第 0714 號，共 1 402 號

Darwin's bark spider

Caerostris darwini

名字的由來： It was named in honour of the naturalist Charles Darwin, on 24 November 2009, exactly 150 years after The Origin of Species was published.1

無害對人無害。不用擔心。

蜘蛛

咬吃：昆蟲

對人的危險: 輕微跟蜜蜂螫差不多或更輕微。對人基本上無害。

Darwin's bark spider is an orb-weaver that builds the largest orb webs ever seen. It lives in the forests of Madagascar, where it hangs its web over rivers and lakes. Scientists found it in 2009, and it has unusually tough silk.1

分布在

Madagascar, found in Andasibe-Mantadia National Park1

非洲

首頁

Builds its web directly above rivers or the water of lakes, a habitat no other spider is known to use. Its webs are large enough to be noticed from a distance.1

長度

2,2 cm (0,9 in)1

最高速度

大約 1,1 km/h（0,68 mph）

在陸地上, 粗略估計

牠吃什麼？

Catches insects, including mayflies, that fly over the water and become caught in its web. One web has been seen holding up to 32 mayflies at a time.1

Darwin's bark spider 的照片 — Darwin's bark spider。照片：Matjazgregoric。 CC BY-SA 4.0, iNaturalist.

怎麼認出牠

Females are largely black, with white hairs on the body and legs.1
The top of the front body section has two pairs of raised humps, one at the sides and one towards the back.1
Females are about 1.8 to 2.2 cm long, while males are around 0.6 cm.1
Males are redder and lighter brown, with white hairs and red, hairless leg segments (femora).1
Webs are very large, up to 2.8 square metres, and are strung over water.1

常被誤認為： Other Caerostris species live in the same region of Madagascar. Darwin's bark spider has clearly separated epigynal chambers (parts of the female's genital plate) with a pair of hooks at the back, which the other species from the region do not have.1

毒液力量

咬

咬的時候，毒液會從毒牙或牙齒出來。

牠對人有多危險？

對人的危險: 輕微跟蜜蜂螫差不多或更輕微。對人基本上無害。

如果牠咬人

清洗咬傷處，用冰敷袋冰敷止痛。如果很痛、疼痛擴散或傷者覺得不舒服，要就醫。

一定要先打緊急電話（112、000、911）。這是一般急救指引，不是醫療建議。急救基本知識

注意安全

絕對不要碰、抓或捉弄野生動物，就算是很小的動物，就算牠看起來在睡覺或已經死了也一樣。
給牠空間。如果遇到了，保持冷靜，慢慢往後退，讓牠自己離開。
如果被牠咬了：保持冷靜，保持不動，打緊急電話（112、000、911）或趕快去醫院。記住牠的樣子，有照片會很有幫助。

牠不是想來抓你。牠用毒液來捕捉食物或保護自己，而且牠更想躲起來。更多安全知識

在世界上的哪裡？

非洲亞洲歐洲北美洲南美洲澳洲與大洋洲

牠有多大？

牠有多長？

大約跟一根迴紋針一樣長可以在 330 秒內跑完 100 公尺（最快的人類需要 9.6 秒）

Darwin's bark spider 跟「你」比起來有多大？

只是在你的瀏覽器裡做算術。什麼都不會儲存，也不會傳送到任何地方。

牠有多快？

一隻陸龜 大約 0,3 km/h (0,19 mph)

Darwin's bark spider 大約 1,1 km/h (0,68 mph)

一個正在走路的人 大約 5 km/h (3,1 mph)

值得知道

小知識

Its silk is the toughest biological material ever studied. It is over ten times tougher than a similar amount of Kevlar.1

Its web is the largest orb web ever observed, covering up to 2.8 square metres. Its bridge lines can span up to 25 metres.1

The spider uses a set of web-building behaviours that are unknown in other spiders. It releases bridge silk into the air so the wind carries it across the water.1

Females are much larger than males, sometimes many times heavier. This is one of the most extreme size differences between the sexes in spiders.1

Flies that feed on its catches have been found living alongside it, and the spider sometimes chases them away.1