Arthropod Virtual Dissection

Gianna Haskin


The purpose of the arthropod dissection lab is to examine two preserved anthropds (grasshopper and crayfish), look for similarities in these two animals that may be phylum traits, and to look for differences in the animals that may be class traits.

Backround- Grasshopper

Phylum: Arthropoda, Class: Insecta, Order: Orthoptera. Many species of grasshoppers are general herbivores feeding on a variety of plants. Some species only like grasses. Predators include birds, lizards,mantids, spiders, and rodents eat grasshoppers. Areas with many grasses, small "vacant" lots and gardens are where grasshoppers like to live. One adaptation of the grasshopper is big hind legs for jumping.

Backround- Crayfish

Scientific name: Cambarus sp. Crayfish (with special reference to genus Cambarus) are extremely distinctive freshwater crustaceans. Their large anterior-most pairs of legs have powerful claws which are efficient tools for defense, food gathering, and object manipulation. Their four pairs of walking legs assist them in rapid locomotion across the bottom substrates of their aquatic habitats. They live in ponds, streams, rivers, and lakes most typically under submerged rocks and logs. Crayfish can survive the drying up and loss of their streams and ponds. They respond to these extreme habitat disruptions by aestivation in burrows or other refugia or by migration to still intact water sources. Crayfish consume both plant and animal materials and will, depending upon seasonal and local availabilities, consume a great variety of types of foods. Almost all aquatic plants, mollusks, insect larvae, mature insects, tadpoles, amphibian eggs, and small fish are common foods. Also taken opportunistically are small rodents and even small birds.

External Anatomy

Internal Anatomy

Step One

Examine both the Grasshopper and Crayfish.

Step Two

Determine the similarites and differences between the two animals.

Respiratory System

Aquatic arthropods (crustaceans and the chelicerate horseshoe crabs) possess gills for respiration. Although they vary in structure and location, the gills are always outgrowths of the integument (skin) and are therefore covered by the exoskeleton, which is thin in this area and not a barrier to the exchange of gases. Terrestrial arthropods possess tracheae and book lungs as respiratory organs. Tracheae are a system of tiny tubes that permit passage of gases into the interior of the body.

Additional Information- Grasshopper

  • A grasshopper has Antennae not very long, 20-24 segments and Conspicuous eyes. They are widespread in U.S. As herbivores, grasshoppers link plants to the rest of the ecosystem. Frass (droppings) contribute to nutrient turnover by returning nutrients as fertilizer for the plants. They provide food for birds and other arthropods.
  • Aditional Information- Crayfish

    Species of crayfish are widely distributed throughout the world and are found abundantly in most of the continental United States. Crayfish are very intolerant of pollution and other human-generated fouling of their environment. A rich crayfish population, then, is a very positive index of habitat quality. Crayfish are an important component of our stream ecosystem. They are significant links in the complex aquatic and terrestrial food webs in our ecosystem and, by their feeding, burrowing, and foraging activities, help to maintain a high level of water quality in our stream to the great benefit of so many of our Nature Trail species.


    "Crayfish." Crayfish. N.p., n.d. Web. 03 Apr. 2014.

    "Grasshopper Information." Grasshopper Information. N.p., n.d. Web. 03 Apr. 2014.

    Barnes, Robert D. "Respiratory System." Encyclopedia Britannica Online. Encyclopedia Britannica, n.d. Web. 03 Apr. 2014.