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The radula (US: / ˈ r æ dʒ ʊ l ə /; pl.: radulae or radulas) [1] is an anatomical structure used by mollusks for feeding, sometimes compared to a tongue. [2] It is a minutely toothed, chitinous ribbon, which is typically used for scraping or cutting food before the food enters the esophagus .
The buccal mass is the first part of the digestive system, and consists of the mouth and pharynx. The mouth includes a radula, and in most cases, also a pair of jaws. The pharynx can be very large, especially in carnivorous species. Many carnivorous species have developed a proboscis, containing the oral cavity, radula, and part of the ...
Muscles that control the radula are shown in brown. The surface of the radula ribbon, with numerous teeth, is shown as a zig-zag line. The odontophore is part of the feeding mechanism in molluscs. It is the cartilage which underlies and supports the radula, a ribbon of teeth. [1] The radula is found in every class of molluscs except for the ...
The radula is taenioglossate, consisting of seven teeth per row: one middle tooth, flanked on each side by one lateral and two marginal teeth. The radula is used to scrape algae and detritus. Phlorotannins in the brown algae Fucus vesiculosus and Ascophyllum nodosum act as chemical defenses against L. littorea. [19]
The massive radula of the scaphopods is the largest such organ relative to body size of any mollusc (among whom, except for the bivalves, the presence of which is a defining characteristic). The remainder of the digestive system consists of a digestive diverticulum , esophagus , stomach , and intestine .
Radula is narrow, with as few as just one tooth per row, in some species asymmetric. Some are secondarily gonochoric , otherwise there is a common spemoviduct either ending with a single opening, connected to a copulatory organ/penial sheath by an external groove, or there is vas deferens and a separate male opening.
The subradular organ is a sensory organ below the grinding mouthparts of some molluscs, specifically the chitons. [1] This organ is involved in chemoreception - that is, in judging the nature of food or the substratum. In this sense, it can be considered a 'smell' or 'taste' organ; food is sensed before each stroke of the radula. [1]
The radula comprises a chitinous ribbon with teeth arranged in transverse and longitudinal rows. [13] The radula continually renews itself during the entire lifespan of a mollusk. The teeth and membrane are continuously synthesized in the radular sac and then shifted forward towards the working zone of the radula.