edHelper.com
Invertebrates


Arthropods


Arthropods
Reading Level
     edHelper's suggested reading level:   grades 6 to 8
     Flesch-Kincaid grade level:   7.51

Vocabulary
     challenging words:    foul-smelling, microscopic, metamorphosis, abdomen, internal, invertebrate, external, directly, segment, krill, arthropod, lead, member, waterproof, during, drying
     content words:    In Greek


Print Arthropods
edHelper.com subscriber options:
     Print Arthropods  (font options, pick words for additional puzzles, and more)

     Quickly print reading comprehension

     Print a proofreading activity


Feedback on Arthropods
     Leave your feedback on Arthropods  (use this link if you found an error in the story)



Arthropods
By Cindy Grigg
  

1     An arthropod (phylum Arthropoda) is an invertebrate animal that has an external skeleton, a segmented body, and jointed appendages. Wings, mouthparts, and legs are all appendages. The arthropod phylum is named for the jointed legs that each member of the phylum has. In Greek, arthro means "joint," and pod means "foot" or "leg."
 
2     Insects and spiders are probably the most familiar arthropods to us, but the phylum also includes animals like crabs, lobsters, centipedes, and scorpions. There are more species of arthropods on Earth than of all other animals combined. More than 875,000 species have been identified.
 
3     Arthropods have open circulatory systems. The blood leaves the blood vessels and bathes the internal organs. It is not enclosed inside blood vessels throughout the body. All arthropods have an external skeleton- an exoskeleton. Some exoskeletons are hard, like that of a crab. It is made out of chitin. Some exoskeletons are leathery, like that of a caterpillar. Both types are waterproof. The exoskeleton keeps the animal from drying out. Arthropods were the first animals to move out of water and onto land, and their exoskeletons probably enabled them to do this.

Paragraphs 4 to 9:
For the complete story with questions: click here for printable


Copyright © 2008 edHelper