Radula

Japanese: Radula

…A part of the digestive system of an animal; a hard organ that mainly bites and crushes food. In invertebrates, teeth are found in various places in various animals, such as the mouths of polychaetes, rotifers, and insects, the stomach of crayfish, the radula of mollusks, and Aristotle's lantern of sea urchins. These are made of chitin, silicic acid, and calcium carbonate, and share the hard quality that is suitable for taking in and digesting food. …

From [Moss on leaves]

…They develop in warm and humid regions, and many species have diversified in the tropics, but they are also quite common in lowland valleys in southern Japan. There are few mosses or hornworts among leaf mosses, and most are liverworts, especially in the genus Cololejeunea (of the family Cololejeunea), the genus Leptolejeunea (of the family Leptolejeunea), and the genus Radula (of the family Leptolejeunea). These leaf mosses are generally adapted to the special environment of leaves, such as having a very small plant body, a short period before they become reproductive, a bag-like structure that stores water in parts of the leaf, well-developed suction organs that allow them to attach to smooth surfaces, and the production of disk-shaped gemmae that are stable on a flat surface. …

*Some of the terminology that mentions "Radula" is listed below.

Source | Heibonsha World Encyclopedia 2nd Edition | Information

Japanese:

…動物の消化器の一部で，おもに食物のかみ切りや，かみ砕きをする硬い器官。無脊椎動物では，多毛類，ワムシ類，昆虫類などの口，ザリガニの胃，軟体動物の歯舌（しぜつ）radula，ウニのアリストテレスの提灯（ちようちん）など，さまざまな動物のさまざまな場所に歯と呼ばれるものがある。これらはキチン，ケイ酸，炭酸石灰などでできているため，食物の取りこみや消化に適した硬い質を共通してもっている。…

【葉上苔】より

…温暖で湿潤な地域に発達し，熱帯では多種に分化しているが，日本の南部でも低地の谷間などにかなり多い。葉上苔には蘚（せん）類やツノゴケ類は少なく，大部分が苔（たい）類で，特にクサリゴケ科のヒメクサリゴケ属Cololejeunea，カビゴケ属Leptolejeunea，ケビラゴケ科のケビラゴケ属Radulaなどに多い。これらの葉上苔は一般に，植物体が微小である，生殖可能になるまでの期間が短い，葉の一部が水を蓄える袋状の構造をつくる，平滑な表面に付着するための吸着器官が発達している，平面で安定しやすい円盤状の無性芽をつくるなど，葉上という特殊な環境に対する適応を遂げている。…

※「Radula」について言及している用語解説の一部を掲載しています。

出典｜株式会社平凡社世界大百科事典第２版について | 情報

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