By Crystal Ernst, PhD Candidate (McGill University)

Since I finally submitted my manuscript to a journal (YAY!), I’ve been tying up the little loose ends remaining at the end of the project. You know: organizing the useful data and image files, tossing the files marked “MESSING_AROUND_WITH_DATA_v.29), tidying up my R code, and, perhaps most importantly, curating my specimens.

I’m not going to go into too much detail about the project here (I’m saving that for another post). I will say, though, that the work I just completed includes just over 2,600 beetles from a single location in Nunavut (Kugluktuk, where I spent my entire first field season).

Two major aspects of the physical work (as opposed to the thinking, reading and writing) involved in an ecological/entomological project such as this one are the pinning and the identifications. Some of the tasks are a bit tedious (cutting labels; entering data; gluing over 800 specimens of the same tiny, plain black ground beetle to paper points), and some of them are thrilling (finally getting over the “hump” of the morphological learning curve and feeling good and confident when working with your keys; having experts tell you “Yep, you got those all right”; discovering rare species or new regional species records). In the end, in addition to the published (*knocks on wood*) paper, you have boxes or drawers full of specimens.

The specimens are gold. (Read this post by Dr. Terry Wheeler to understand why.)

Unfortunately, they don’t always get treated as such.

In the two-ish years that I’ve been working in my lab, we’ve had two major “lab clean-up days”. The first managed to get rid of a lot of clutter (old papers, broken apparatus, random crap). The second involved going through the “stuff” that was eating up all the most valuable storage space: specimens. Years and years worth of graduate and undergraduate projects’ specimens, stashed in freezers, boxes, bags and vials of all shapes and sizes.

Some things were in good shape (pinned well, or in clear ethanol). Other things were, well, downright nasty: gooey beetles in sludgy brown ethanol, dried up bits of moth wings in plastic containers, and a little bit of “what in the name of pearl is growing on that agar plate???” in the fridge.

None of these items were kept – their value as useful specimens was nil. So, the physical representation of some student’s work – probably months or years worth of work – was tossed in the trash.

Others, happily, were tucked back into drawers and cupboards, because someone had taken the time to ensure the specimens were well-preserved.

However, even many of these were suffering from a serious issue: bad labels.

Allow me to illustrate the point. This is a bad label:

This is also a bad label:

The first, you’ll note, is written in ballpoint pen (which fades) on a torn piece of notebook paper and contains almost no information. The second, although it looks fancier and perhaps more sciencey, is just as bad: it contains a cryptic code that is useful only to the bearer of the lab notebook in which said code has been written down. Or, perhaps the code is completely intelligible to the researcher who developed it, but the key to it exists only in his or her head.

To everyone else, it is meaningless. Neither of these labels indicate who collected the specimen, where, when, or how. And we all know what happens in labs: upon completion of their degrees, students move on, email addresses change, notebooks are misplaced, data files are not backed up. The labels’ codes can never be broken, and the scientific value of the specimens – *poof*.

While there’s nothing wrong, in theory, with using labels like these temporarily (although there is always a risk that they will be misinterpreted or misunderstood after a little while, even by the person who wrote them), they are absolutely useless as permanent records.

These are good labels:

These labels, properly affixed to a specimen, provide clear and universally understood information. One provides the location, including GPS coordinates, a method of collection, a date, the name of the collector(s). The information that goes on this label can vary a bit (it may include information about the habitat or host plant, for example), but those are the basic requirements. The smaller label is typically affixed on the pin below the first, and contains the specimen’s scientific name and the name of the person who identified it (it is the “det. label”, i.e., “determined by”). These labels, and therefore the specimen with which they are associated, will remain useful for decades, even centuries.

I am totally guilty of both of the offenses I just explained (the gooky vials of nastiness and the bad labels). For my undergraduate honors project, I identified close to 8000 spiders, mites and insects to the Family level – it was hundreds of hours of microscope work. Then I stuffed all those specimens back into vials with cryptic little codes, like V-1-F(!), hand-written on STICKERS(!), which I placed on the LIDS(!) and not even in the vials themselves(!). Oh, and I’ve long since lost the notebook that contained my decoder key(!). THIS IS ALL SO BAD. I have no doubt that those boxes of vials, which I once prized so highly and felt such pride for, have been unceremoniously tossed in the trash by my former advisor.

Well, I’ve learned from my mistakes, and from working with museum and other collection specimens. I now understand that each specimen is deserving of respect – it’s the original data after all – and that means it should be properly preserved, and labelled.

So.

Last week I spent a great deal of time, as I said, tying up my loose ends. The last thing I needed to do was remove my cryptic labels (the second in the series up there is an actual example of one of my own “secret code” labels) and replace them with proper ones, sorting and tidying up the collection in the process. The end result?

