Intro:

Hypothesis:

Make a hypothesis around your experiment relating to the feeding of the hydra.

Procedure:

1. Obtain at least three live specimens of hydra and put it in a depression slide and examine in under low power.
2. Draw a diagram of the specimen in your results section, labeling as many structures as possible.
1. Can you identify the gastrodermis and epidermis?
2. Using the needle probe, touch the hydra gently in several places. Are some areas more sensitive than others?
3. How does the animal respond to this touch?
3. Transfer your hydra to a small petri dish, and observe the animal under the dissecting microscope.
4. Introduce a drop containing these organisms to the petri dish with the hydra and watch the hydra carefully for the next few minutes. Record your observations in as much as possible.
5. Attempt to induce a hydra to release nematocysts by following the directions below:
1. Transfer a hydra to a slide containing a very small amount of water. Add a cover slip and put the slide to the side to dry somewhat.
2. Observe the hydra at intervals under the low and high power of the microscope (one discharged, you will need to use high power to observe them.
3. Diagram discharged and undischarged nematocysts that you see.