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Spider-tailed horned viper

Pseudocerastes urarachnoides

名前について： The scientific name comes from Ancient Greek words meaning tail, spider and 'like', because of its spider-like tail tip.1

お医者さんが必要命にかかわることはまれだけど、かまれたらお医者さんへ。

クサリヘビのなかま

かむ食べもの：肉

人への危険: 深刻かまれたらお医者さんへ。死ぬことはとてもまれだよ。

The spider-tailed horned viper is a venomous snake with a tail tip that looks like a spider. It lives only in the mountains of western Iran and the nearby eastern part of Iraq. It wiggles its tail to lure birds close enough to catch.1

すんでいる場所

Western Iran and the eastern part of Iraq, near the Iran-Iraq border, mainly on the western side of the Zagros Mountains1

アジア

ホーム

It lives at higher elevations, mostly on rocky ground made of gypsum, and prefers deep cracks and holes in the rock. These spots trap humidity and moisture during hot summers. During the day it is most often found in the shade of a shrub.1

長さ

60 cm (2 ft)3

ふつうのおとなのサイズ

最高速度

時速約3.4 km（時速2.1マイル）

陸で, おおまかな予想

何を食べるの？

It eats birds, including the Isabelline shrike and several warbler species. It waves the tip of its tail in a figure-of-eight pattern to lure insect-eating birds within striking range.1

Spider-tailed horned viperの写真 — Spider-tailed horned viper。写真：Omid Mozaffari。 Public domain, Wikimedia Commons.

見分け方

The scales above each eye rise up into small horns.1
About 16 to 17 scales sit between the horns.1
The bulb-shaped tail tip is bordered by long, drooping scales that look like spider legs.1
The scales on the body are rougher than those of other species in its genus.1
It has 15 pairs of subcaudal scales (the scales on the underside of the tail).1

よくまちがえられるのは： It looks very similar to other Pseudocerastes vipers in the region, especially around the head. The unusual, spider-like tail tip is the feature that sets it apart.1

毒パワー

かむ

かむときに、毒が牙や歯から出るよ。

その毒（かむ・刺す毒）はどうなるの？

Its venom mainly acts as a cytotoxin, which destroys cells across a wide variety of cell types, and it has minor neurotoxic effects, which attack the nerves. It is a procoagulant, meaning it makes blood clot, and reports describe clotting in about 13 seconds. The venom affects birds most strongly, and also affects mammals and amphibians. A 2021 study by Brouw found it has a coagulant effect on humans and affects Factor X, a protein needed for blood clotting.1

人にとってどれくらい危険？

人への危険: 深刻かまれたらお医者さんへ。死ぬことはとてもまれだよ。

No human bite has ever been recorded in the wild. How severe its effects would be on people is not known.1

かまれたら

その人をじっとさせて落ちつかせ、かまれた手足を心臓と同じ高さにして、指輪やきついものをはずし、急いで病院へ。

まず必ず救急番号（112、000、911）に電話しよう。これは一般的な応急手当の案内で、医療のアドバイスではないよ。応急手当の基本

安全に過ごそう

野生の動物には、小さくても、ねているように見えても、死んでいるように見えても、ぜったいにさわったり、つかまえたり、からかったりしないこと。
近づかないで。出会ったら落ちついて、ゆっくりあとずさりして、そのまま行かせてあげよう。
かまれたら：落ちついて、じっとして、救急番号（112、000、911）に電話するか、急いで病院へ行こう。見た目をおぼえておいてね。写真があると役に立つよ。

きみをねらっているわけじゃないよ。毒はエサをとったり身を守ったりするために使うだけで、本当はかくれていたいんだ。安全に過ごすためにもっと知ろう

世界のどこ？

アフリカアジアヨーロッパ北アメリカ南アメリカオーストラリアとオセアニア

どれくらい大きい？

どれくらい長い？

バナナ3本をたてにならべた長さ100 mを110秒で走れる（いちばん速い人間は9.6秒）

Spider-tailed horned viperは、きみとくらべてどれくらい大きい？

ブラウザで計算しているだけ。何も保存されないし、どこにも送られないよ。

どれくらい速い？

リクガメ 時速約0.3 km (0.19 mph)

Spider-tailed horned viper 時速約3.4 km (2.1 mph)

歩いている人 時速約5 km (3.1 mph)

知っておく価値あり

データ

Its tail is moved in a figure-of-eight pattern, and it moves faster when birds are nearby. Field studies have confirmed that this is a lure and not random movement.1

Footage of it luring migrating birds appears in the Asia episode of the BBC series Seven Worlds, One Planet, narrated by David Attenborough.1

A digested lark was found in the stomach of one of the specimens used to describe the species, supporting the idea that the tail lures birds.1

Its tail tip is a form of aggressive mimicry, where a predator looks like something else to attract its prey.1

Several other snakes, such as the sidewinder and the green tree python, also use the tip of their tail as a lure, but none has the elongated scales that look like arthropod legs.1

A specimen collected in 1968 was first identified as a Persian horned viper. It was only recognised as a separate species and described in 2006.1

うそ・ほんとう

うそ： The strange tail tip was caused by a parasite, a deformity or a tumour.

ほんとう： Early specimens were thought to have a damaged tail tip. In fact, the spider-like tail is a natural feature that the snake uses to lure birds.1