Its shell-secreting role links the familiar shell to the animal’s underlying anatomy.
Gastropoda : The largest mollusk class, including snails, slugs, limpets, and nudibranchs. Gastropods display the familiar crawling foot and great diversity of shell forms.
Mollusk shell formation : The process by which mantle tissues deposit mineral and organic layers to build a mollusk shell. It explains how a living tissue produces and repairs the phylum’s characteristic hard structures.
Kimberella : A fossil organism from the Ediacaran Period, sometimes interpreted as an early mollusk or close relative. Its fossils are among the oldest candidates for a mollusk-like animal.
Aquaculture : The farming of aquatic organisms, including fish, crustaceans, algae, and mollusks. Oysters, mussels, and other mollusks are widely raised through aquatic farming.
Radula : A ribbon-like feeding organ bearing rows of tiny teeth, found in most mollusks but absent from bivalves. Its presence in many mollusks and absence in bivalves illustrates variation in feeding anatomy.
Bivalvia : A mollusk class including clams, mussels, oysters, and scallops, with two hinged shell valves. Bivalves show a distinct body plan adapted to filter feeding and burrowing.
Bivalve filter feeding : A feeding method in which bivalves draw water through their gills and capture suspended particles. This specialized feeding strategy helps explain bivalves’ gills and ecological role.
Aculifera : A proposed mollusk grouping that unites chitons with worm-like mollusks bearing spicules. Its proposed relationships offer one account of early mollusk diversification.
Pearl : A layered biomineral structure formed by some mollusks around an irritant or implanted nucleus. Pearls are a valuable material produced by the shell-forming tissues of certain mollusks.
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