The mantle (also known by the

Latin Latin (, or , ) is a classical language belonging to the Italic branch of the Indo-European languages. Latin was originally a dialect spoken in the lower Tiber area (then known as Latium) around present-day Rome, but through the power of the ...

word pallium meaning mantle, robe or cloak, adjective pallial) is a significant part of the anatomy of molluscs: it is the

dorsal Dorsal (from Latin ''dorsum'' ‘back’) may refer to: * Dorsal (anatomy), an anatomical term of location referring to the back or upper side of an organism or parts of an organism * Dorsal, positioned on top of an aircraft's fuselage * Dorsal c ...

body wall which covers the visceral mass and usually protrudes in the form of flaps well beyond the visceral mass itself. In many species of molluscs the epidermis of the mantle secretes calcium carbonate and

conchiolin Conchiolins (sometimes referred to as conchins) are complex proteins which are secreted by a mollusc's outer epithelium (the mantle). These proteins are part of a matrix of organic macromolecules, mainly proteins and polysaccharides, that ass ...

, and creates a

shell Shell may refer to: Architecture and design * Shell (structure), a thin structure ** Concrete shell, a thin shell of concrete, usually with no interior columns or exterior buttresses ** Thin-shell structure Science Biology * Seashell, a hard o ...

. In

sea slug Sea slug is a common name for some marine invertebrates with varying levels of resemblance to terrestrial slugs. Most creatures known as sea slugs are gastropods, i.e. they are sea snails (marine gastropod mollusks) that over evolutionary time ...

s there is a progressive loss of the shell and the mantle becomes the dorsal surface of the animal. The words mantle and pallium both originally meant cloak or cape, see

mantle (vesture) A mantle ( el, μανδύας, translit=mandyas; Church Slavonic: мантия, ''mantiya'') is an ecclesiastical garment in the form of a very full cape that extends to the floor, joined at the neck, that is worn over the outer garments. Especia ...

. This anatomical structure in molluscs often resembles a cloak because in many groups the edges of the mantle, usually referred to as the ''mantle margin'', extend far beyond the main part of the body, forming flaps, double-layered structures which have been adapted for many different uses, including for example, the siphon.

Mantle cavity

The ''mantle cavity'' is a central feature of molluscan biology. This cavity is formed by the mantle skirt, a double fold of mantle which encloses a water space. This space contains the mollusk's

gill A gill () is a respiratory organ that many aquatic organisms use to extract dissolved oxygen from water and to excrete carbon dioxide. The gills of some species, such as hermit crabs, have adapted to allow respiration on land provided they are ...

s, anus,

osphradium The osphradium is a pigmented chemosensory epithelium patch in the mantle cavity present in six of the eight extant classes of molluscs (it is absent in the scaphopoda and monoplacophora; among cephalopoda, only the nautilus has what appears to be ...

nephridiopore A nephridiopore is part of the nephridium, an excretory organ found in many organisms, such as flatworms and annelids. Polychaetes typically release their gametes into the water column using nephridiopores. Nephridia are homologous to nephrons o ...

s, and

gonopore A gonopore, sometimes called a gonadopore, is a genital pore in many invertebrates. Hexapods, including insects have a single common gonopore, except mayflies, which have a pair of gonopores. More specifically, in the unmodified female it is t ...

s. The mantle cavity functions as a

respiratory The respiratory system (also respiratory apparatus, ventilatory system) is a biological system consisting of specific organs and structures used for gas exchange in animals and plants. The anatomy and physiology that make this happen varies gre ...

chamber in most mollusks. In bivalves it is usually part of the feeding structure. In some mollusks the mantle cavity is a brood chamber, and in cephalopods and some bivalves such as scallops, it is a

locomotory organ Animal locomotion, in ethology, is any of a variety of methods that animals use to move from one place to another. Some modes of locomotion are (initially) self-propelled, e.g., running, swimming, jumping, flying, hopping, soaring and gliding. Th ...

. The mantle is highly muscular. In cephalopods the contraction of the mantle is used to force water through a tubular siphon, the

hyponome A siphon is an anatomical structure which is part of the body of aquatic molluscs in three Class (biology), classes: Gastropoda, Bivalvia and Cephalopoda (members of these classes include saltwater and freshwater snails, clams, octopus, squid and ...

