Investigation 20
What is a fish?
Introduction
Points:
|290
The superclass Osteicthyes is comprised of bony fish: the ray-finned fish and the lobe-finned fish. Ray-finned
fish possess a fantastic diversity, encompassing approximately 99% of the over 30,000 described fish species.
The clade of lobed-finned fishes are ancient, encompassing only three types, one extinct, one thought to be
extinct until only recently, and one that has the ability to gulp air. Inclusively, the taxon of fish possess a
special organ that lies along the evolutionary path to living on land- the swim bladder. With modification of the
fish’s swim bladder, we end up finding lungs in our own bodies.
Objectives
1. To determine the anatomy of a Fish
2. To determine the biological diversity of the Osteicthyes grouping
3. To determine how more complex organisms live
Materials
Fish
Microscopes
Probes
Scalpels
Procedure
1. Collect a Fish. You will also need a dissecting microscope, a poking probe, and a pair of scissors.
2. Using the space below, draw a diagram of the external anatomy of the Fish, without using a microscope.
Make sure to use color and label your diagram. (100 points)
3. Begin to cut the ventral surface of the fish, from the anus toward the anterior end. You will stop relatively
short of the gills to preserve the body wall and heart. You may need to cut a “window” of flesh from the fish to
accurately see the organs.
4. Examine the interior structures of the fish. Diagram what you see with below: (100 points)
4. What type of fish were you studying? (taxonomic group) (10 points)
5. Where does this fish usually live? (10 points)
6. Describe the diversity of feeding patterns possessed by different fish. (10 points)
7. What are the predators of this fish? (10 points)
8. Explain the ecological threat posed by the Snakehead in North America. (10 points)
Study Questions
1. Is the fish a single living organism, or multiple? Explain. (10 points)
3. Describe the advantage of a swim bladder. (10 points)
4. How does the fish reproduce? Explain (10 points)
5. Describe the role of fish in aquaponics. (10 points)