Arthropod Lab

John Labador




-Look for similarities between 2 arthropods

-Look for differences between 2 arthropods

Background Information (Grasshoppers)

Grasshoppers have antennae that are generally shorter than their body and short ovipositors. They also have pinchers or mandibles that cut and tear off food.[1] Those species that make easily heard noises usually do so by rubbing the hind femurs against the forewings or abdomen (stridulation), or by snapping the wings in flight. Tympana, if present, are on the sides of the first abdominal segment. The hind femora are typically long and strong, fitted for leaping. Generally they are winged, but hind wings are membranous while front wings (tegmina) are coriaceous and not fit for flight. Females are normally larger than males, with short ovipositors. Males have a single unpaired plate at the end of the abdomen. Females have two pairs of valves (triangles) at the end of the abdomen used to dig in sand during egg laying.

Background Information (Crayfish)

Crayfish – also called crawfish, crawdads, freshwater lobsters, or mudbugs – are freshwater crustaceans resembling small lobsters, to which they are related; taxonomically, they are members of the superfamilies Astacoidea and Parastacoidea. They breathe through feather-like gills and are found in bodies of water that do not freeze to the bottom. They are mostly found in brooks and streams where there is fresh water running, and which have shelter against predators. Most crayfish cannot tolerate polluted water, although some species such as the invasive Procambarus clarkii are hardier. Crayfish feed on living and dead animals and plants

Respiratory System (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.

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 breath.

A crayfish has a pocket where water is stored. The water is stored so the crayfish can walk on land and still breath. A crayfish has to have water in order to breath.

As the crayfish walks, the surface area of the gills spread so the water can pass through in order for the crayfish to breath.

Other Information

Grasshoppers belong to the class Insecta whereas crayfish belong to th class Crustacea