Unisexual Ambystoma

Unisexual Ambystoma
Showing posts with label amphibians. Show all posts
Showing posts with label amphibians. Show all posts

Saturday, November 15, 2014

Required reading: What are we going to do about saving salamanders?

The fungi are coming for all the animals I love.

Frogs have declined across the world. Bats are disappearing from North America. Even snakes! From the outside looking in, our American biodiversity is a hodgepodge of invasive species surrounding smaller and smaller pockets of protected native flora and fauna. 

And now, you may be able to add salamanders to the list. Nooo!

Eastern Newt in red eft phase (Notopthalmus viridescens)

A recent publication in the journal Science describes the threat of a skin fungus that causes massive die offs of salamanders in Europe. Like the fungal pathogens that have caused declines in frogs and bats, this fungus has been introduced into areas where the local wildlife has no evolutionary history with the pathogen, and therefore lacks a natural defense with no time to develop one. In this case, the salamander fungus has an Asian origin and has recently been introduced to naive European salamanders.

So this fungus isn't even in North America? Right, not yet. However, the danger is a real one. North America is THE place for salamanders. We are the Amazon for these animals. You can walk across a few hills in Georgia and see more salamander species than you could find in a coast-to-coast trek across Costa Rica.

Credit to Clinton Jenkins

Here is your required reading if you want to know how to help and potentially make a difference:

1. This news article from the New York Times
2. This excellent editorial by Drs. Karen Lips and Joe Mendelson

Cumberland Plateau Salamander (Plethodon kentucki)




Monday, September 1, 2014

Salamander Snapchats

With the school year starting up again, it means that the undergraduate crew that I work with in the laboratory at Ohio State are back on campus. They are great to work with. Really great. One of my favorite things about them, aside from their work ethic and trustworthiness, is that they have a fantastic collective sense of humor. Because levity is a big part of my own personal work environment, I encourage joking around extensively while doing scientific work. 

One of our salamander caretakers, Paul, is particularly fond of updating me regularly about how the captive salamanders are doing. However, instead of coming to my office or sending me an email, Paul chooses to accomplish this through funny snapchats. If you don't know what Snapchat is, it is a messaging app for phones that allows the sender to create picture messages that are only viewable for a few seconds.

I thought I'd share some of Paul's work (with his permission). These messages are irreverent and silly and very funny to me. I hope you think so too.





























Thursday, August 7, 2014

First publication from SciFund support

The reason I started this blog two years ago was to connect to those who helped fund my science through the SciFund Challenge. Crowdfunding has come a long way, even since then, and I hope that my funders have been able to check back time and again to see how my PhD is progressing. However, after the t-shirts were sent and the thank-yous were written, I haven't shown much about the salamander for for which I was so graciously supported by a group of science-loving citizens.

One thing that is difficult to appreciate about science: it takes a long time. Creating new knowledge is tough. From generating new ideas to collecting and analyzing large amounts of data to having your work evaluated by your peers, even small projects can take years until the product of all that work is produced. 

I'm thrilled to finally have the first scientific publication resulting from crowdfunded support officially in press. The paper is titled "Evolutionary basis of mitonuclear discordance between sister species of mole salamanders" appeared in volume 23 (issue 11) of Molecular Ecology. If you take a look at the acknowledgements at the end of the paper, there is a specific sentence where I send my thanks to all of those who funded my work through SciFund. How cool is that!

The data that was collected for this project was done while I was in the field working on the Ambystoma dispersal project, and my Scifund support was much appreciated during the associated travel across the state of Ohio.

So, that sounds nice, but what is the science?
One thing we noticed when looking at the salamander samples that we had from all across Ohio: some of the species of salamander were showing up in weird places. Particularly, these two sweethearts:



The salamander above on the left is only found in the very southwest of Ohio and is mostly located in Eastern Kentucky. The reason? The Streamside Salamander loves to breed in small streams that don't have fish. In contrast, the Smallmouth Salamander, which is found over most of Ohio and across a wide part of the central United States, only lays its eggs in ponds and other wetlands that aren't streams. 

