Virtual Dissection Lab
This presentation demonstrates the internal and external structures of an earthworm. The organs of the worm will be stated and a specific system of the earthworm is described thoroughly. The ecological role of an earthworm will also be included. Dissecting an earthworm allows one to view and understand the bodily functions of the worm.
Predators: Snakes, birds, rodents, some insects
Prey: N/A (They eat the nutriets and the soil, they are decomposers)
Ecological Adaptations: -Mucus coating helps oxygen pass through the skin when in air or water
-Streamlined body shape allows it to move through the soil.
Earthworms are the largest members of the class Oligochaeta. They are organisms that are not only used for fish bait, but also help the environment by physically improving the structure of soil and by improving the soil's aeration, porosity, and permeability. Their segmented body allows them to navigate through the soil efficiently. Their digestive system includes many parts that add their own unique function to the system. The diagram to the left is an example of an earthworm cladogram.
Mouth- first part of the digestive system that takes in food
Pharynx- pumps food and soil into the esophaus
Esophagus- food that leads food to the crop
Crop- stores food
Intestine- transports nutrients and soil through the digestive system
The Fascinating Movement of an Earthworm
Habitat: Small ponds, lakes, streams, rivers
Predators: Larger fish, birds, herons, gulls, eagles, hawks, kingfishers, mergansers, turtles, bullfrogs
Prey: live insects, crustaceans, small fish, and various other small creatures
Ecological Adaptations: -large eyes to aid in feeding and giving the perch good vision
-spines for protection
-stiffness in fins, and a thin shortened disc-shaped body, making it harder for predators to swallow
-stripes for camouflage protection
The perch, of which there are three species in different geographical areas, are freshwater fish. The diagram to the left is an example of a perch cladogram.
The circulatory system of a Yellow Perch is a low pressure, single loop system which means that there is one direction of blood flow from the heart that acts as a pump. Deoxygenated blood is pumped throughout the heart and goes to the gills which is where the blood becomes oxygenated. The blood then goes straight to the body. The organs that make up the circulatory system of a perch are the:
Heart- muscular organ helping blood to circulate
Atrium- upper chambers of the heart that receive the blood and turns it into the ventricles
Ventral Aorta- circulates the blood from the heart to the gills then on through the head and the body
Gills- organ that extracts oxygen from the water
Dorsal Aorta- carries blood from the heart to the organs
Jugular Vein- carries blood from head to face
Kidney- maintains the pressure of internal fluids
Ovary Reproductive System- an egg-producing organ
Stomach/Intestine- breaks down food by enzymes and makes it into a liquid mixture which empties into the small intestine.
Liver- all the blood goes through it and it is always processing food.
Fun Facts and Awesome Perch Dissection Video!
- The three types of perch: Yellow, European, and Balkhash perch
- Perch are destroying the ecosystem of the Nile River by consuming many other species and overpopulating the river.
- Perch are in the secondary consumer trophic level
- Perch are found in Britain, Europe, South Africa, Asia, and Australia.
Habitat: dry open areas with lots of grass and other low plants
Predators: Birds, Lizards, Mantids, Spiders, Rodents
Prey: grasses, leaves, cereal crops
Ecological Adaptations: -specialized third limbs to jump up to one meter to avoid predation
Habitat: Marine Environments
Predators: fish, birds, alligators, humans, turtles
Prey: Dead insects, worms, algae types, dead fish, live small fish
Ecological Adaptations: -females store sperm until they're ready to lay eggs
-four legs for walking on land
Facts Facts Facts!
- The arthropod group has provided numerous numerous benefits to humans, although humans have shown an opposite effect. Us humans farm various arthropods for food (crabs, lobsters, shrimp.) We also compete with them for food, since they eat the crops that we grow for agriculture. However, some arthropods do gain from humans because they use us as their hosts (mosquitos, chiggers, fleas.)
- Arthropods have been on Earth for 428 million years.
- Arthropods are in the trophic level primary consumers.
Brief Crayfish Dissection