1. Lesson 5: Living Where Land and Water Meet: Fiddler Crabs
Question: What will the crab need in its habitat to survive?
Hypothesis: Use the Animal Background sheet to predict what the crab needs.
Fiddler Crab Habitat Proposal
Draw and describe your ideas for the fiddler crab’s classroom home. 1

2. ANALYZE: What are the elements of the fiddler crab’s habitat?
Natural Habitat
Classroom Habitat
Salt water
Dechlorinated tap water with Instant Ocean
Space to live in
A tank
Plants
Model of hair grass (marsh grass)
Food
Fish flakes, apples, lettce, and bananas
Sand and mud
Sand humus mixture
Light
Natural light
Air
Classroom air and tank water
TG 24

3. habitat and illustrate.
Build the fiddler crab
habitat and illustrate.

6. Schedule Feeding Feed once a day. Put food in water and on land.
Remove old food before adding fresh food.
Can also feed small pieces of apple, banana, or lettuce on the sand.
Water
Change the water once a week.
Slowly lift the water bowl, dump the water, rinse the bowl, replace the bowl in the habitat, and refill water.
Important not to spill water onto the sand.
Move habitat gently.

7. Feeding Observations Put plankton in water and on land.
What happened when you put food in tank?
Do the crabs respond to the food the same way the frogs do?
How are the crab’s responses different?

8. Classroom air and through skin in water
HABITAT INFO CHART
Frogs
Crabs
Millipedes
Humans
FOOD
Fish flakes
Bloodworms
Plankton
WATER
Fresh Water
Salt water
Shelter
Plants/rocks
Tunnels under Shells
Space
Tank/pond
Tank/ Beach
Air
Classroom air and through skin in water
From water and classroom air

9. Animal Studies Log Checklist
Frog
Crab
Millipede
Daily Behavior
What does the animal do during the school day?
What do you think the animals does at night?
What does the animal eat? When? Why?

10. Fiddler Crab Observations Chart Observations should be made daily.
Date
Time
Observed Behavior

11. Reading Selection Read the selection and answer the following:
1. Write 2 or 3 things you discovered about how people study dolphins.
2. How is the animal research you are doing similar to the dolphin research being done at the research center? How is it different?
3. How is your animal log similar to the data sheet the research center is using? How is it different?

14. Extensions Research other kinds of crabs and create a display.
Use a Venn diagram to compare the classroom habitat of the crab with its natural habitat.
Feed the crabs a variety of foods to discover which the crabs prefer. Experiment with tuna flakes, shrimp pieces, green vegetables, and fruits.
Crustaceans are a popular food source for humans. Research the nutritional value of crustaceans, as well as diverse ethnics dishes that use these animals.

15. Lesson 6: Observing the Fiddler Crab More Closely
Question: What characteristics of the crab help it to survive in its natural habitat?
Hypothesis:
Plan: Observe the features of the frog in a tank and in a cup using a hand lens. 15

16. Observation: Observation Chart
Characteristic
Observations in Tank
Observations in Cup
Body Covering
Body Structures
Movement
Color
Shape
Size

17. Draw an illustration of the
fiddler crab.

18. (sef-uh-loh-thawr-aks)
TG p. 51
kee-luh

19. (sef-uh-loh-thawr-aks)
kee-lee
kre-puhs-kyuh-ler

20. Fiddler Crabs Indigenous to U.S. costal areas Brackish marshes
Body Structure
Head/thorax and small abdomen
Eyestalks
2 pairs of antennae—smell and touch
Claws
Semiterrestrial
Life span of approximately 2 years

21. Take Home Activity Lesson 6 Blackline Master