Wednesday, May 5, 2010

Fluid collection re-curation: What I do and why it matters

Last year our division got a collections improvement grant from the National Science Foundation to re-curate our entire fluid collection. (Specimens can be prepared in three ways: as skeletal specimens, as dry skin specimens, or as fluid specimens. Fluid specimens are fixed with formaldehyde and preserved in ethanol. They are also known as "spirit specimens" or "pickled specimens").

I was hired to execute this re-curation effort. What does this mean and why does the fluid collection need to be re-curated? The short of it is this: the specimens need to be re-jarred and their fluid needs to be changed. The data associated with each specimen needs to be entered into our database, and the specimens need new labels. Some of the specimens need to be identified. So, I am re-jarring, changing fluids, databasing, re-labeling, and identifying!

The long (but fun, I assure you!) answer is as follows. First, for the re-jarring and fluid changing: As I mentioned above, the collection is very old. This means that most of the specimens are in old mason jars that do not form very good seals, which allows the ethanol to evaporate. Some very very old specimens are even currently in jars that are sealed with pig bladders! This was a common practice in the 1800's. Here's a salamander skeleton in a pig bladder-sealed jar. This specimen came from a biological supply company in Chicago, and was most likely used for teaching purposes:

To fix the jar problem, we are re-jarring all specimens into modern jars. As we re-jar the specimens, we are changing the fluid in the jars to the modern standard of ethanol. Many different types of fluids were used as preservatives in the past-- including various liqueurs such as Anisette! I do not recommend drinking from old specimen jars, however.

With each specimen there is an associated label that includes invaluable data (the locality where the specimen was collected, the date of collection, the collector, etc.). These labels are currently attached to the outside of the jars (where they could easily fall off), or they are handwritten with ink inside the jar (where the data is fading away with time). This data could be lost forever as is. To fix this problem, we are entering all data into the museum database, and we are re-labeling all specimens with archival, thermal-printed digital labels. Yes, very high-tech.

Here's a shot of the before and the after re-curation:

As I mentioned above, I also do my best to identify as many unidentified specimens as I can, as well as catch any glaring mis-identifications. Identification is one of my favorite parts of the job, and involves lots of books and dichotomous keys.

I'll be repeating this re-curation process for each specimen in our fluid collection, jar by jar, for every bird, mammal, fish, reptile, and amphibian here. As I re-curate my way through, I'll effectively be touring my way through the vertebrate tree of life, as our collection has representatives from a good portion of the tree's branches. I feel lucky to have this opportunity.

I'll finish this post by commenting on why we should care so much about preserving these specimens in the first place, as this is not always obvious to those outside the science/collections world. Chris Norris, the collection manager of Vertebrate Paleontology here at the Peabody, speaks to this elegantly in a recent post in his blog, Prerogative of Harlots:

"In a very real sense these collections are irreplaceable, a point that often comes up when we try to figure out a basis for insuring the specimens held in museum collections. It's impossible to exactly replicate a collecting event, the multiplicity of biotic and environmental factors that mean that every specimen caught at a particular time and place is unique. Even if you can catch the same species they will be represented by different individuals, with different parasite loads, different gut flora and fauna, different stomach contents.

As we become more aware of the importance of the complex data associated with natural history collections, these small differences assume greater importance. Of course, all is not lost if you have the collecting data - the notes and observations made by the researchers at the time the specimens were caught. But these data can only address the factors that were thought to be important at the time of collection. They may not be able to address new questions asked by a future generation of researchers. This is one of the reasons that spend so my time and effort preserving specimens, and why we worry that our preservation techniques may inadvertantly close off future avenues of research."

Along with enabling important research in the future, preserving the specimens in natural history collections also enables us to verify the findings of past and present researchers, as we can study the very specimens they used to make their discoveries.

Losing one of our specimens would be akin to losing an important historical document, but worse. Documents can be easily copied, re-printed, backed up, etc., but these specimens cannot. If the original Declaration of Independence were to be destroyed, it would be a tragedy, but at least we would have copies. If our specimens were to be lost, we could not recover them in any sense.

Essentially, if we wish to understand the life on this Earth-- how it works, how it's changing, how we can keep it from perishing, how it can keep us from perishing--preserving the specimens in natural history collections is a must.

For more on the importance of preserving natural history collections, here's an excellent article on the matter by Carl Zimmer.


  1. Megan Miller cued me onto your blog. It is nice to see more people working in and trying to preserve natural history museums and collections. I teach a variety of subjects myself, and focus on ectoparasite-vertebrate interactions (namely mites and their kin on bats and rodents). Part of my job is to curate the Jim V Richerson Invertebrate Collection at our school, as well as help out with the James F. Scudday Vertebrate Collection. Welcome to the world of museum science!

  2. Miteman, thanks for the welcome! Megan has told me a bit about you in the many years we've been friends. Maybe one of these days we'll get a chance to meet! In fact, you should come to the SPNHC meeting in San Fransisco next year. I just got back from this year's meeting and it was great.