I've spent most of this past week hanging out with my threespine stickleback, trying to poke and prod them along the way to compete for limited food sources. Well, I didn't poke and prod them, but I did spend most of my Wednesday in lab conducting feeding trials. For the most part, a trial goes something like this:
1.) We select two fish from their home tank, aiming to collect a small fish and a big fish. Not only do we want a sizable difference for our data, but it makes scoring the trials easier if we can instantly tell the fish apart.
2.) We bring the fish into the lab where we run our experiments, and let them acclimate in the 3-gallon testing tanks. If we're quiet, they're good to go within 15 minutes of being moved (although maybe 1 out of every 5 trial pairs simply do not calm down and won't even eat a worm sitting on the bottom of the tank).
2b.) While the fish are "chillin' out", I take a picture above the tank for later determination of fish size and ratio.
3.) To conduct a single round, we pipet a worm into a plastic pipet, and hold the pipet in the tank until both fish are interested. To make it a fair game, both fish need to be equally interested in eating the worm. Once this happens, we let the worm fly out of the pipet and see who wins.
4.) If we have a hungry, happy pair of fish, we can get up to 25 worm rounds in a single trial.
5.) After coming up with a worm feeding score for the two fish, I turn to the computer to see how big the fish were:
standard length of each fish really easily using a ruler in Photoshop. We can then use these standard lengths to determine what the size ratio between them.
I've been studying all day today, and while I've made a lot of progress (like finishing the first draft of my poster to present at Academic Spree Day - hey! I'm on that link!!), it's time to get back to work and keep chugging. I'll be back in touch with my sad outlook of finals, which I'm actually excited to finish.