A Pleasant Jaunt To Limestone Creek On Friday

We were lucky to be able to take advantage of the beautiful early spring weather on Friday afternoon and go to Limestone Creek at the Mooresville Road site in Limestone County. It was sunny, about 60 deg. F, with light winds. We were interested in collecting about 20 scarlet shiners primarily for gut content examination. The creek was a little high, as usual this time of year, and around the riffles area which is an old ford the current was probably running about 20 knots in knee-deep water. We found the scarlets we wanted, but they were all in one small area that was protected by a low bar from the fastest current. Scarlets like flowing water but not white-water level like much of the creek that day. It was the best physical workout I had all week, wading upstream against a current that strong. We also found lots of black darters, with the males coloring up and many females plump with eggs. A large female rainbow darter was almost deformed she was so gravid with eggs (we let her go, along with all of the other darters). So spring is starting in north 'bama. James, Brittany and Alexandra were all able to go out with me. We've begun a fairly ambitious gut content monitoring project with scarlet shiners in Limestone Creek, and telescope shiners in Estill Fork. This also includes collecting length/weight data, and probably looking at some more brains too.

Kris has some interesting data on our mummichog DNA project. We're finding that there's a little more diversity in the mitochondrial cyt-b gene in northern populations (Cape Cod and Nantucket) than there is in southern populations (Charleston, SC, and Sapelo Island, GA). This is contrary to what's usually found for reasons having to do with the northern populations are recent, only about 12,000 years old, since that's when the glaciers finally melted in New England. And DNA sequences from Chincoteague and Virginia Beach, VA, are markedly different but intermediate to the northern and southern populations. We're still coming up with a final phylogentetic tree. The Neighbor-Joining algorithm using 1000 bootstrap resamplings shows the best, once we clean it up I hope to post it here. And Kris just called and told me that he's found a complete cyt-b sequence in a recent paper that's from a Maine fish, so we have one more northern sequence to plug into our tree. I'd expect it to be pretty similar to the Cape Cod & Nantucket sequences, but we'll see.