Mummichog DNA Manuscript Accepted For Review By Northeastern Naturalist

I just heard from the editor of the journal Northeastern Naturalist that the manuscript by Kris and me has been accepted for review, with a guest editor and 2 reviewers. That's usually a good sign, so I feel better already. I was afraid they might think the research was too molecular in nature.

The new moon is next Thursday, so we'll be going out on Friday afternoon to run drift nets on the Flint River. Ruth repaired the torn seam on the newer net using heavier thread and a better stitch pattern, so it should work. There's no significant rain between now and Friday, the river shouldn't be at a suicide commando level.

Looks Like It's On To Panama In May

I heard from the Smithsonian Tropical Research Institute in Panama today. They've accepted my research proposal to check out Bishop's Livebearer for gill parasites. So, now I have to firm up the details like the exact dates, housing arrangements, lab access, hopefully using their 4WD vehicles for field work, ... Last week I started the process on campus of getting approvals to spend the money for travel. A whole string of people have to sign off and approve me using allocated money for travel. I don't think anyone has a problem with it, but universities are nothing if not bureaucratic.

I did the systematics exercise in Vertebrate Zoology today. Groups of students received 8 different fish species, and looking at various external physical traits had to create a character matrix and use it to construct a cladogram to represent similarity, and presumed common ancestry. I used some local species for it from our preserved fish collection, including stonerollers, scarlet shiners, bluegills, gar, paddlefish and sturgeon. The odd thought is that I'm the only one in our department who routinely does this kind of thing, a core part of describing and understanding biodiversity (one other faculty member at least touches on this). It's a fun exercise because there's no easy, obvious answer and everyone has to think about it. I pointed out to them that biology in particular, and science in general, is one long argument so they should certainly debate any presented outcomes.

Estill Fork, With Snow On The Ground!

Well, not lots of snow, but I think it's the first time I've been there with any snow on the ground. Water temperature was 6 deg. C, and air temp was about 0 deg. C when we arrived. We went primarily to do the darter habitat partitioning survey work for Brian's thesis work, and also to get darters for Robert's darter gill parasite project. Six people went, which made it relatively easy, me, Brian, Robert, Doug, Jeremy and Heather. We found many more fish than on previous visits, largely because our take of rainbow darters was huge including many juveniles. Also, we found lots of both stripetail and fantail darters, including a large number of juveniles in a few locations in our transects. It was cold but not unbearably so. In the first picture below, Robert and Doug do their respective tasks of timekeeping and data recording while Brian is in the stream taking depth and current flow readings.

Here's my traditional shot looking across Estill Fork to the east from where we park. The stream was full today, unlike our last visit in November when it was in low flood.

Brian prepares for our first transect.

Brian doing a current flow reading, while Jeremy on the far shore pretends to hold the end of the survey tape. Notice how clear the water is around Brian, in a spot where the water is about 40 cm deep. That's the area where we found lots of juvenile stripetails, and to a lesser degree juvenile fantails; they were even more common about a meter closer to the near bank where the stream ran through a hole about 70 cm deep.

Mummichog Manuscript Submitted To Northeastern Naturalist

I just submitted the manuscript, "Phylogeography of the Killifish Fundulus heteroclitus (Mummichog) Based on the Cytochrome b Gene", to the journal Northeastern Naturalist, authored by Kris Stanton and myself. Hopefully they'll like it, as long as they don't think it's too molecular for their focus. If so, well, we'll take it from there.

Sculpture Follow-Up

I found out the artist and name of the "minnow trap" sculpture in front of the Shelby Center. The artist is Michael Cottrell from Jacksonville State College in Florida, and the sculpture is titled, "Valence". I wrote him and told my impressions, which I think favorably impressed him. His response to me is below:

"Bruce,
Thanks for your kind words. We thought the piece might be well suited to the science building, and I am glad that is indeed the case. I hadn't thought of minnow traps...but now that you mention it... Its good to see that the art can appeal to a diverse group, and it is perfectly normal to project a bit of yourself into what you see in an abstract sculpture.

If you are interested, the website for the sculpture tour which highlights all the pieces in the exhibition and their locations is:
http://www.spacessculpturetrail.org


Thanks, ----Michael"

Male Shiners May Have Relatively Larger Brains?

