9 Invertebrates-Low

Invertebrates Written by Brooke Bessesen

无脊椎动物布鲁克·贝森著

Introduction Invertebrates are "spineless" animals. That means they have no backbone. Feel the bumps in the middle of your back. The bones of your backbone, or spine are called vertebrae (VER-tuh-bray). Animals with a spine are called vertebrates. You are a vertebrate. But most animals are invertebrates.

无脊椎动物是“没有脊椎”的动物。 这意味着他们没有骨气。 感受背部中间的隆起。 脊椎骨(VER-tuh-bray)。 有脊椎的动物叫做脊椎动物。 你是脊椎动物。但是大多数动物都是无脊椎动物。

What Do Invertebrates Have in Common? Invertebrates have many things in common. You already know they have no spine. But they have other things in common, too: Like all animals, invertebrates have more than one cell. All invertebrates move their body in some way. Invertebrates need oxygen, but they do not breathe as we do.

无脊椎动物有什么共同之处? 无脊椎动物有很多共同之处。 你已经知道他们没骨气了。 但它们也有其他共同点:像所有动物一样，无脊椎动物有不止一个细胞。 所有无脊椎动物都以某种方式移动它们的身体。 无脊椎动物需要氧气，但它们不像我们一样呼吸。

Most invertebrates have symmetry. That means the sides of their body look alike. Invertebrates can't make their own heat. They are cold-blooded. Most invertebrates make young with sperm from males and eggs from females. Invertebrates eat to stay alive. In this book, you will learn about some groups of invertebrates. You will find out how they move and eat.

大多数无脊椎动物都有对称性。 也就是说他们身体的两边长得很像。 无脊椎动物不能自己产生热量。 他们是冷血动物。大多数无脊椎动物用雄性的精子和雌性的卵子繁殖后代。 无脊椎动物吃东西是为了生存。 在这本书中，你将了解一些无脊椎动物群体。 你会发现它们是如何移动和进食的。

Classifying Invertebrates Invertebrates have things in common, but they are very different, too. A fruit fly is smaller than a grain of rice. A giant squid can be as long as a bus. Centipedes eat worms. Butterflies drink from flowers. Bees fly, and crabs crawl. Earth has many, many kinds of invertebrates!

无脊椎动物有共同点，但也有很大的不同。 果蝇比一粒米还小。 巨型乌贼可以和一辆公共汽车一样长。 蜈蚣吃虫子。蝴蝶从花中饮水。 蜜蜂会飞，螃蟹会爬。 地球上有很多很多种类的无脊椎动物!

Scientists classify, or group, animals by the things they have in common. Animals are either vertebrates or invertebrates. Each kind is made up of smaller groups. Read on to learn about some groups of invertebrates. VERTEBRATES Mammals Birds Reptiles Amphibians Fish Invertebrates Poriferans sponges Cnidarians sea jellies corals sea anemones Echinoderms sea stars sea urchins sand dollars Mollusks octopuses squids snails clams Annelids earthworms Arthropods insects spiders lobsters millipedes These are the invertebrate groups covered in this book

科学家们根据动物的共同之处对它们进行分类。 动物不是脊椎动物就是无脊椎动物。 每一种都由更小的群体组成。 继续读下去，了解一些无脊椎动物。 脊椎动物哺乳动物鸟类爬行动物两栖动物鱼类无脊椎动物多孔动物海绵刺皮动物海水母珊瑚海葵棘皮动物海星海胆沙美元软体动物章鱼鱿鱼蜗牛蛤节肢动物蚯蚓节肢动物昆虫蜘蛛龙虾千足虫这些都是这本书中涉及的无脊椎动物类群