I Started The 11-KT Experiment

I just finished dosing aquariums in my lab with different levels of 11-Ketotestosterone to observe what, if any, effect it will have on young scarlet shiners over the next 6-12 months. I have six 10-gallon tanks, each with a hanging filter but no filter pad so as not to trap 11-KT, and 3-5 young fish in each tank. Two of the tanks have received 35 nanograms of 11-KT, two tanks received 15 nanograms, and two tanks received nothing as controls (except 2 ml of ethanol, since the 11-KT is supplied suspended in ethanol). The effects we're looking for will be differential growth in the brain, either the overall size of the brain or the growth of individual structures such as the optic tectum and telencephalon. Paul just finished his project on 14 wild-caught young scarlet shiner brains by taking digital images of the brains, and making measurements on the brains for overall size and the size of individual brain regions. That will probably inform how we analyze our results.

I finally curated some recent stream collections from the stippled studfish project. This involves ID'ing all of the fishes we kept, and as usual I notice things in the lab that weren't apparent in the field. For instance, we found a burrhead shiner at Channahatchee Creek in Elmore County, which isn't really surprising but I just wasn't looking for it as we were seining fish. We also found a silverstripe shiner there, so there are my old friends from an earlier project. Most of what we've kept from these Tallapoosa system creeks are pretty shiners, Lythrurus bellus. Those shiners could be an interesting project just because they're so common around the Tallapoosa, and I haven't found much information on them. I already have a pretty good collection of them!