, and this propels the animal very rapidly through the water. In gastropods it is used as a kind of "foot" for locomotion over the surface. In ''

Patella The patella, also known as the kneecap, is a flat, rounded triangular bone which articulates with the femur (thigh bone) and covers and protects the anterior articular surface of the knee joint. The patella is found in many tetrapods, such as ...

'' the foot includes the entire ventral surface of the animal. The foot of the

Bivalvia Bivalvia (), in previous centuries referred to as the Lamellibranchiata and Pelecypoda, is a class of marine and freshwater molluscs that have laterally compressed bodies enclosed by a shell consisting of two hinged parts. As a group, biva ...

is a fleshy process adapted by its form to digging rather than to locomotion.

Formation of mollusc shell

In shelled molluscs, the mantle is the organ that forms the shell, and adds to the shell to increase its size and strength as the animal grows. Shell material is secreted by the ectodermic (

epithelial Epithelium or epithelial tissue is one of the four basic types of animal tissue, along with connective tissue, muscle tissue and nervous tissue. It is a thin, continuous, protective layer of compactly packed cells with a little intercell ...

) cells of the mantle tissue."integument (molluscs)." Encyclopædia Britannica. 2009.

Encyclopædia Britannica 2006 Ultimate Reference Suite DVD An encyclopedia (American English) or encyclopædia (British English) is a reference work or compendium providing summaries of knowledge either general or special to a particular field or discipline. Encyclopedias are divided into articles ...

Mantle of gastropods

The mantle of many gastropods is usually fully or partially hidden inside the

gastropod shell The gastropod shell is part of the body of a gastropod or snail, a kind of mollusc. The shell is an exoskeleton, which protects from predators, mechanical damage, and dehydration, but also serves for muscle attachment and calcium storage. Some ...

. File:Cypraea chinensis with partially extended mantle.jpg, The marine gastropod '' Cypraea chinensis'', the Chinese cowry, showing its partially extended mantle. File:Cypraea chinensis with fully extended mantle.jpg, ''Cypraea chinensis'' with its mantle fully extended. File:SnailWynaad.jpg, The mantle of the land snail '' Indrella ampulla'' is off-white in color and partly visible under the shell. The head and foot are red, and the foot fringe is off-white with narrow black lines. File:BEP 7909-1.jpg, The mantle of the nudibranch ''

Felimida purpurea ''Felimida purpurea'' is a species of colourful sea slug, a dorid nudibranch, a marine gastropod mollusc Mollusca is the second-largest phylum of invertebrate animals after the Arthropoda, the members of which are known as molluscs or mo ...

'' has a marginal line of orange-yellow colour. In species where the shell is small compared to the size of the body, more of the mantle shows. Shell-less slugs have the mantle fully visible. The dorsal surface of the mantle is called the notum, while the ventral surface of the mantle is called the hyponotum. In the family

Philomycidae Philomycidae are a family of air-breathing land slugs (snails without shells or with only shell remnants). They are terrestrial pulmonate gastropod mollusks in the superfamily Arionoidea (according to the taxonomy of the Gastropoda by Bouc ...

, the mantle covers the whole back side of the body.Tsai C.-L. & Wu S.-K. (2008)
PDF "A New ''Meghimatium'' Slug (Pulmonata: Philomycidae) from Taiwan".
''

Zoological Studies ''Zoological Studies'' is a peer-reviewed open access scientific journal covering zoology, with focuses on animal behavior, comparative physiology, evolution, ecology, systematics and biogeography. It is published by the Biodiversity Researc ...

'' 47(6): 759-766. File:Bielzia coerulans-3.jpg, The mantle and the head of this slug '' Bielzia coerulans'' is smooth, while the rest of the body is tubercled. File:Megapallifera mutabilis.jpg, ''

Megapallifera mutabilis ''Megapallifera mutabilis'', common name the changeable mantleslug, is a species of air-breathing land slug, a terrestrial pulmonate gastropod mollusk in the family Philomycidae. It eats primarily algae, and lives in live trees such as American b ...

'' from

shows enormously developed mantle

References

{{Gastropod anatomy Mollusc anatomy Cephalopod zootomy

Mantle cavity

Formation of mollusc shell

Mantle of gastropods

See also

References