A vertebrate is an animal that has a backbone — a spine made of small linked bones. Fish, frogs, snakes, birds and every mammal, including you, are vertebrates. Animals without one, like insects, worms, jellyfish and octopuses, are invertebrates, and they are actually the huge majority: vertebrates are a small minority of all animal species, even though they are the big, familiar animals we notice.

A vertebrate is an animal that has a backboneVertebrate是指有脊椎的動物——a spine made of small linked bones由一小塊一小塊骨頭連接起來的脊柱。Fish, frogs, snakes, birds and every mammal, including you, are vertebrates魚、青蛙、蛇、鳥，還有包括你在內的每一種哺乳類，都是vertebrates。Animals without one, like insects, worms, jellyfish and octopuses, are invertebrates沒有脊椎的動物，像昆蟲、蟲子、水母和章魚，叫做invertebrates，and they are actually the huge majority而且牠們其實才是絕大多數：vertebrates are a small minority of all animal speciesvertebrates只占所有動物物種裡的一小部分，even though they are the big, familiar animals we notice儘管牠們是我們注意到的那些又大又熟悉的動物。

The word works both as a noun ('a vertebrate') and as an adjective ('vertebrate animals', 'the vertebrate eye'). It belongs to biology class, nature documentaries and science writing; you would not use it over dinner unless you were talking about animals on purpose.

The word works both as a noun ('a vertebrate')這個字可以當名詞用（a vertebrate一種脊椎動物），and as an adjective ('vertebrate animals', 'the vertebrate eye')也可以當形容詞用（vertebrate animals脊椎動物、the vertebrate eye脊椎動物的眼睛）。It belongs to biology class, nature documentaries and science writing它屬於生物課、自然紀錄片和科學寫作的用字；you would not use it over dinner unless you were talking about animals on purpose你不會在吃飯時用到它，除非你是刻意在講動物。

One useful thing to know: having a backbone is only the headline feature. Biologists group vertebrates together because they share a whole package — a skull around the brain, an internal skeleton that grows with the body, and a nerve cord running along the back. That internal skeleton is why vertebrates can get large: a beetle's outside shell cannot be scaled up, but a bone frame can.

One useful thing to know: having a backbone is only the headline feature有一件實用的事要知道：有脊椎只是最顯眼的特徵而已。Biologists group vertebrates together because they share a whole package生物學家會把vertebrates歸在一起，是因為牠們共有一整套特徵——a skull around the brain包住腦的頭骨、an internal skeleton that grows with the body會隨身體一起長大的內骨骼，and a nerve cord running along the back還有一條沿著背部延伸的神經索。That internal skeleton is why vertebrates can get large就是那副內骨骼，讓vertebrates能夠長得很大：a beetle's outside shell cannot be scaled up甲蟲的外殼沒辦法等比例放大，but a bone frame can但一副骨架可以。