Slide of preserved budding hydra
Living specimens of hydra
Daphnia or fish food
1. The Hydra belongs to the Kingdom _________________________
and the Phylum __________________________________________
2. What are cnidocytes?
3. Where do hydra live?
4. Name two other organisms that are closely related to the hydra.
5. Obtain a slide of a living hydra and observe under scanning and low power. Note that you do not have a cover slip on the slide so you should NOT use the high power objective. The hydra is visible on the slide without the microscope.
Describe the hydra. What does it look like? How does it move?
6. Because the hydra moves around on the slide, it can be difficult to get a good view of it. Your teacher may provide you with a "Preserved Hydra" slide which contains a hydra that has been fixed to the slide. This hydra is no longer living. Sketch your preserved slide below (or living hydra) and label it.
Hydra at low power (100x)
*Label the: Basal disk | Tentacles | Gastrovascular cavity (area) | Cnidocytes | Mouth | Bud (if present)
7. Count the number of tentacles on your hydra. How many does it have? ____________
Compare this number to other hydras. Are all hydras the same? _______
8. Hydra Behavior - Use a dissecting pin to gently touch your hydra. Describe its reaction.
*You may also try adding fish flakes or live Daphnia to your slide to see if you can observe the hydra eating.