Animal Armor A robber crab grabs the trunk of a palm tree.


It digs its toes into the bark as it climbs higher and higher. With its giant claws and hard, thick shell,


this crab looks like a rough predator. Yet it mostly eats plants. It climbs the tree to snip coconuts. T ud! A coconut falls to the ground. T e crab crawls aſt er it. With one pointy leg, it pokes a hole in the coconut. T en it tears out the soſt , white coconut meat. Crabs belong to the phylum Arthropoda.


T e name means “jointed foot.” Arthropods make up the largest and most varied group of invertebrates. T is group includes shrimps, spiders, centipedes, and every kind of insect. Some live in the sea. Others live on land. T ese animals swim, crawl, or fly. Yet they all have some things in common.


T eir legs have joints. T eir bodies are divided into diff erent sections, or segments. T ey also wear tough armor. It’s called an exoskeleton. T e exoskeleton of a golden tortoise beetle


glitters like gold. In fact, it’s clear. It reflects sunlight, which causes the beetle to sparkle. T e shell can also turn red, making this beetle look like a bad-tasting ladybug. So this pretty armor helps keep the beetle safe.


No Backbone? No Problem! Jellyfish, spiders, and slugs are all invertebrates.


So are shrimps, giant clams, and grasshoppers. Make no bones about it, though. Not having a backbone is not a problem for any of them. T ese animals have plenty


of other ways to move, eat, and stay safe. With stingers, spiny skin, and shiny shells, each is built to survive.


robber crab 9


characteristic: a feature of living things that is used to help sort them into groups


classify: to organize living things into groups based on common characteristics


cold-blooded: using the sun’s warmth to control body temperature


invertebrate: an animal without a backbone


phylum: a large group of similar living things; only a kingdom is larger


Page 1  |  Page 2  |  Page 3  |  Page 4  |  Page 5  |  Page 6  |  Page 7  |  Page 8  |  Page 9  |  Page 10  |  Page 11  |  Page 12  |  Page 13  |  Page 14  |  Page 15  |  Page 16  |  Page 17  |  Page 18  |  Page 19  |  Page 20  |  Page 21  |  Page 22  |  Page 23  |  Page 24