Saturday, November 29, 2008

The Estill Fork Trip Was A Scrubout

We finally left for Estill Fork on Wednesday late, since James was stuck in a dentist appointment, and proceeded to find almost nothing at Estill Fork. Nothing that we wanted, anyway; we caught lots of striped shiners and stonerollers, along with many juvenile darters, but only two scarlet shiners and no telescope shiners. I knew we had to wrap it up when Alexandra took a major spill and soaking, after James' friend Katherine had slid down the bank into the water with no waders on. Gack. It's obvious that our target shiners go through a major habitat shift when the water gets cold, as it was on Wednesday at 8 deg. C. There's a deep hole at this site that we couldn't possibly seine without going into neck-deep water, so for all I know that hole was loaded with shiners.

I hope to get back there on either Friday, Dec. 5 or Friday, Dec. 12. My big plan is to work some sites downstream from where we've been going, accessible from the county road along the west edge of the stream. I hope I'm right!

Wednesday, November 26, 2008

Out To Estill Fork Today

Three of us are going to Estill Fork today to collect telescope and scarlet shiners. It's freezing right now, but the forecast is for a high temperature over 60 deg. F with clear skies. There hasn't been rain for almost a week, so the fork shouldn't be too high.

Jennifer came by yesterday and gave me the poster of the scarlet shiner 11-ketotestosterone work she did, and won a student poster competition at the SFC meeting in Chattanooga. I've tacked it to the wall outside of my office. Hopefully no one objects to this, since it breaks the bland tedium of our office loop.

Friday, November 21, 2008

Odds & Ends

Fundulus bifax update: we're making another push to get our purified PCR products sequenced. We've given up on Operon for the moment since we keep talking with the same tech who doesn't know what cytochrome-b is near we as can tell. So, we'll be sending off some bifax DNA along with Kris' four heteroclitus samples from Nantucket to MC Labs in San Diego, who come highly recommended from some colleagues. Between that and a few tweaks to our purification / concentration procedures we hope to get everything done sooner than later. Note: if you ever call MC Labs on the phone, they don't think it's funny that you refer to them as "Mac Labs"; it's M C Labs. Really.

I realized yesterday that we have about 30 scarlet shiners from Limestone Creek last month that we never measured. That'll hopefully be done soon; hey Andrew, are you up for some gut content analysis?

I got an email from Joe Scanlan today, asking how the bifax project is going. He was especially curious if we're up for any studies involving his aquarium-raised fish. There is a range of possibilities for work with such fish, especially along the lines of what we've done with shiners of late. But this would require a student or two to help push through, we'll see who's up for it.

And you'll be happy to hear that my orange-spotted sunfish are extremely well-fed and growing. They're pugnacious little suckers, too, which makes them interesting aquarium fish. They pay attention as you move around the lab in their view. And if you throw small earthworms into their tank, you have their undivided attention.

Monday, November 17, 2008

Jennifer's Poster Won The Student Competition At The SFC Meeting

Jennifer entered a poster in the student poster competition at the annual meeting of the Southeastern Fishes Council in Chattanooga, TN, last Thursday and Friday. She won the competition for best poster, which is great. The poster, based on her thesis work, was titled “Relationship between 11-ketotestosterone and reproductive status in Lythrurus fasciolaris.” She was happy to meet and talk with many of the attendees about this project. I guess many of the attendees thought that using scarlet shiners as a model study organism for neuroecology is a good thing; and I'm glad for that, because people at this meeting would actually know what a scarlet shiner is in the first place. I hope to have a copy of the poster hanging here at UAH in the near future. Hooray!

