Tuesday, March 30, 2010

Drifting Aquatic Invertebrates of Estill Fork Poster

Brittany is showing our poster tomorrow at Alabama A&M for the annual meeting of the Alabama Academy of Science. This will be 10-12 at Elmore Gym if you happen to be around. You can click on the poster to see more detail. The original is 39 inches by 32 inches, so this is unavoidably a reduced view.

Friday, March 26, 2010

Andrew Is Going To Iowa, And A New Abstract

Andrew heard from Iowa earlier this week, offering him admission to their Doctoral program in Evolutionary Biology. They also offered a generous stipend. So, Andrew will be heading off to Iowa City later this summer. It really is good news!

Andrew is also entered in a state-wide contest of university students who have done research projects. He'll present our gill parasite work to the judges and an audience on Tuesday, April 6. Below is the Abstract, which is very similar to what we're writing up for publication.

Seasonality and Reproductive Impact of Dactylogyrus Gill Parasites upon the Minnow, Notropis telescopus.

Dactylogyrus is a holarctic genus of trematode flatworms that infect the gills of cyprinid fishes. Dactylogyrus species are usually highly host specific, and little is known about their life history. The purpose of this study was twofold: to determine whether Dactylogyrus exhibits seasonality in its life cycle, and if there is any effect upon reproductive effort of the host as a result of Dactylogyrus infection. We examined 383 Telescope Shiners, Notropis telescopus, collected from February to September, 2007, and October, 2008 to January, 2009, finding a total of 967 flatworms, Dactylogyrus spatulus. Parasite counts yielded a peak in the average number of parasites present per fish in May, a significant relationship between host length and infection, and a negative correlation between higher parasite load and gonadosomatic index (GSI). Parasites per fish averaged about 1.5 from August to February, with an average high of just under 6 per fish in May.

Tuesday, March 23, 2010

Various busy-nesses

It's been almost a week since I updated here. I sent my revised flame chub manuscript back to the editor on Friday, I think I addressed all of the reviewers' concerns (most of which I agreed with and thought were good suggestions). And I received a list of editorial queries from the editor of the black darter paper, which I have to sit down with again in the near future. But even more immediately I have to finish a review of a manuscript for another Southeastern Naturalist editor. I received it two days before the shooting, read it the day before, thought it pretty good and was prepared to write that, and then everything was of course thrown off track for the last month. So I have an extension for that review to next Wednesday instead of tomorrow, and have to get myself in gear to do it.

Brittany has pretty much assembled a poster for the Alabama Academy of Science meeting next Wednesday. We have a good data set with the first seven months' worth of driftnet data, so we can tell a good story. We're still working on exactly what does it mean; basically I think what we've found is that the community of macroinverts is in general stable, but every other month or so one or more groups largely expands or contracts in number. This isn't a big surprise, of course, but the patterns are interesting, like the Ephemeroptera tending to vary as do pH and alkalinity as physical parameters (shown in Principal Component Analysis, PCA). It's real biology, what can I say?

Wednesday, March 17, 2010

Estill Fork Trip, March 15

I went out with Taito, Joe and Brittany from my lab yesterday to Estill Fork to make our monthly new moon driftnet collection of inverts and also to catch some fish. Taito who took the pictures didn't get any of the driftnet set-up so we'll move on to the fish collecting... We're interested primarily in telescope shiners (Notropis telescopus) from this system for a study of how fish brains may change between non-breeding and breeding seasons, especially differences between males and females, and sexually dimorphic species (like scarlet shiners) and sexually monomorphic species (like telescopes). March is an in-between month for breeding or non-breeding for these species.

Yesterday the site had high water, but not quite dangerously high, with an air temperature of about 48 deg. F and water temperature of about 45 deg. F. We caught most of the fish shown in the following pictures where the riffle system flows into the deep pool. In the summer we wade through it with a seine, but nose-deep water is too much this time of year.