I took the opportunity of a second snow day today to chug through some very detailed data we've generated about brain size in telescope shiners. Brittany, Alexandra, and I think Andrew measured the overall brain and the volume of individual brain structures from each of 10 male and female telescope shiners from each of April and June, the beginning and peak of their spawning season at Estill Fork. Looking at averages, and average ratios such as brain volume to standard length, I teased out some patterns. While female telescopes are longer and heavier on average with larger brains, in both months males had larger ratios of brain mass to net body weight (not counting gonadal mass), the volume of the optic tectum to total brain volume, and the ratio of optic tectum volume to standard length. These ratios weren't always statistically significantly different using a two-tailed t-test. We have found basically the same patterns with scarlet shiners. What's interesting is that the optic tectum is a relatively large part of the brain that processes visual information and helps the fish to move in three-dimensional space. As mammals we have them too, but they're much reduced.

The big question is, as always, what does it mean? I think it reflects the fact that male vertebrates have a much wider variation in reproductive success than females, and for stream fishes this is strongly linked to the ability to find and hold optimal position for spawning. Telescope shiners aren't strongly sexually dimorphic like scarlet shiners, and males don't guard territories to attract females. But males have to be able to show up in spawning aggregations and not be muscled out, which is largely an information processing exercise. My working hypothesis is that it's advantageous for males to have relatively larger brains, especially the optic tectum, as the result of long-term sexual selection pressures producing large-brained males. Does that mean they're smarter than females? Not exactly, but they may be more agile swimmers, which is a hard thing to quantify I suspect. Now I have to pull out our scarlet shiner data and look at it more closely, too, and try to mesh the two data sets together in a coherent fashion.

School actually starts tomorrow!

The Mummichog Manuscript Is Just About Ready To Go

I took advantage of the snow day today to do a final round of polishing on the manuscript by Kris and me, "Phylogeography of the Killifish Fundulus heteroclitus (Mummichog) Based on the Cytochrome b Gene". One good sign is getting it down to 18 pages as I've slashed soft verbiage and redundancy. With any comments from Kris, and a last round of checking the format so that Northeastern Naturalist will like it, I'll send it out.

We got six inches of snow in Huntsville overnight, which is about as much as get in a typical year. Today was the scheduled first day of the spring semester, but that didn't happen as everything in town was shut (no snow plows!). I feel lucky that we were able to get out last week to do various stream work, ahead of what's likely to be this week's wintry weather.

Southeastern Naturalist Accepts Paper For Review

I heard from Southeastern Naturalist today about the Dactylogyrus & Telescope Shiners paper. The editorial board has agreed to send it out for full review with an assigned guest editor and probably two reviewers. This is good, and usually means that they'll accept the paper as long as reviewers' comments are addressed. I hope so.

A High-Water Trip To The Flint Today

It rained about 4 inches here on New Year's Eve into New Year's Day, and the rivers all flooded. Today we went out to the Flint River to run the driftnets, since it's the new moon. The water was higher than ever, but not quite too high. We tried to set a driftnet at one of our standard places, but the high, fast water quickly tore a side sleeve and it started to disintegrate. The water was probably moving almost a meter/second. The picture below shows Robert, Jeremy and Brian grabbing parts of it before it disappeared downstream.

So, we set the other driftnet in a quieter area that still had a current of about 0.4 meters/second, a pretty good pace. It still took three of us at a time to hold it in place. Below is a picture of the drift being transferred to a jar at the end of an hour. With six people taking turns, this wasn't so bad.

Fundulus heteroclitus paper almost ready to go

I've been plugging away at editing Kris' thesis on cytochrome b mitochondrial DNA into journal format, and I think I'm almost there. Below is the current version of the Abstract.

ABSTRACT

The mitochondrial cytochrome b gene from seven populations of the killifish, Fundulus heteroclitus, was examined for single nucleotide polymorphisms and haplotypes. Three populations were from New England, two from Virginia, and one each from South Carolina and Georgia. In the gene sequence of 775 bases examined, 16 SNPs were found which defined an expected distinct northern haplotype. A Virginia haplotype defined by five SNPs was also found, separating them from populations further south. Phylogenetic analysis using Bayesian inference supports a north/south divide. The genetic distance between the three northern populations and the four southern populations was 1.5%. These findings support the hypothesis of post glacial rapid leptokurtic migration of F. heteroclitus to the north from southern refugia ~13,000 years ago. This caused a genetic blockade within the species, leading to the lower genetic diversity found in modern northern populations compared to southern populations.