Friday, November 14, 2008

Male Telescope Shiners Have Relatively Larger Brains

Yeah, it's true, based on examining telescope shiners we collected at Hurricane Creek in April and June last year. We have a sample size of about 20 for each month, 10 females and 10 males. What we've done is calculate brain weight as a fraction of somatic (body) weight, and graph that against standard length. So the graph below shows three interesting relationships. First, that males have a relatively larger brain at a given size, and second, that relative brain size decreases with increasing length, so that a very big (always female) telescope shiner has a brain that makes up about 1% of total body mass. So here's the graph. The males of both months each have a short line, because males only get so big, while the longer lines are females since they attain a significantly larger size than males (the opposite is true with scarlet shiners). And thirdly, notice that the linear regressions reported for males have very low R-squared values compared to the females. This means that relative male brain size is much more variable than that of females. This would be expected, since in any vertebrate species males have much more variable reproductive success because of variable phenotype. We haven't found any reference to anyone else observing such a relative brain size to body length relationship. (The image appears in a separate window if you click on it.)

Monday, November 10, 2008

Telescope Shiner Brain Size, Preliminary Data

I had a chance today to sit down and fool around with our raw data from measuring the brains of telescope shiners from Hurricane Creek captured in June, 2007, at the Walls of Jericho. The one relationship I think I've nailed is brain mass/body mass, i.e. how big is the brain as a fraction of body weight. Using a t-test to compare 10 males to 10 females, relative male brain size is significantly larger with P<0.001, a very significant difference. This is the same basic relationship we've found with scarlet shiners. But male telescopes aren't brightly colored like scarlets, and females are larger than males. There is evidence that specific brain regions like the optic tectum are also larger in males than females, but I don't have the numbers to ice it. We're on to something, but I'm still not sure what(!). I'll certainly keep you posted.

Saturday, November 08, 2008

Some Stan Sung Photos, Including From Estill Fork

I received a CD from Stan Sung yesterday with photos from his trip to 'bama last month. He's mastered the art of using a small photo tank to get quality fish photos. Below are four photos. The first one is Brittany, Jennifer, myself and Stan at the low causeway over Estill Fork in Jackson County, AL, last Oct. 25. As you can see, it was a drop-dead beautiful day.

I haven't had a good photo of a redbreast sunfish, Lepomis auritus, since I realize that I don't always attention to them when we catch them. Stan took the photo below of a redbreast from Estill Fork.

The next two photos are of fish Stan and company found in Cypress Creek in Lauderdale County, AL. Where they went is the one spot in the state where I know that warpaint shiners, Luxilus coccogenis, are easily caught. They're striking fish, even out of peak spawning season.

The entire Cypress Creek drainage also has lots of rosyside dace, Clinostomus funduloides. This species has disappeared from much of the northern edge of its range in Ohio due to the alteration of creek habitats by humans. It still seems to be doing well in north Alabama.

Thursday, November 06, 2008

Defrosted Fish Can Give Up Their Brains

Sounds weird, but it's true. On Tuesday we ran a dress rehearsal for removing brains from freshly defrosted fish. We defrosted a small telescope shiner from our collection at Estill Fork on Oct. 4. It only took two minutes for the fish to be flexible, as good a sign as any of defrosting. It was 25.5 mm long, and it took Brittany about 5 minutes to make a clean removal of the brain. The brain was kinda mushy, certainly compared to formaldehyde-fixed brain, but it came out in one piece. We were able to weigh it, at about 0.01 gram out of a total fish mass of about 0.2 g. So the brain is roughly 5% of somatic mass, consistent with what we've seen in scarlet shiners.

Our plan is to stage a brain dissecting party in the lab next Thursday afternoon. We have frozen Estill Fork fish from both Oct. 4 and Oct. 25. We have to quickly defrost a fish, weigh and measure it, remove the brain, weigh the brain, and immediately place it in a tube of lysis buffer on ice. We're doing this to assay the brains for the cellular protein NMDA via Western blot, so we don't want any protein degradation before the tissue hits the buffer. We have no idea of what to expect for NMDA levels in juvenile brains compared to adults, I'm not sure anyone has ever tried this with juvenile fishes compared to adults.

I hope that everyone has recovered from the elections. I'm happy with the results, I sure as hell hope you are too!