第 1118 號，共 1 402 號

By-the-wind sailor

Velella velella

名字的由來： Its common name refers to its small sail, which catches the wind and carries the animal across the sea.1

無害對人無害。不用擔心。

水母和會螫人的海洋生物

會螫人的觸手吃：肉

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。

The by-the-wind sailor is a small, deep blue animal that floats on the surface of the open ocean. It is not a single creature but a colony of tiny linked animals, and it moves by catching the wind with a small stiff sail. Its stinging tentacles are generally harmless to people, but they can irritate the skin.1

分布在

Warm and temperate waters of all the world's oceans1

太平洋, 大西洋, 印度洋, 地中海, 南冰洋, 南極洲

首頁

It lives at the surface of the open ocean, floating with its sail above the water and its polyps hanging about 1 cm below. Under certain winds, thousands can be washed up on beaches, such as along the West Coast of North America, the west coast of Ireland and Hayle in Cornwall, England.1

長度

7 cm (2,8 in)1

最高速度

大約 1 km/h（0,62 mph）

游泳, 粗略估計

牠吃什麼？

It eats mostly plankton. It catches prey with tentacles that hang down in the water and bear stinging cells called nematocysts.1

By-the-wind sailor 的照片 — By-the-wind sailor。照片：Niki Hubbard。 CC BY 4.0, iNaturalist.

怎麼認出牠

Usually deep blue in colour1
A small, stiff sail projects above the water1
Most are less than about 7 cm long1
Tentacles hang down into the water below the float1

毒液力量

會螫人的觸手

有東西碰到時，成千上萬個小小的刺細胞就會發射。

牠的毒液有什麼作用？

Its nematocysts contain toxins that are effective against its prey, which are mostly plankton. The nematocysts are relatively benign to humans, but each person may respond differently to the toxin. Contact may cause irritation to exposed skin.1

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。

It is relatively harmless to humans. Its main effect is possible skin irritation after contact. Mass strandings can leave large numbers of dying and rotting animals on beaches.1

如果牠螫人

離開水裡，把觸手拿掉（戴手套或用布）。
熱帶箱形水母：在螫傷處倒醋至少 30 秒，求救，並準備好做心肺復甦術（CPR）。藍瓶水母和大多數其他水母：用海水沖洗，再用熱水止痛。

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。
如果被牠螫了：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南極洲太平洋大西洋印度洋南冰洋地中海

牠有多大？

牠有多長？

跟 2 塊玩具積木排成一排一樣長可以在 180 秒內游完一座大游泳池（50 公尺）

By-the-wind sailor 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？

一隻花園蝸牛 大約 0,05 km/h (0,03 mph)

By-the-wind sailor 大約 1 km/h (0,62 mph)

一個正在游泳的人 大約 3 km/h (1,9 mph)

值得知道

小知識

Its floating colonies are mirror images of each other, either 'left-handed' or 'right-handed', and this affects where they drift. In the northern Pacific, one form tends to drift to North America and the other to eastern Asia, such as Japan.1

Each blue 'animal' with a sail is really a colony of linked polyps that share food through a canal system.1

Each colony is either all male or all female.1

Its sail is not a fin. It works like a sail, so the animal tends to drift downwind at a small angle to the wind.1

Its tiny jellyfish carry zooxanthellae, single-celled organisms that use sunlight to provide energy, a feature also found in corals.1

It has no means of moving other than its sail, so it depends on prevailing winds, and mass strandings on beaches happen in many parts of the world.1

破解迷思

迷思： Each blue sail is a single, simple animal.

真相： Each apparent individual is a colony of many connected polyps that share food and divide the work between feeding, reproductive and protective polyps.1

給毒液專家

學名: Velella velella
類群: 水母和會螫人的海洋生物
家人: Porpitidae2
排序: Anthoathecata
各大洲: 太平洋, 大西洋, 印度洋, 地中海, 南冰洋, 南極洲, 海洋
寶寶: Each colony's feeding polyps (gonozooids) bud off thousands of tiny jellyfish, each about 1 mm wide, over several weeks. These develop into a free-swimming larva called a conaria, which grows into a new floating colony.1
對人的危險: 1 / 5: 輕微3