Counting Big Fish
In the app below, you will count ALL of the fish in the tank -- top, middle, and bottom layers. Once you have the total count, you need to divide by the volume of the tank to find the density of fish.
NOTE: we are assuming that you have a sort of "snapshot" of the tank, so we don't need to worry about fish moving around. When you see fish on different layers, they really are different fish, not the same fish that changed places.
In any case, the fish at Cap. Flint's Spectacular were pretty bored, and they really didn't move around all that fast...
Counting Parrotfish in a gunky tank
Follow the steps on the right to calculate the density of fish in this gunky fish tank.
Click on each layer to count.
Pretty easy, right? This is basically the same thing you will be doing when you use a hemocytometer. But... there are a few more twists just to keep things interesting.
photo credits: parrotfish
Copyright University of Maryland, 2007
You may link to this site for educational purposes.
Please do not copy without permission
requests/questions/feedback email: mathbench@umd.edu