Arthropod Lab by Melody Peng Pre-AP Biology Guzman P.6

Phylum Arthropoda

Phylum Arthropoda is one of the largest animal phylum. It belongs to the kingdom Anamalia. With its diversity, arthropods can live in both land or water. With almost a million species discovered, the Arthropods make up the largest phylum in the Animal Kingdom. Four out of five animal species on earth are actually arthropods. 90% of these arthropods are insects, with 10% percent of this diverse group ranging from crabs, spiders, scorpions, and many other arthropods.


You will be focusing on the arthropods, grasshopper and crayfish. You will also learn the crayfish, and the life of a grasshopper. You will learn more specifically about the circulatory system of the crayfish.

The Crayfish Circulatory System

The circulatory system works to transport blood, provide the body organs with food and help get rid of harmful by products.The circulatory system of the crayfish has no veins. It is an open circulatory system, where blood is only partially contained within a system of blood vessels.Two arteries leave the heart, the abdominal aorta (toward the posterior) and the anterior dorsal aorta (toward the anterior). Blood flows from the dorsal arteries to capillaries and then into tissue spaces called sinuses which function as veins.

Fun facts about Arthropods

  • they all have bilateral symmetry
  • they have exoskeletons
  • Ancestral arthropods were the first land animals
  • they molt their exoskeleton
  • they cover more than half of the world's animal species