Exoskeleton Found

By: Susan Yu Mitcham-PAP Bio-6

Objectives - Arthropod Dissection

In this lab the students will observe two preserved arthropods, a grasshopper and a crayfish, to help students better understand Arthropods. Students are to pay attention to the similarity and differences of the two animals, since this will help students better understand the characteristics of arthropods.

Hop into Life of a Grasshopper

Grasshoppers or also known as Caelifera are herbivores. They eat grass, leaves, stems, flowers, seeds, and sometimes dead insects. They are preyed by skunks, blister beetles, ground beetles, shrews, moles, salamanders, toads, and snakes. Grasshoppers are found in temperate, tropical, and terrestrial habitats. Many live in deserts or dunes, chaparral, forest, rain forest, scrub forest, and marshes. In their ecosystem, grasshoppers are considered important herbivores. They are the base of many food webs in every ecosystem. Due to the amount of predators the grasshopper has strong hind legs that allow them to leap up to 20 times its length to escape predators. To add better protection the grasshopper usually have mad camouflaging skills. And the most important adaptation that this lab is about the exoskeleton that protects the insides of the grasshopper.


Nature ( The Grasshopper )

Crazy for Crayfish History

Crayfish's scientific name is Astacoidea. These animals are found in temperate and freshwater habitats located in lakes, ponds, rivers and streams. Crayfish mostly feeds on insects, snails, other invertebrates, aquatic plants, and algae. Predators of the crayfish are fish, otter, raccoon, mink, and great blue heron. In their ecosystem, crayfish serves as an important food source for their predators and act to control the populations of their prey species. These crayfish have well-adapted eyes that see all directions for predators, big pincer to fight off any enemies or grab food, two pairs of antennae that help detect movement in water, and an EXOSKELETON to protect the body.


A minute for Nature by Paul Relaplaces nature video crayfish in a stream

Integumentary System

Arthropod's integumentary system is the exoskeleton. Exoskeleton contains rigid and resistant components that fulfill a set of functional roles such as protection, excretion, sensing, support, and feeding. It is made up of chitin and the addition of calcium carbonate makes them harder. When these skins are outgrown, it is shed in a process call molting. The epicuticle is the outermost part of the cuticle. Its function is to reduce water loss and block the invasion of foreign matter. The innermost layer of spicuticle is often called the cuticulum layer, a stratum composed of lipoproteins and chains of fatty acids embedded in a protein-polyphenol complex. An oriented monolayer of wax molecules lies just the cuticulim layer; it serves as the chief barrier to movement of water into or out of the insects's body. In many insects a cement layer covers the wax and protects it from abrasion.

Grasshopper Dissection

Grasshopper Anatomy Part 1




Posterior section of body containing reproductive and digestive organs

Compound eyes

Most prominent anterodorsal feature of the head; For vision

Simple eyes (ocelli)

Situated atop the cranium and between the compound eyes; 3 small circles; For detecting light


Short and thread-like; detect touch, movement, and odors; olfaction and proprioceptions are functions

Mouth parts

Adapted for chewing; consists of the mandibles;upper jaw, maxillae;lower jaw, labrum;upper lip, labium;lower lip, and hypopharynx;tongue equivalent


Highly mobile appendages for handling food; attached to the maxilla and labium


Locomotory organ attached to thorax and abdomen


First segment of the leg adapted for walking


Middle segment of the leg adapted for walking


Last segment of the leg modified for jumping


Largest, thickest part of the metathoracic segment of the leg; helps with hopping


Long, spine-encrusted part of the metathoracic segment of the leg


Outgrowths of the body wall that enable the insect to fly


A saddle-shaped shield on the prothorax; used for protection

Grasshopper Fun Facts

  • have ears on their belly
  • make music by rubbing hind leg against fore wing
  • causes billions of dollars in damage to food crops, annually, worldwide
  • provide important source of protein to people in many parts of the world
  • exists long before dinosaurs
  • can leap up to 200 times their length in one jump
  • temperature can be determined based on their chirping
  • young grasshoppers can eat two times their weight in a day


Crayfish Organs!


the two divided parts of the crayfish's body


the part of the exoskeleton that covers the cephalothorax


organs of touch, taste, and BALANCE


organs of touch, taste, and SMELL


the jaws


hold solid food, tear it, and pass it to the mouth.


the first three appendages on the cephalothorax, hold food for eating


the large claws that the crayfish uses for defense and to capture pray

walking legs

help for navigation


create water currents and function in reproduction


the sixth segment of the abdomen


bears the anus

cervical groove

separates the head and the thoracic regions


help for breathing.

Crayfish Dissection

Crayfish Dissection

Crayfish Taxonomy

Kingdom: Animalia

Phylum: Anthropoda

Subphylum: Crustacea

Class: Malacostraca

Order: Decapoda

Suborder: Pleocyemata

Infraorder: Astacidea

Superfamily: Astacoidea

Grasshopper Taxonomy

Kingdom: Animalia

Phylum: Anthropoda

Subphylum: Hexapoda

Class: Insecta

Order: Orthroptera

Suborder: Caelifera


Tiny Crayfish Discovered

A new species of crayfish discovered in southeast Australia's coastal lakes and swamps is one of the world's smallest crayfish species, researchers report.

The tiny, blue-black crustacean resembles its larger cousins that end up in cooking pots, such as lobsters and crawdads. But this species, which locals call a lake yabby, measures only 0.5 to 0.7 inches (12 to 18 millimeters) long. The biggest one found was just 0.8 inches (21 mm) long, and weighed 0.2 ounces (7 grams). Read more: http://www.nbcnews.com/science/environment/adorably-tiny-crayfish-discovered-its-cannibal-n77081

Crayfish Fun Facts

  • is a freshwater variant of a lobster
  • when they molt, they eat their old exoskeleton
  • comes in variety of colors such as blue, white, red, pink, sandy, yellow, and dark brown
  • with proper care, crayfish can live two years in captivity
  • over 350 species of 500 in the world lives in United States
  • live in every continent except Africa and Antarctica

Work Cited

"Grasshopper Information." Grasshopper Information. N.p., n.d. Web. 09 Apr. 2014.

"Crayfish Dissection." YouTube. YouTube, 07 Mar. 2013. Web. 10 Apr. 2014.

"Friends of Rietvlei." Friends of Rietvlei. N.p., n.d. Web. 10 Apr. 2014.

"A Minute for Nature by Paul Relaplaces Nature Video Crayfish in a Stream." YouTube. YouTube, 10 Aug. 2012. Web. 10 Apr. 2014.

"Grasshopper Anatomy Part 1." YouTube. YouTube, 05 Feb. 2012. Web. 10 Apr. 2014.

"Crayfish." Wikipedia. Wikimedia Foundation, 04 Sept. 2014. Web. 10 Apr. 2014.

"Adorably Tiny Crayfish Discovered (and It's a Cannibal)." NBC News. N.p., n.d. Web. 10 Apr. 2014.

"Nature ( The Grasshopper )." YouTube. YouTube, 28 Aug. 2010. Web. 10 Apr. 2014.