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Animal Themes
Invertebrates
Oceans


Crabs


Crabs
Reading Level
     edHelper's suggested reading level:   grades 3 to 6
     Flesch-Kincaid grade level:   6.79

Vocabulary
     challenging words:    fierce, boxing, capitol, crayfish, distinctive, hence, modify, pincers, species, triangular, vegetation, predator, material, actually, perfectly, stalks
     content words:    United States, Washington Monument


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Crabs   

1     Crabs are fierce warriors! To demonstrate their forcefulness, they put their weapons -- a pair of claws -- close to their heads, in plain view to warn potential enemies. To protect their bodies, they have outer shells (carapaces) made of a hard material called chitin. To be able to spot danger quickly, they elevate the position of their compound eyes and place them on stalks. Though these features make crabs excellent soldiers, it is their style of walking that brands crabs distinctive fighters. You see, while most warriors confront their enemies by stepping forward, crabs do so by moving sideways!
 
2     Crabs have ten legs, but they only use eight for locomotion. Can you guess which two are not designed for assisting crabs to move around? Yes, it is their first pair! Crabs modify their two front legs and transform them into claws (or pincers, chelae). These claws have dual functions. The first is to fend off predators, and the second is to gather food. Crabs are mostly scavengers, feeding on dead animals or organic debris. As they travel across a sandy beach or the seabed, they rely on their two feelers -- located near their eyes -- to detect food. Once they find it, they use their claws to pick it up and deliver it to their mouths.
 
3     Like lobsters, shrimps, and crayfish, crabs are crustaceans. Yet, unlike their close relatives, crabs do not have apparent, tail-like abdomens. They opt to fold their short, flat abdomens (nicknamed "aprons") underneath their broad carapaces. Though both sexes of crabs look alike, the shape of their aprons is often a giveaway. Let's use the blue crab as an example. Blue crabs live along the coast of the eastern United States. Their meat is delicious and a prized item on the dinner menu. But how can we tell if a blue crab is a "he" or a "she"? Well, all we need to do is flip it upside down and look at its apron. A male blue crab (or a "jimmy") has a long, narrow, inverted Y-shaped apron that looks like a Washington Monument. An immature female blue crab (or a "sally", "she-crab") has a triangular apron that reminds us of a pyramid. A mature female blue crab (or a "sook") has a semicircular apron that is reminiscent of the dome of the U.S. Capitol.

Paragraphs 4 to 7:
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