Here are some of the areas we find these two salamanders ("sympatry" just means they are found in the same county):

BUT, when we used DNA to identify the samples we had from across Ohio, we identified many animals as Streamside Salamanders that we were almost sure were actually Smallmouth Salamanders. 


See all that green in the middle of Ohio? That didn't seem right.

We found these animals in ponds (not streams) and they were well outside of the above range of Streamside Salamanders. Since we only had DNA samples, how could we figure out what was going on?

Because we were using tiny pieces of DNA from the salamanders' mitochondria, there were three main explanations for this unexpected pattern:

The kidney bean thing is suppose to be a mitochondria!

So, we could be observing 1) a misidentification of the central Ohio salamanders or 2) the presence of mitochondria from one species inside the other species (weird!) or 3) hybridization between the two species.

We used DNA collected from both the mitochondria and nuclear DNA of salamanders from all across the state to show that mitochondria inside of the Smallmouth Salamanders in central Ohio are invaders from the Streamside Salamanders, a biological process called mitochondrial introgression

Mitochondrial introgression happens when two species hybridize at some point in time and the mitochondria that comes from the female of one species becomes abundant in the other species, either by natural selection or random chance. As strange as it sounds, the phenomenon is well-recognized and has been identified in a diverse group of animals. 


So why is our publication important? 
First, we solve the mystery of finding salamanders with strange DNA by using a bunch of different genetic techniques. Our methods show the pros and cons of the different ways that scientists have tried to study mitochondrial introgression in the past and provides a guide for how to use these techniques.

Yellow-Rumped Warbler
Second, we took a look at all of the locations where we find salamanders with mismatched mitochondrial DNA and found that these wetlands are located in places with significantly higher rainfall during the spring and summer. This could be a sign of an adaptive link between the foreign mitochondria and a wetter environment.

Making the links between patterns of foreign mitochondria and their adaptive advantages is important and finally becoming common. Other recent publications like ours have shown both advantages (in Warblers) and disadvantages (in Long-Toed Salamanders) to having an introgressed mitochondria. Using genetic information, scientists are finding out what evolutionary processes are happening hidden from sight inside the animals of our backyards. Pretty neat.

Long-Toed Salamander






























Wednesday, November 20, 2013

A research lab that herps together, works together

Back in August before the semester began, a good portion of the Gibbs lab headed down to Florida for a week of science and reptiles/amphibians. We were visiting some colleagues/collaborators at Florida State University as well as helping Sarah Smiley catch pigmy rattlesnakes for her thesis research.

Believe it or not, I've just recently downloaded the photos from my camera. Here are some of the interesting things we did and interesting creatures we found:

I almost ordered two slices because I didn't believe that they were "as big as your head".
David and Lisle appreciating the alligators
Sarah took us swimming at Wakulla Springs. We were all brave enough to high dive. 
There I was, expecting a honky-tonk. What a disappointment.
A lifer for me: Pig Frog (Lithobates Grylio)

A handsome juvenile Cottonmouth (Agkistrodon piscivorus)



Matt demonstrating the art form of laying out "rock snakes" to trick other cars searching for snakes at night. Classic.
The snake we were after: The Pigmy Rattlesnake (Sistrurus miliarius)
Sarah studies how these snakes' venom is locally adapted to their prey

Pigmy is a good descriptor. Here are four adult snakes at the bottom of a 5 gallon bucket.
Another lifer for me: Little Grass Frog (Pseudacris ocularis). I thought the first one I saw was an insect jumping through the grass.
Sarah gets the royal treatment during the half of the year she spends in Florida at Stetson University.
It was hot and humid, but we found snakes. Left to right: David Salazar, Sarah Smiley, Terry Farrell, Lisle Gibbs, Matt Holding, Rob Denton