Suggested drawings.
- A side view of the entire fish, fully labeled.
- A bony rayed and a cartilaginous rayed fin.
- A scale, showing its minute structure.
- A dorsal or a lateral view of the head, showing the sense organs.
The Mouth and the Gills of the Fish
Materials.
The same materials as those used in the preceding exercise may be used here.
Directions.
The mouth, its structure and its action, can be seen by pulling the upper jaw upward and forward until the mouth and the gill chambers open fully. Examine the structure and action of the jaws, the tongue, the throat, and the teeth on each jaw and on the roof of the mouth.
Investigate the breathing apparatus from the throat side and from the exterior, noting the number, form, and structure of the gills, their attachment and their protection.
The mouth may be kept open by a short splinter or a ball of paper.
The pupil should identify the following structures:—