Expert experiments

We're experimenting with some indirect (i.e. smo as middlewoman) scientist-student interaction via email. Mike Denniston’s students took photos of the small crayfish that they found in the Kennebunk River. It’s now in their classroom, and they’re growing it to see if they can ultimately identify it when it matures.

I emailed the Kennebunk students' photos to crayfish experts Karen Wilson, Matt Scott, and Will Reid. Karen was the first to reply (see her great email below). I’ve forwarded her email along to Mike and his students, and have asked Mike to give us some feedback on his students’ (and his own) reaction to a scientist’s keen interest in their data collection. Awaiting the delicious results of this expert experiment!

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From: Karen Wilson [mailto:kwilson@usm.maine.edu]
Sent: Thursday, November 06, 2008 10:45 AM
To: Matthew Scott; Sarah Kirn; Sarah Morrisseau; wmreid1@verizon.net
Subject: Kennebunk crayfish (Or, what to do while your crayfish grows)

Hi Sarah and all!

The message I'd send to the students is that it looks like, at first glimpse, that they have a crayfish that is probably native (not a rusty crayfish in any case), and, as they've figured out, a male. I've attached a photo of the pleopods on much larger crayfish that I took to give them a feel for the angle we'd need in order to identify the crayfish to species. They should most definitely let him grow up a bit more, then take some more photos! As he grows there are few things the students can look at: Watch the crayfish feed - how does he use each type of claw, leg or maxiliped? in what order? Does he use his antennae? If the aquarium has gravel the students might notice the crayfish probing the gravel with some of his walking legs - they've got sensors on them that can help the crayfish find food that is buried. The students could try some simple feeding experiments: does he find food faster is the aquarium water is circulating than if its not (watch for antennae activity)? What if the food is buried in the gravel a bit? If the students have done any water quality sampling, they could monitor water quality in the crayfish tank - you'll notice that conductivity goes up after a water change - because the crayfish is excreting nitrogen produces, among other things. Really high conductivity means its time to change the water! This may be measurable on a smaller time scale if you put the crayfish in an aerated jar of relatively new water (but not distilled water!) and measure conductivity over the course of the day. As for molting - is the crayfish being fed a bit of tetramin or other fish food flakes each day?

Some day I'd love to visit the Kennebunk school and talk about crayfish with the kids - that'd be fun.

Karen