Here's the view of the low roadway across the stream, historically a ford. Usually water doesn't overtop it. Over and beyond the ridge in the background is the Walls of Jericho tract, a de facto wildnerness owned by the state.

Here's myself, Joe and Brittany examining a net haul from just downstream of this small island. This was Joe's first fish-collecting trip.

This was one of our better hauls. The silvery shiners are mostly telescopes, with one tennessee shiner right in the middle. The larger, less silvery shiners are striped shiners, and there's also a number of fantail darters in this haul including very gravid females.

And finally, a photo of shiners caught in the act of flopping around on a hand. The top silvery one is a telescope, with a striped and scarlet going clockwise.

The next new moon is Wednesday, April 14, hopefully we'll be there.

Sunday, March 14, 2010

Driftnet Project Abstract For Poster

The Alabama Academy of Science is having its annual meeting at the end of next week at Alabama A&M University in Huntsville. Brittany is putting together a poster of her work on the driftnet project at Estill Fork, July through January, to be shown at this meeting. I'm not even sure of the title of our project, but here's the abstract we're submitting for this poster:

This study examines the community structure of drifting macroinvertebrates in a stream riffle system in pristine Estill Fork of the Paint Rock River in Jackson County, Alabama. Monthly samples were made within two days of the new moon using a drift net between July, 2009, and January, 2010. Living individuals and their exuviae were identified to Order. Measurements were made on-site of stream temperature, flow rate and total dissolved solids, and lab measurements were made of sampled stream water phosphates, ammonia, alkalinity and pH. Statistical analysis using chi-square tests showed that most months differed significantly from expectation in the number of invertebrates per water volume, and each month showed a deviant maximum or minimum from expected in one or more taxonomic Orders. Ordination analysis using Principle Components Analysis of number of individuals collected per Order and stream physical parameters for each month showed that each Order responds in a different way to changes in stream physical parameters. Monthly collections of drift net samples and water samples will continue through this June to complete a year’s observation of fluctuations in macroinvertebrate community structure at this site.

Saturday, March 13, 2010

Kris' Maters' Defense Went Well

Kris presented his research yesterday at noon in one of our intro biology teaching labs that has an installed projector. About 35 people showed up which is a good-sized Masters' defense at UAH. His work was on the phylogeography of the mummichog, Fundulus heteroclitus, as indicated by comparing sequences of the cyt-b mitochondrial DNA gene. I think we have a good case showing a 100% certain separation of the New England samples from southern samples as determined by 10,000 bootstrap replicates of our UPGMA treebuilding algorithm. The odd thing we've found is that the Virginia Beach and Chincoteague, VA, samples are their own well-resolved clade within the broader southern group including Charleston, SC, and Sapelo Island, GA. Kris has to do some rewriting of his thesis to flesh out and clarify certain parts such as our DNA extraction methods, which in truth I did most of some years back in this 15 year project(!). I'll have to post a picture of our final tree with the strengths of each node in the near future. And I'd like to once again thank Dustin Smith of Columbia, SC, for his help in collecting mummichogs from the Ashley River in Charleston, SC, six years ago whose DNA became part of this study.

The weird part of the day was that as the thesis committee was finishing up our meeting with Kris after the seminar, some of our office people came down obviously flustered and told us that the Biology department was urging people to leave the building. As Kris was giving his talk, the Huntsville Police were serving a warrant at Amy Bishop's house looking for explosives, apparently, and a remote-controlled robot detonated two "bombs" found in the house which were at first reported as actual bombs rather than controlled explosions of suspect devices. The news went out as bombs found, at first, and everybody freaked out that this was part of some kind of bombing campaign by Amy Bishop's husband Jim Anderson. So, we quickly signed the papers as a committee saying that Kris conditionally passed pending thesis changes, and we all left the building and went home. That's a measure of how edgy people are of late.

