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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 gills, anus, osphradium, nephridiopores, and gonopores. The mantle cavity functions as a respiratory chamber in most mollusks. In bivalves it is usually ...
Mollusca is a phylum of protostomic invertebrate animals, whose members are known as molluscs or mollusks [a] (/ ˈ m ɒ l ə s k s /). Around 76,000 extant species of molluscs are recognized, making it the second-largest animal phylum after Arthropoda . [ 5 ]
The mantle is roughly circular in outline, and is covered with pustules; the ground colour of the mantle varies, usually being orange or brownish, and the pustules are usually white. The mollusc does not elongate when crawling and the location of the head is revealed when it thrusts out its rolled rhinophores from beneath the
Mantle of giant clam with light-sensitive spots, which detect danger and cause the clam to close. Tridacna gigas, the giant clam, is the best-known species of the giant clam genus Tridacna. Giant clams are the largest living bivalve molluscs. Several other species of "giant clam" in the genus Tridacna are often misidentified as Tridacna gigas.
The taxonomic term Bivalvia was first used by Linnaeus in the 10th edition of his Systema Naturae in 1758 to refer to animals having shells composed of two valves. [3] More recently, the class was known as Pelecypoda, meaning "axe-foot" (based on the shape of the foot of the animal when extended).
Some species brood the eggs within the mantle cavity, and the species Callistochiton viviparus even retains them within the ovary and gives birth to live young, an example of ovoviviparity. The egg has a tough spiny coat, and usually hatches to release a free-swimming trochophore larva, typical of many other mollusc groups. In a few cases, the ...
diverticulum (mollusc) style (zoology) Respiratory system of gastropods. ctenidium (mollusc) cerata. cnidosac; pneumostome; siphon (mollusc) circulatory system of gastropods; excretory system of gastropods. pseudofeces; reproductive system of gastropods. apophallation; Love dart; number of other genital structures: reproductive system of ...
The aperture is an opening in certain kinds of mollusc shells: it is the main opening of the shell, where the head-foot part of the body of the animal emerges for locomotion, feeding, etc. The term aperture is used for the main opening in gastropod shells, scaphopod shells, and also for Nautilus and ammonite shells.