Iguana - Iguana (English spelling)

In a broad sense, it is a general term for lizards belonging to the Iguanidae family of the Squamata order of the Reptilia class, and in a narrow sense, it refers to one of these species. The Iguana iguana , also known as the green iguana, is found in Mexico, the West Indies, Central America, southern Brazil, and Paraguay. Its total length is 1.5 to 1.8 meters, with its long tail making up about two-thirds of its total length. Its entire body is covered with fine scales, and long, spiny decorative scales line its back from the neck to the tail. It has large fins on its pharynx, but the males' are larger, and during the breeding season, they spread them out and shake their heads up and down to display their courtship and territorial claims to females. It lives in the trees near water in tropical rainforests, and when it sees a hawk or other animal, it immediately jumps into the water to hide. In the water, they swim skillfully by keeping their limbs close to their sides and twisting their tails. They are also fast on land. They feed on plant matter such as leaves and fruit, but when young they will also catch insects. Females lay around 30-40 eggs on land at a time, and it is said that local Indians remove the eggs for food from the captured females, sew up their abdomens, and release them into the forest to collect more eggs. The Iguanidae is a large group consisting of about 50 genera and 700 species, and all of them are found in the Americas, with two genera living in Madagascar and one in Polynesia (two species including the Fiji iguana , Brachylophus fasciatus ).

[Takahiro Matsui]

Source: Shogakukan Encyclopedia Nipponica About Encyclopedia Nipponica Information | Legend

広義には爬虫(はちゅう)綱有鱗目(ゆうりんもく)イグアナ科に属するトカゲの総称で、狭義にはそのうちの1種をさす。種としてのイグアナIguana iguanaはグリーンイグアナともよばれ、メキシコ、西インド諸島、中央アメリカからブラジル南部、パラグアイに分布する。全長1.5～1.8メートル、尾が長く全長の3分の2ほどを占める。全身が細かい鱗(うろこ)に覆われ、頸部(けいぶ)から尾部にかけて背中線上に長い棘(とげ)状の飾り鱗が並ぶ。咽頭(いんとう)部には大きなひれ飾りが発達するが、雄のものが大きく、繁殖期にはこれを広げて頭を上下に振り、雌に対する求愛や縄張り（テリトリー）争いのディスプレーを行う。熱帯降雨林の水辺の樹上にすみ、タカなどの姿をみるとすぐに水中に飛び降りて隠れる。水中では、四肢を体側につけ、尾をくねらせて巧みに泳ぐ。地上での走行もすばやい。餌(えさ)は木の葉や果実など植物質のものであるが、幼時には昆虫もとらえる。雌は一度に30～40個ほどを地上に産卵するが、現地のインディオは、とらえた雌から食用のための卵を取り出し、腹部を縫ってから森に放ち、ふたたび卵を得ようとするといわれる。イグアナ科Iguanidaeは約50属700種に及ぶ大きなグループで、マダガスカルに2属、ポリネシアに1属（フィジーイグアナBrachylophus fasciatusなど2種）が生息する以外は、すべてアメリカ大陸に分布する。

［松井孝爾］

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