No. 0619 / 1 402

Mexican beaded lizard

Heloderma horridum

名前について： The genus name Heloderma means "studded skin" in Ancient Greek, and the species name horridum is Latin for "rough" or "rude".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。

毒トカゲ

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 Mexican beaded lizard is a venomous lizard found mainly in Mexico and southern Guatemala. It is one of only a few lizards known to have evolved a true venom delivery system. Its venom is also being studied for possible medicines.1

すんでいる場所

Mexico, from Sonora to Oaxaca, and parts of southern Guatemala (the Pacific and Atlantic drainages).1

北アメリカ

ホーム

It lives mainly in deserts, tropical deciduous forests and thorn scrub, and also in pine-oak forests, from sea level up to 1,500 m. In the wild it is active only from April to mid-November, spending about an hour a day above ground.1

長さ

57 cmから91 cm (1.9 ftから3 ft)1

体重

4 kg (8.8 lb)1

最高速度

時速約2.5 km（時速1.6マイル）

陸で, おおまかな予想

何を食べるの？

It is a specialised nest predator that feeds mainly on bird and reptile eggs. It climbs deciduous trees to search for prey and sometimes eats small birds, mammals, frogs, lizards and insects.1

Mexican beaded lizardの写真 — Mexican beaded lizard。写真：Francisco Farriols Sarabia。 CC BY 4.0, iNaturalist.

見分け方

Black with yellowish spots or bands.1
Small, beadlike scales that do not overlap, which give it its name.1
Stocky body with a broad head.1
Short tail that stores fat, and does not regrow if broken.1
Adults are 57 to 91 cm long.1

よくまちがえられるのは： The Gila monster is its closest relative and looks similar. The Mexican beaded lizard is larger, and its colours are duller, black with yellowish bands.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 is a weak hemotoxin, meaning it attacks blood and tissue. It can cause respiratory failure, which is when breathing fails. In humans, bites cause severe pain that can spread well beyond the bite and last up to 24 hours, along with swelling, weakness, sweating and a rapid drop in blood pressure.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。

Human deaths from its bites are rare. Eight human bites were documented in the past century, and almost all happened when people prodded captive lizards with a finger or bare foot.1

かまれたら

傷口を洗い、その人を落ちつかせて、医療の助けを受けよう。

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？

どれくらい重い？

飼いネコ1匹分の重さ

飼いネコ2匹を鼻からしっぽまでならべた長さバナナ5本をたてにならべた長さだいたい飼いネコくらいの重さ100 mを140秒で走れる（いちばん速い人間は9.6秒）

Mexican beaded lizard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)

Mexican beaded lizard 時速約2.5 km (1.6 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

It is one of only two venomous beaded lizard species, and the only lizards known to have evolved an overt venom delivery system, along with the rest of its genus.1

Some compounds in its venom are being studied for possible treatments of diabetes, Alzheimer's disease and HIV. One of them, exendin-3, is the basis of the drug exenatide.1

The beaded lizard is immune to the effects of its own venom.1

It is larger than the Gila monster, with an average adult weight of 800 g, and large specimens exceed 2,000 g.1

Beaded lizards have forked pink tongues that they use to smell, with the help of a Jacobson's organ.1

Young beaded lizards are rarely seen, as they are believed to spend much of their early lives underground.1

うそ・ほんとう

うそ： The beaded lizard is more venomous than a rattlesnake, can cause lightning strikes with its tail, or can make a pregnant woman miscarry by looking at her.

ほんとう： These beliefs are incorrect. Its venom is weak, and human deaths are rare.1

毒のエキスパート向け

学名: Heloderma horridum
グループ: 毒トカゲ
家族: Helodermatidae2
ならびかえ: Squamata
大陸: 北アメリカ
赤ちゃん: It lays clutches of 2 to 30 eggs in late summer or early fall, and the eggs hatch the following spring or summer.1
野生でのようす: Threatened (Mexican law, category A). Listed on Appendix II of CITES.1
人への危険: 3 / 5: 深刻3