Monday, February 24, 2014

Team Unionid

Taxonomy is a wily beast.  As François discussed in his previous post, keeping up with who is called what can be a complex issue.  Species can be synonomized with other species, moved to other genera, split from their current species into a new species (or new genus), and back again and so forth.  This can make things somewhat complicated for museum collections, especially when we receive collections that have been collected throughout history.  We get specimens that have the ID that was correct when they were collected 50 years ago, but what is the current correct name? What is the name in our database?  Is it one of those two or one of the many steps in between?  There are a (very) few groups that have current taxonomy listings on line, but we deal with so many groups from so many phyla.  It usually takes an expert, who is familiar with the current literature of their particular group to clear things up. Fortunately for us, we know an expert for one of our largest groups, the Unionidae family of freshwater mussels, and he's recruited others.

Jim Williams, Matthew Rowe, and Jordan Holcomb have been combing through countless brown shells and getting our taxonomy in order. 

To give you an idea of what "countless" means...

Yeah, you could totally count that, but multiply it by...

That's still doable, might take a while, but...

Nearly that entire aisle is Unionids, and there are even a few cabinets worth in the previous aisle.  Let's not forget the wet collection.  Below is less than half of it.

Even though they are all caught up on the current taxonomy of this group, it still isn't always as straightforward as changing all specimens of one name to another.  Here is an excerpt of an email I got from Jordan outlining the specimen labels they needed updated and printed for the Lampsilis teres/floridensis group:

We will need everything from Florida listed as Lampsilis teres to be changed to Lampsilis floridensis.  All records from Georgia except those from Walker, Chattooga, Gordon, Floyd, Bartow, Whitfield, Murray, Gilmer, Catoosa and Polk counties listed as Lampsilis teres need to be changed to Lampsilis floridensis.  Finally, all Lampsilis teres holdings in Alabama from Butler, Barbour, Chambers, Conecuh, Covington, Crenshaw, Coffee, Escambia, Dale, Geneva, Henry, Houston, Lee, Pike, and Russell counties should be changed to Lampsilis floridensis. 

And this doesn't even account for the L. teres floridensis that we had cataloged from Iowa and Arkansas, or the L. teres teres specimens that needed to become L. teres.  So it's complicated, and we are really grateful that they are willing to spend all this time and effort helping to get our collection up to date.  We're also grateful for the bribes they bring us to keep the updated labels flowing.

Unionids are a challenging group to work with, but the challenges that they present to us pale in comparison to the challenges with which humanity has presented them.  Many species are critically endangered and some are suspected to now be extinct.  As a freshwater group, they rely on many of the same waterways that we utilize for drinking water, power, recreation, and many other uses.  Pollution and habitat loss have wreaked havoc on this group that is very sensitive to changes to their ecosystem.  If you want to know more about Unionids, check out Jim's book on the Alabama mussels, and keep your eyes peeled for his next one.

:) Mandy

Thursday, February 6, 2014

Invertebrate Zoology is Nice(ville)

This past weekend we were visited by a group of high school students from Niceville, FL.  They have come to visit us every year for the past several years to get a taste of what we do, and to incorporate some of our techniques into their own projects and fieldwork.

They divided into three groups.  The first group explored the collection for a broad overview of the kind of biodiversity we have in our collection.  Of course Bathynomus giganteus, a giant isopod, was a hit.

Who could resist a face like this?

Photo from Wikipedia Commons
We had several exercises for them down in the collection.  Jenna worked with a group of students trying to sort brittle stars.  There is a group that has been historically identified as a single species, however genetics and the discerning eye of Tania (a visiting researcher) can find significant differences between several groups within the species.  We challenged the high school students to do the same, armed with Tania's genetic tree and a microscope

The students also braved the world of tunicates with Ronaldo who is visiting from Brazil.  He showed them some nice clear diagrams with taxinomically significant features highlighted.  They then looked through the microscope at a prepared specimen to see how tiny and easily confused these features really are.

Then they tried their hand at some microscope work of their own and prepared some sea cucumber ossicle slides with guidance from Starmer John and myself.  He even brought in the big fancy microscope from our office for the occasion, to demonstrate how ossicles show up under polarized light.

The second station was upstairs in the lab with Nat and Jennifer.  After explaining the PCR process and how we use it in our lab, the students all gloved up and prepared solutions for PCRing.  Since running the actual PCR is a process that takes several hours in the thermal cycler, Nat and Jennifer ran some pre-loaded gels so they could see the bands of DNA fragments of various lengths.

After their stint in the DNA lab, the students headed downstairs to work with François on aligning and cleaning DNA sequences using Geneious.  After we send our PCR products out for sequencing, the results we get back still need some hands-on attention before they are ready for prime-time, so the students got a taste of that.  François has undoubtedly spend many an hour in front of the computer with color-coded nucleotides dancing before his eyes. 

We had a great experience with the group and it's always fun to share our love of what we do, especially with potential future scientists.  In fact, you can never be too young to be engaged in invertebrate zoology...

...even if what that means for now is that you're drawing some octopus and crabs in with your flowers.