Frog
A type of amphibian that undergoes metamorphosis. In days of old, people were captivated by its beautiful call.
A type of amphibian belonging to the Anura order. Around 3,000 species are distributed throughout virtually the entire world, excluding the Antarctic and Arctic regions. Known for going through metamorphoses in their process of growing, in their immature form, they are called tadpoles (otamajakushi in Japanese); the name frog (kaeru) is first used upon their development into adults. Most males have an organ called a vocal sac, a membrane of soft skin below their throats, which functions to amplify the calls they make when trying to attract mates. In terms of shape, the frog’s body can be roughly divided into a head-and-trunk section and four limbs. Frogs’ hindlimbs are particularly well developed, affording them superior jumping power on land, while webs between their digits give them propulsive power in the water. Some species of frogs that live in trees or along mountain streams also have suction pads on the tips of the digits of their hind feet and forefeet.
The meat of large species such as the American bullfrog and tiger frog, with its flavor that is compared to meat like chicken, its soft texture, and high nutritional value, is widely enjoyed as a food. Due to their familiar vertebrate structure and the ease of obtaining them, they are also used as laboratory animals in the field of biology. In Chinese herbal medicine, senso (toad venom), a secretion from the parotid gland of a species of toad, has been used since ancient times for its cardiotonic effect.
Frogs have also had the common name kawazu in Japan since long in the past. In the preface to the Kokin Wakashu (“Collection of Japanese Poems of Ancient and Modern Times,” 905), Japan’s first imperial anthology of waka poetry compiled by Tsurayuki Kino and others, the frog is noted along with the Japanese bush warbler (uguisu) as a living creature endowed with a beautiful call. Among the various species, the Kajika frog, also known as Buerger’s frog, was particularly captivating to people, and in the Edo period (1603–1868), keeping them in cages to enjoy their calls was in vogue. Depictions of frogs also frequently appear in haiku poetry, as seen in the following examples.
furuike ya / kawazu tobikomu / mizu no oto
ancient pond
a frog plunges in
the sound of water
(Basho Matsuo)
yasegaeru / makeru na Issa / kore ni ari
scrawny little frog,
don’t be beaten! I, Issa,
am right here with you
(Issa Kobayashi)
As frogs spawn near water, they have a sensitive awareness of changes in atmospheric pressure, and it is known that they begin to make their calls before rainfall. In Japan, where the culture of rice cultivation has played a central role, particular interest has been given to the croaking of frogs. Frogs also help maintain paddy fields as they prey on harmful insects, and in some regions, they were even considered divine messengers of kami associated with rice fields.
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Tanka and haiku about frogs
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References
- 世界と日本のカエル大図鑑 : 地球のカエル大集合! : 世界のカエル156種類・日本のカエル全43種類松井正文 監修,関慎太郎 写真・文,PHP研究所スキアシガエル、ヤドクガエルなど世界の蛙、156種類と、ヒキガエル、アマガエル等日本の全部の蛙43種の図鑑。(日本図書館協会)
- 両生類・はちゅう類松井正文, 疋田努, 太田英利 指導・執筆,小学館日本で見られる種類全部と世界の代表的な両生類・爬虫類の合わせて約500種を紹介。鳴き声のCD付。(日本図書館協会)
- くらべてわかるカエル : 識別ポイントで見分ける松橋利光 著,山と溪谷社
- 『日本大百科全書(ニッポニカ)』(japanknowledge) 「カエル」の項目
- 『世界大百科事典』(japanknowledge) 「カエル」の項目
- 『日本国語大辞典』(japanknowledge) 「蛙」の項目
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