4 Extreme Amphibians-Low

Extreme Amphibians FOCUS Question What makes some amphibians unusual?

极端两栖动物焦点问题是什么让一些两栖动物与众不同?

What Are Amphibians? Have you ever been to a pond? Did you see a frog A frog is one kind of amphibian (am-FIH-bee-in). Amphibians lay eggs in water. When the eggs hatch, the young may not look like their parents. Many amphibians start off as tadpoles. The tadpoles live in water and have gills. Adult amphibians have lungs and can live in water or on land. You may know a lot about frogs. But did you know that some amphibians are see-through? Some have no legs or no eyes. Some can even freeze in the winter! These are extreme amphibians!

什么是两栖动物?你去过池塘吗? 你看到青蛙了吗?青蛙是一种两栖动物。 两栖动物在水中产卵。 当蛋孵化时，幼崽可能看起来不像它们的父母。 许多两栖动物一开始是蝌蚪。 蝌蚪生活在水里，有鳃。 成年两栖动物有肺，可以生活在水里或陆地上。 你可能对青蛙很了解。 但你知道有些两栖动物是透明的吗? 有些没有腿或眼睛。 有些甚至会在冬天结冰!这些是极端的两栖动物!

Big and Small Frogs The most common amphibians are frogs. Frogs are usually small enough to fit in your hand. One frog is much smaller. It is only the size of a fly! It is the world's smallest vertebrate. It lives in the rainforests of New Guinea. It is so small that scientists didn't discover it until 2009. Other frogs can be enormous. The Goliath frog is longer than your forearm. It can weigh over 3 kilograms (7 lb.). It is big enough to eat mice! This huge frog lives in tropical forests of western Africa.

最常见的两栖动物是青蛙。 青蛙通常很小，可以握在手里。 一只青蛙要小得多。它只有一只苍蝇那么大!它是世界上最小的脊椎动物。 它生活在新几内亚的雨林里。 它是如此之小，以至于科学家直到2009年才发现它。 其他青蛙可能很大。 歌利亚蛙比你的前臂还长。 它的重量可以超过3公斤(7磅)。 它大得可以吃老鼠!这种巨大的青蛙生活在西非的热带森林里。

Hot and Cold Frogs Some frogs live in deserts. The water- holding frog lives in parts of Australia that are dry for most of the year. When it finally rains, the frog soaks up water. The outer layer of its skin gets loose and fills up like a water balloon. The frog digs a burrow and can live off this water for months. What do frogs do in winter, when water freezes solid? Some frogs freeze up! Alaskan wood frogs become almost solid during winter. They have special blood that can freeze without hurting their body. When spring comes, they thaw out and hop away.

冷热青蛙有些青蛙生活在沙漠里。 这种持水蛙生活在澳大利亚大部分时间都干燥的地区。 终于下雨了，青蛙把水都吸干了。 它的皮肤外层会松弛，像水球一样充满。 青蛙挖了一个洞，可以靠水生活几个月。 当水在冬天结冰时，青蛙会做什么? 有些青蛙冻住了!阿拉斯加林蛙在冬天几乎变得结实。 他们有特殊的血液，可以冻结而不伤害他们的身体。 当春天来临时，它们就会解冻，然后跳着离开。

Poisonous Frogs Many animals eat frogs. Some frogs fight back, but not with teeth or claws. They have poisonous skin. A single poison dart frog could kill ten people. Luckily, these frogs are easy to spot. They are candy colored. They can be blue, red, green, orange, or yellow. The bright color warns predators that might try to eat them, It says, "Stay away!" Do You Know? Poison dart frogs get their poison from their diet. They eat ants They use chemicals from the ants sting to make their own poison. If they don't eat ants the frogs are not poisonous.

许多动物吃青蛙。 有些青蛙会反击，但不是用牙齿或爪子。 他们的皮肤有毒。一只毒箭蛙可以杀死十个人。 幸运的是，这些青蛙很容易被发现。 它们是糖果色的。它们可以是蓝色、红色、绿色、橙色或黄色。 鲜艳的颜色警告可能试图吃掉它们的捕食者，它说:“远离!”你知道吗? 毒箭蛙从它们的食物中获取毒素。 它们用蚂蚁蛰出的化学物质制造自己的毒药。 如果它们不吃蚂蚁，青蛙是无毒的。

Strange Salamanders Salamanders and newts are shaped like lizards. Like all amphibians, they lay eggs in water. The young live in the water and breathe through gills. Some adult salamanders live on land. They have lungs and breathe air Others stay in the water their entire lives. The largest amphibian on Earth is a salamander. The Chinese giant salamander can weigh 50 kilograms (110 lb.). It can grow to be 1.4 meters (4.7 ft.) long. This salamander lives in cold mountain streams, where it hunts fish. It stays in the water its entire life. Math Moment How many Goliath frogs would it take to weigh more than one Chinese giant salamander?

蝾螈和蝾螈的形状像蜥蜴。 像所有的两栖动物一样，它们在水中产卵。 幼鱼生活在水里，用鳃呼吸。 一些成年蝾螈生活在陆地上。 它们有肺和呼吸空气，其他的则一生都呆在水里。 地球上最大的两栖动物是蝾螈。 中国大鲵体重可达50公斤(110磅)。 它可以长到1.4米(4.7英尺)长。 这种蝾螈生活在寒冷的山涧中，在那里捕鱼。 它一生都呆在水里。 需要多少只歌利亚蛙才能比一只中国大鲵重?