Tuesday, March 09, 2010

The "Curto Method" Of Western Blotting Seems To Work

Ernie Curto, working in the Neuro Lab here, brainstormed a method for doing western blots that allows more samples to be tested in less time, using fewer antibodies and other resources. Andrew and Taito did a run of western blotting on some of the fish brain lysates we've collected this winter along with past samples and positive controls, and were able to run three replicates of each samples on (I think) 13 individual fish. Basically, it runs dot samples of each replicate on the membrane that are defined by holes punched in tin foil, allowing the samples to be lined up closely but still separately. Westerns are a form of antibody-antibody application, after which your protein sample (NMDA for us) is more heavily attached to antibodies the more concentrated it is, and then these antibodies hold onto a stain that allows different concentrations to be visualized in a scanner.

Our results were consistent with what we've found before, i.e., male scarlet shiners have lots of NMDA in their brains even in winter (it's for learning and memory channels in brain neurons), while telescope and silverstripe shiners, male and female, have less. We also included a male tennessee shiner that we captured at Estill Fork. This is a very sexually dimorphic species, maybe more than scarlets even, and the male we tested had an even higher NMDA level than the male scarlets. This reinforces our working hypothesis that species with more pronounced sexual dimorphism (like breeding colors and size) should have even more extreme levels of NMDA in males. Taito and Asuka are going to rerun our samples in a more traditional western blotting to confirm the Curto method results. If the results hold up we may sample fish on a monthly basis this breeding season to monitor how NMDA levels vary, since our costs and required effort just dropped dramatically.

Friday, March 05, 2010

Scarlet Shiners From A Now-Altered Creek

I went out to Limestone Creek along Mooresville Road today with James and Taito. It was a beautiful early spring day, sunny, high in the mid-50s F. When we arrived at our usual site we found that the banks on both sides had been bulldozed, and the ford connecting the two banks had been scraped such that the small shallow island on the far bank from the road is gone. This is bad for us since scarlet shiners prefer flowing pools near, above or below faster moving water. The current set-up is mostly fast-flowing water, almost like a mountain stream even though this site is fairly close to the Tennessee River in Limestone County to the west of Huntsville. But we went out anyway, and quickly realized that the scarlets were in one pocket of slower water immediately downstream of the former island. We were able to net about 23 of them without too much trouble once we realized where the sweet spot is now. We did some work upstream, but found those fast waters now to be loaded with darters (which is good, of course) but no shiners. People around here have a mania to "improve" streams with channelization, which only makes flooding events worse because the waters can really move fast and erode banks, mobilize sediment, etc.

Anyway, here's what it looked like today. The first shot looks across the historic ford here, now all nice and muddy. That should help with sedimentation in the creek, to leave muddy banks like this.

Here are James and Taito moving into the creek after pussyfooting through the muddy banks and not sliding in. The slow flow spot is to the right, downstream in this picture.

Andrew was in the lab much of the day working on a western blot run using the new, hopefully improved Ernie shortcut technique with some of the telescope and silverstripe brain samples we've collected over the winter. The scarlets we collected today are the final collection for this project, as the "nonbreeding" season is ending locally. Hopefully we can have a clear idea on the NMDAR levels in the fishes' brains in the next several weeks.

Thursday, March 04, 2010

Fish Brains In Process

Andrew, Taito, Brittany and Alexandra all worked on various aspects of fish brain measurement today. They defrosted the telescope, silverstripe and tennessee (1) shiners, removed the brains and put them in a lysis buffer with protease inhibitor, sexed the fish (tough out of season, by definition) and worked on measuring the brain size of other fish collected at the same time but fixed in formaldehyde. It's some serious biology done in a burst of activity. They ran concentration assays on the lysate solutions with brains, and got protein readings up around 35 micrograms per milliliter which is impressively high. Tomorrow they'll start trying Ernie's "spotting" technique for western blotting, which will hopefully work well since it would be a serious shortcut in the process.

The last piece of this process is fresh scarlet shiners which we'll go out for tomorrow afternoon at Limestone Creek. This is the end of the "nonbreeding" season, spring is just beginning to really kick in locally.