Objective: The students will set up controlled crawfish (Crustacean) experiments in order to organize, analyze, and draw conclusions from the collection of raw data.
Materials Needed:
2 or 3 Liter Soda Bottle ( One per student)
Substrate for bottom ( Sand, clay, soil, etc.)
Non-chlorinated water (Aged water)
1 crawfish of same sizes and weights
Triple beam scale
Rulers
pH meter (Attachment for TI-82 or Casio)
Light probe(Attachment for TI-82 or Casio)
Graphing calculator
Data collection sheet
Graph paper
Aquatic plants such as alligator weed
Scissors
Gloves
Food source (Independent variable) Examples
may include dog food, weiners, crackers, fish food, broccoli.
Procedure:
1. Cut off the top of
each bottle about 2 inches from the top using a pair of scissors.
2. Weigh the substrate
so that each bottle contains the same amount.
3. Place 2 aquatic plants
in each bottle. Be sure to bury the roots.
4. Fill each bottle
with the same amount of aged water.
5. Place a crawfish
of comparable size in each bottle.
6. Record all your experimental
set-up data on data collection sheets.
7. Formulate a testable
hypothesis.
8. Begin to feed the
crawfish the chosen food.
9. Measure and record
the growth rates on a day by day basis.
10. Collect data at least ten days and
return crawfish to its natural environment.
11. Calculate the average growth rates
of each crawfish and then find a class average.
12. Graph the results and present them
to the class.
13. Attached is a powerpoint to provide
more details. PowerPoint
Teacher: Gilbert Hartzog,
Jr.
Franklinton High School
email: ghartzogffa@yahoo.com