The Life of an Arthropod

Virtual Dissection Lab

Arthropoda

Arthropods aka arthropoda are a phylum of organisms with an exoskeleton and a divided body. They also have jointed appendages and legs, along with bilateral symmetry. In class, we studied grasshoppers and crayfish whom are just two examples of the vast phylum. Grasshoppers belong in the class insecta and Crayfish belong in the class crustacea. They both have the classic features of all arthropods, but are each slightly different from one another. Crayfish are mostly aquatic, whereas grasshoppers are all terrestrial. Crayfish possess two pairs of antennae and grasshoppers just one. One important difference is that crayfish breathe through gills while grasshoppers use their lungs.

Objectives!

Students will be learning about the external and internal anatomy of the crayfish and grasshoppers. Students will examine the differences and similarities between the two. By dissecting the two, the students will learn more about the organs specific to the respiratory system and their functions. Students will also learn about how an arthropod contributes to its ecosystem.

Background Info!

Arthropod Dissection

Respiratory System

Arthropod's respiratory system serve to exchange the gases through use of gills and lungs. The oxygen is taken into the organism's bodies and is later released in the form of carbon dioxide. The grasshopper and the crayfish have very different respiratory systems even though they are both arthropods. The grasshopper uses lungs to breathe, but the crayfish use gills to breathe underwater and air sacs when on land. The respiratory system is composed of: book gills, lungs, tracheae, spiracles, and air sacs. The respiratory system interacts with the cardiovascular and the circulatory system. They all work together to get the oxygen taken from the air spread throughout the body (using the bloodstream) and eventually taken to the heart. This allows the heart to oxygenate blood and, later, release carbon dioxide.

Symbiotic Relationships

An article about arthropods's symbiotic relationships with vectors for diseases is down below. Enjoy!

TRophic level

Arthropods belong to the 2nd and 3rd trophic levels because they eat both plants and other organisms that eat plants.

Population dynamics

The population of most arthropods fluctuates along with the seasons. For example, in the summer and spring, more grasshoppers are likely to inhibit an area due to the increase in vegetation. Wet seasons are better for crayfish because there will be more water for them to live in without the concern of overpopulation in a small pond. Read the article down below to find out more about how the population of arthropods is affected by their dispersal abilities and generation time.

Humans Impacts on Arthropods

This article highlights the way human settlements have affected arthropods.

evolution

environmental responses

If you'd like to know more about how arthropods are affected by environmental changes, I suggest that you purchase this book down below. It's a great read, and it discusses how drastic environmental change can lead to the disruption of cellular responses in arthropods.

Facts about arthropods you Probably did Not Know!

  • Grasshoppers have special types of grass they prefer
  • crayfish can live up to 2 years in captivity
  • some grasshoppers spit a brown substance as a defense mechanism
  • a hydrogeologist is one who studies crayfish
  • prior to molting, grasshoppers become nearly inactive and don't eat
  • there is a cray fish called the "dwarf crayfish" it is EXTREMELY small

Map of cRAYFish Locations

My Experience

Dissecting an arthropod was both fun and a great learning experience.

Even though we didn't hands-on dissect the arthropods, looking at the pictures allowed me to clearly see the external and internal anatomy and differentiate between grasshoppers and crayfish. It was very exciting and I learned much about arthropods's organs and their functions.

Below are some pictures from the diagrams we studied in class:

Feel like you know more now? RElax and read this funny story about crayfish!