FOSSconnect


Crayfish—The Maine Event

Larry Malone, Co-Director of FOSS, Lawrence Hall of Science
September 03, 1998 | Observations by Larry

Late last year I got one of those letters (e-mail actually) I cherish so much. It came right to the point and took the Crayfish Activity in Structures of Life to task.

letter

I did write back and suggested that their assumption that the preference for dark they observed in house selection may not necessarily extend to feeding container selection. Recumbent crayfish may have different needs than active (feeding) crayfish. I further suggested that the way to answer their question was to conduct more investigations. I pointed out that their experimental design indicated that crayfish avoided white houses, but did not necessarily prove a broader avoidance of white objects. I suggested that they might be able to design additional investigations to get more information, and asked them to let me know if they found out anything more.

I also took the opportunity to suggest that even though it is tempting to explain crayfish behavior in terms of their emotional responses to situations, we don't have any scientific evidence that crayfish "hate" white; all we can do is observe and report what they do, not how they feel about it.

Crayfish drawing

The students continued their investigations and reported their results to me in great detail. I read every word with great enthusiasm—the series of experiments and the conclusions reached were clearly the products of motivated students guided by a masterful teacher.

To make a long story short, the students determined that crayfish were not particularly influenced by the color of the bottom of the feeding basin. They confirmed their original position that the house had to provide dark surroundings to be suitable. They were careful to report their findings in terms of what the crayfish did, not how they felt about it. Congratulations to one and all in Mr. Williams' class!

Crayfish drawing Crayfish drawing

But there is more...the students' excellent observation skills were made evident by the remarkable scientific drawings they produced after close scrutiny of the crayfish. And the students used the crayfish theme to develop some math word problems for the class to share. A few examples are included.

Any more questions? Launch 'em our way and we'll see what path of discovery and inquiry we can wander down together.

Larry Malone
lmalone@uclink4.berkeley.edu

Crayfish math

Note: Mr. Ogden Williams teaches fourth grade at Pond Cove School in Cape Elizabeth, ME.