The mantle is an organ found in mollusks. It is the dorsal body wall covering the main body, or visceral mass. The epidermis of this organ secretes calcium carbonate to create a shell. Classes Caudofoveata Aplacophora Polyplacophora Monoplacophora Bivalvia Scaphopoda Gastropoda Cephalopoda † Rostroconchia The mollusks or molluscs are the large and diverse phylum Mollusca, which includes a variety of familiar creatures well-known for their decorative shells or as seafood. ... It has been suggested that this article or section be merged with skin. ... Calcium carbonate is a chemical compound, with chemical formula CaCO3. ...

== Shell formation == john

Nacre is secreted by the ectodermic cells of the mantle tissue of most mollusks. Mollusk blood is rich in a liquid form of calcium. In these mollusks the calcium is concentrated out from the blood where it can crystallize as calcium carbonate (CaCO₃). The individual crystals of each layer differ in shape and orientation. Nacre is continually deposited onto the inner surface of the animal's shell (the iridescent nacreous layer, also known as mother of pearl), both as a means to smoothen the shell itself and as a defense against parasitic organisms and damaging detritus. Nacre, also known as mother of pearl, is a naturally-occurring organic-inorganic composite. ... Organs derived from each germ layer. ... Drawing of the structure of cork as it appeared under the microscope to Robert Hooke from Micrographia which is the origin of the word cell. Cells in culture, stained for keratin (red) and DNA (green). ... Human blood smear: a - erythrocytes; b - neutrophil; c - eosinophil; d - lymphocyte. ... General Name, Symbol, Number calcium, Ca, 20 Chemical series alkaline earth metals Group, Period, Block 2, 4, s Appearance silvery white Atomic mass 40. ... Various seashells Danielle A shell is the hard, rigid outer covering, or integument, allanimals. ... The iridescence of the Blue Morpho butterfly wings. ... Nacre, also known as mother of pearl, is a naturally-occurring organic-inorganic composite. ... A parasite is an organism that spends a significant portion of its life in or on the living tissue of a host organism and which causes harm to the host without immediately killing it. ...

The calcium carbonate layers are generally of two types: an outer, chalk-like prismatic layer and an inner pearly, lamellar or nacreous layer. The layers may incorporate a substance called conchiolin, often in order to help bind the calcium carbonate crystals together. Conchiolin is composed largely of quinone-tanned proteins. Conchiolin (sometimes referred to as conchin) and perlucin are complex proteins which are secreted by a molluscs outer epithelium (the mantle). ... A quinone (or benzoquinone) is either one of the two isomers of cyclohexadienedione or a derivative thereof. ... A representation of the 3D structure of myoglobin, showing coloured alpha helices. ...

Some shells may also contain pigments, which accounts for the fabulous colours of some seashells. These shell pigments may include compounds like pyrroles and porphyrins, which are also proteins. The hard, rigid outer calcium carbonate covering of certain animals is called a shell. ... Pyrrole, or pyrrol, is a heterocyclic aromatic organic compound, a five-membered ring with the formula C4H5N. Pyrroles are components of larger aromatic rings, including the porphyrins of heme, the chlorins and bacteriochlorins of chlorophyll, and the corrin ring of vitamin B12. ... Core porphyrin structure 3D representation A porphyrin is a heterocyclic macrocycle made from 4 pyrrole subunits linked on opposite sides (α position) through 4 methine bridges (=CH-). The macrocycle, therefore, is more aromatic than the related corrins, chlorins (2,3-dihydroporphyrin) and bacteriochlorins (2,3,12,13-tetrahydroporphyrin). ...

The mantle cavity

A mantle skirt is a double fold of mantle that encloses a water space. This space is called the mantle cavity, and it is a central feature of mollusk biology, containing the mollusk's gills, anus, osphradium, nephridiopores, and gonopores. The mantle cavity may function as a respiratory chamber (all mollusks), feeding structure (bivalves), brood chamber (several forms), or locomotory organ (cephalopods and some bivalves). gills of a Smooth Newt Gills inside of a tuna head In aquatic organisms, gills are a respiratory organ for the extraction of oxygen from water and for the excretion of carbon dioxide. ... Female Human Anatomy Male Human Anatomy This article is about the bodily orifice. ... The Osphradium is the olfactory organ in certain molluscs, linked with the respiration organ. ... Nephridiopore is part of the nephridia,an excretory organ found in many organisms such as annelids. ... A genital pore in some invertebrates and especially some insects. ... In animal physiology, respiration is the transport of oxygen from the ambient air to the tissue cells and the transport of carbon dioxide in the opposite direction. ... Orders Subclass Protobranchia Solemyoida Nuculoida Subclass Pteriomorphia - oysters Arcoida Mytiloida Pterioida Subclass Paleoheterodonta - mussels Trigoinoida Unionoida Subclass Heterodonta - clams, zebra mussels Veneroida Myoida Subclass Anomalosdesmata Pholadomyoida Animals of the Class Bivalvia are known as bivalves because they typically have two-part shells, with both parts being more or less symmetrical. ... Orders Subclass Nautiloidea †Plectronocerida †Ellesmerocerida †Actinocerida †Pseudorthocerida †Endocerida †Tarphycerida †Oncocerida †Discosorida Nautilida †Orthocerida †Ascocerida †Bactritida Subclass †Ammonoidea †Goniatitida †Ceratitida †Ammonitida Subclass Coleoidea †Belemnoidea †Aulacocerida †Belemnitida †Hematitida †Phragmoteuthida Neocoleoidea (most living cephalopods) Sepiida Sepiolida Spirulida Teuthida Octopoda Vampyromorphida The cephalopods (Greek plural (kephalópoda); head-foot) are the mollusk class Cephalopoda...

The mantle is highly muscular. In cephalopods it is used to force water through a tubular siphon, the hyponome, to propel the animal quickly through the water. In other mollusks, it is used as a kind of "foot" for locomotion. The hyponome is the organ used by cephalopods for locomotion. ...

The nervous system of cephalopods is the most complex of the invertebrates. The giant nerve fibers of the cephalopod mantle have been a favorite experimental material of neurophysiologists for many years. The Human Nervous System The nervous system of an animal coordinates the activity of the muscles, monitors the organs, constructs and also stops input from the senses, and initiates actions. ... Invertebrate is a term that describes any animal without a spinal column. ... Nerves (yellow) Nerves redirects here. ... Neurophysiology is a part of physiology as a science, which is concerned with the study of the nervous system. ...

See also

• Aperture
• Columnella
• Operculum