What the Arthropoda?

Objective: compare two animals in the same phylum

By: Olivia Helm Guzman-4th

The Grasshopper Vs. The Crayfish

Both the grasshopper and the crayfish are members of the Arthropoda phylum. Both has some characteristics that are similar but they also have those that are specific to their individual species.

The Grasshopper

The common grasshopper can be found almost everywhere in the United States scattered all over. They are generally herbivorous feeding mostly on grass. They are preyed upon by birds, small rodents, mammals, other insects, and in some cases humans. Because they are so small and mostly defenseless, they have adaptations such as their super strong hind legs that help them to escape predators.

The Crayfish

Most crayfish are found in freshwater but some survive in salt water. They are mostly nocturnal and feed on snails, algae, worms, and tadpoles. These creatures are preyed upon by alligators, larger fish, the chicken turtle, otters, and various birds. It is also more likely to see a crayfish on the dinner table rather than a grasshopper in the United States, but not in all countries. To adapt to the murky waters that they live in, these animals have eyes on short stems that allow them to see in all directions.


The two have many traits in common due to the restated point that they're found in different phylums. For example they both have legs present. segmented abdomens, antennae present, and open circulatory systems. In this

But they're in the same phylum!

Crayfish eating grasshopper

Arthropoda Cladogram

Big image
This cladogram shows the evolutionary relationships between the crayfish and the grasshopper. On the sixth green line from the left the world Crustacea is seen. This would be the crayfish's subphylum. Then on the last green line it says Hexapoda and this is the grasshopper's subphylum. It can be seen from this that they are indeed very closely related with only three traits separating them.

Exploring the Respiratory System

Unlike the grasshopper the crayfish has the evolutionary advantage of being able to breathe underwater. This is one difference between these two creatures when it comes to the respiratory system. Instead of using gills like the crayfish, the grasshopper uses spiracles to breathe. The grasshopper has something called a tracheal system. The spiracles are tiny holes on the sides of the grasshopper that open to diffuse oxygen into the body. The air then enters the body and is moved around through a system of tracheas and air sacs. When air needs to leave the body it leaves through the back spiracles while it enters through the front. Now crayfish have a very different system since they have gills. The oxygen and carbon dioxide are exchanged between the blood and water across the gill surface as it is circulated across the branchial chamber. One cool fact about the crayfish is that its gills are attached to its walking legs so that it can breathe and walk easily at the same time.

Even though these two systems of respiration are very different they serve the same function. Without this intake of oxygen the other systems cannot operate correctly and to put it simply without this system there would be no organism. They cannot live without oxygen making this a crucial system that if damaged could be deadly

Respiratory System In Insects
crayfish breathing

Fun Facts!

Grasshopper

Some grasshoppers can jump 200 times their length in just one jump.

The smallest grasshopper is about 1.25cm.

In Japan, grasshoppers are seen as a sign of good luck.

A grasshopper's eardrum is found in its abdomen so it's almost like they hear with their stomachs

Crayfish

There are 500 species of crayfish and 350 of them can be found in the U.S.A.

Crayfish can live up to two years in captivity but much longer in the wild.

When a female lays its eggs she keeps them on her swimmerets for a very long time and usually until they hatch.