This:

Frankly, it’s a thing of beauty. It’s also enormously scientifically valuable. These specimens will be deposited in various nationally-important collections and museums, like the CNC.

As a matter of fact, just last week I was at the CNC, and I saw specimens bearing the name of the last person to do a comprehensive survey of the insects in Kugluktuk, back in 1955. That tiny but so-important label suddenly made me feel connected to the man who, almost 60 years earlier, had stood on the same stretch of tundra as me, holding and perhaps delighting in the very specimen that I held in my own hand.

Giving my specimens the respect they deserve is worth it, not only for the scientific value, but also because perhaps, 60 years from now, another grad student will discover my name on a specimen’s det. label. Perhaps she, too, will feel that same wondrous sense of connection to the the greater scheme of scientific discovery…

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Original post at: http://thebuggeek.com/2012/06/25/respect-your-specimens/

Stick Insect Baculum extradentatum

Physiology Friday is a monthly column by UWO PhD candidate Katie Marshall and will feature new Canadian research on insect physiology.

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Nitric oxide (NO) is usually overshadowed in fame by its more famous cousin laughing gas, but it’s difficult to think of many simple molecules that have such a variety of important biological functions.  While NO only lasts a few seconds in the free gaseous state in the blood, it has been implicated in processes that involve everything from immune function to neurotransmission.  One important role for NO is in the cardiac system, where it functions as a vasodilator and in vertebrates it slows heart rate, while in insects it has the opposite effect.

Stick Insect Baculum extradentatum

Baculum extradentatum photo by Sara da Silva

Most of the research about the physiological functions of NO has focused on vertebrates, but recent work published in the journal of Cellular Signalling by graduate student Sara da Silva and her postdoctoral fellow mentor Rosa da Silva in the lab of Angela Lange (University of Toronto Mississauga), has shown that, unlike other insects, the Vietnamese stick insect Baculum extradentatum can respond to NO like a vertebrate.

“Our initial research interests in cardiac physiology were influenced by earlier work indicating that stick insect hearts are innervated and can be modulated by endogenous chemicals [like NO],” says study director and University of Toronto Biology professor Angela Lange.  “It is for this reason that we chose this understudied organism, which contains a simplified cardiovascular system that can be considered a model for work on other cardiac systems.”

The researchers first attempted to find the natural source of NO in the stick insect by removing hemolymph (blood) samples and staining for the presence of an enzyme that produces NO.  Then they examined the effects of NO on heart rate by dissecting the dorsal vessel out and maintaining it in a Petri dish with physiological saline.  They could measure heart rate through the placement of electrodes on either side of the dissected heart, and monitor the effects of various chemicals on the cardiac activity of the stick insect.   They also could examine whether heart rate was mediated by the central nervous system by leaving the nervous system attached or not.

insect heart rate

The effects of nitric oxide on the heart rate of B. extradentatum. Figure 3 from da Silva et al. 2012

They found that the hemocytes (blood cells) of the stick insect were producing an enzyme that was similar to the enzyme other animals use to produce NO.  In addition, the more of a chemical called MAHMA-NONOate (which produces NO) they added, the slower the stick insect hearts beat.  This surprising effect was completely opposite to what had been found in other insects and was more like the response of the vertebrate heart.

“Insects have evolved different strategies depending upon life history, and have co-opted different messenger systems for this success,” says study author da Silva. “We need to understand the full ecology of all species to finally appreciate the factors involved.”

Using the same setup, they also tested other components of a system of compounds that they thought might be involved in the pathway that produces NO that leads to decreased heart rate in B. extradentatum.  They believe that NO is produced in the hemocytes, travels to the wall of the heart, and then leads to the production of a messenger molecule that decreases heart rate.

Schematic diagram of the proposed regulation of cardiac activity in B. extradentatum by the gaseous signaling molecule, nitric oxide (NO)

Schematic diagram of the proposed regulation of cardiac activity in B. extradentatum by the gaseous signaling molecule, nitric oxide (NO). Figure 7 from da Silva et al. 2012.

“This study further emphasizes the evolutionary links between the physiological processes of vertebrate and invertebrate systems,” says da Silva. “Our findings suggest that signaling molecules (such as NO) common to both types of organisms can have similar effects on cardiac activity.  These novel findings demonstrate that the study of vertebrate systems can be complemented with studies in model invertebrate organisms.”

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da Silva, R., da Silva, S.R. & Lange, A.B. (2012). The regulation of cardiac activity by nitric oxide (NO) in the Vietnamese stick insect, Baculum extradentatum, Cellular Signalling, 24 (6) 1350. DOI: 10.1016/j.cellsig.2012.01.010