Arthropod Investigation

Aneil Marathi PRE-AP BIOLOGY MARCH 14, 2014- GUZMAN

Lab Objectives

Students will learn about the external anatomy of arthropods. Students will focus on the structures and functions of the organism's integumentary system. Students will also understand the ecological roles of arthropods.

Background Information

The grasshopper is prevalent in many tertiary ecosystems. Part of suborder Caelifera, grasshoppers thrive in the grasslands of North America. Although seen as pests to some, grasshoppers play a key role in their habitats.

Grasshoppers have evolved and developed many different adaptations. These include specialized hind limbs for jumping, colorless wings, and a tough exoskeleton for protection.

Grasshoppers eat a variety of plants such as grasses and shrubs. They are predated on by birds, lizards, other insects, and rodents.

Grasshoppers, believe it or not, have a positive effect towards humans! They fertilize plants and eat waste. However they have been known to devastate crop fields...

Crayfish can be found in a variety of freshwater habitats. Part of superfamily Astacoidea, crayfish reside in lakes and other water features in North America. They provide food for many and have became a Southern staple.

Crayfish have adapted many different traits that have allowed them to become so ecologically successful. Some of these include strong, large claws called pincers developed to grab things and kill prey, slitted eyes, and short legs for walking on the bottom of lakes and marshes.

Crayfish prey on mollusks, worms, tadpoles, and small vegetation like algae. They are eaten by fish, turtles, herons, and storks.

Humans use crayfish both for recreation and for fine Southern dining as well as around the world.

Integumentary System- Crayfish/ External Anatomy

Crayfish have two long antennae used for sensing stimuli. They have a very hard outer covering called a cephalothorax that make up part of the crustacean's jointed exoskeleton (however the cephalothorax is not jointed). It has a pair of swimerettes under its abdomen to aid in swimming direction, accompanied by its defining feature, the two hard pincers. The integumentary system works with the skeletal system (movement and maintaining homeostasis) and the excretory system (removing waste through pores).

Integumentary System- Grasshopper/ External Anatomy

The grasshopper has two long sensory antennae that aid in determining direction and recognizing stimuli. It also has two pairs of wings that aid in air circulation. The grasshopper has a slightly softer exoskeleton than the crayfish, allowing it to move easier. Jointed legs aid in movement as wellThe integumentary system works with the nervous system (antennae sense and relay messages to the brain) and the excretory system (removing waste through pores).

Arthropod Cladogram

Big image

Interesting Facts!!

There are over 500 different types of crayfish known!

The largest crayfish ever caught was 14 lbs!!

Crayfish are part of the subphylum Crustacea.

Grasshoppers are not born with wings, and must develop them as they grow.

Some grasshoppers have a special defensive mechanism in which they spray brown liquid at enemies!!

Grasshoppers are part of the subphylum Hexapoda.