Vu-PAP Bio- 4 Melissa Barbosa


They are in the phylum Anthropoda, and they are a small group called classes. An anthropod is an animal with a segmented body, exoskeleton, jointed appendages, and examples are insects, spiders and scorpions.


a) examine two preserved anthropods- a grasshopper and a crayfish

b) Look for similiarities in these two animals that may be phylum traits

c) Look for different differences in these two animals that may be class traits, Grasshoppers belong to the class insects whereas crayfish belong to the crust crustacea.

External view of Crayfish (labled)

Respiratory System (crayfish)

The Crayfish a very unique way of breathing. The gills of the crayfish are located on the outside of the body between the crayfish body wall and carapace. If you were to detach one of the crayfishes walking legs, you would observe that the crayfish's gill is attached to its walking leg. The crayfish's gills are attached to the walking legs, so as it walks, it can breathe. A crayfish has a pocket where water is stored. The water is stored so the crayfish can walk on land and still breathe. A crayfish has to have water in order to breathe. As the crayfish walks, the surface area of the gills spread so the water can pass through in order for the crayfish to breathe.

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External Labled View of Grasshopper


The exchange of gases in a grasshopper happen through the tracheal system but begins at the spiracles where air is taken in first. This system contains of ten spiracles located in the abdominal area and the others are thoracic. Oxygen diffuses into cells directly into the atmosphere and that completes the grasshoppers process of respiration. The air sacs that the tracheal system works to create can be compared to human alveoli because it stores carbon dioxide and oxygen when the respiration is taking place. However, we take air in from our mouths and nose while their spiracles do that with the control of their brains. A few of the spiracles are involved in the expiration of air as well. The human tracheae performs the role of cleaning air while the grasshoppers tracheal system works as an independent function not involving the circulatory system.