The Transparent Water Flea/The Hydra: Up Close and Personal/Jellyfish Get A Bad Rap
Name _______________________________________________________ Pd __________ Date __________
Directions: Read the articles about the Daphnia and Hydra, and answer the questions that go along with them.
Page 193, Page 199-201, and Page 202-203
1. What kingdom does the Daphnia belong to?
Animal Kingdom
2. Name and describe the phylum Daphnia belongs to.
Arthropods – joint limbed organisms
3. Please list four characteristics of crustaceans.
External Skeleton
Gills for gas exchange
Two pairs of antennae
Numerous jointed appendages
4. Why are Daphnia called transparent water fleas?
Their exoskeletons are transparent, they live in water, and their jerky motion resembles the way
a flea jumps
5. How do Daphnia “jump” in the water?
They “jump” by quickly flipping their antennae downward
6. Where do Daphnia live?
Almost any freshwater environment: lakes, ponds, streams, swamps, and marshes
7. What do Daphnia eat?
Microscopic organisms such as: bacteria, algae, and protozoa
8. Why are Daphnia important?
They provide an important link in the food chain between the microscopic organisms they prey
upon and the larger organisms that prey upon them.
9. What kingdom is Hydra a part of?
Animal Kingdom
10. What phylum is Hydra a part of?
Cnidaria
11. List and describe the Hydra’s most common form of reproduction.
Budding – a small growth (bud) forms on the adult hydra’s body through a series of cell
divisions, the bud develops tentacles and breaks away to live independently.
12. List all three ways a Hydra is known to reproduce. Which of these is the same as the blackworm?
Budding
Regeneration (same as the blackworm)
Sexual Reproduction
13. Through what process does the Hydra get nutrients and oxygen, and get rid of carbon dioxide and
other wastes?
Diffusion (Remember that famous story that took place in Diffusion, Arizona?)
14. What are nematocysts? Describe what they do for the Hydra.
Nematocysts are specialized stinging cells
Nematocysts help the hydra by paralyzing and capturing their prey
15. How does the Hydra move about? (Two ways)
It floats from one place to another or does somersaults
16. List two ways that Hydra and jellyfish are similar and two ways that they are different.
Similar: 1. Aquatic 2. Have stinging cells
Different: 1. Jellyfish are much larger than hydra 2. Jellyfish can contract and relax their body
to propel themselves through the water, and hydra can not.
17. List and describe two ways that humans can affect the jellyfish population.
1. When humans allow fertilizer or waste products to get into the water this decreases the
oxygen levels and increases the jellyfish population
2. Overfishing from humans has left jellyfish with very few predators, which causes jellyfish
numbers to increase.