Paper

I don't normally feature my own academic research on this blog, but since this is directly related to my interests in preparation, I thought I would mention the following paper:

A complete protocol for the preparation of chondrichthyan skeletal specimens. S. Enault, C. Auclair, S. Adnet and M. Debiais-Thibaud. 

that was published a couple of months ago in the Journal of Applied Ichthyology. Of course, my own methods are more or less continually evolving as I like to refine my own protocols and experiment with new things, but given the scarcity of literature dealing with this subject, I think it might be of interest to some people.

Greasy stuff

Grease is a prominent issue when dealing with bones for a variety of reasons : conservation (the grease might turn acidic, which can in turn damage the mineral part of the bone structure. It can also provide a growth media for mold or fungus.), aesthetic (greasy bones are usually yellow or brown, unpleasant to look at and handle), smell (ever smelled a cupboard/room full of greasy whales ?) and so forth. On the other hand some people and museums go light on the degreasing due to a belief that bones that have not been degreased hold together better in the long run. While there might be some truth in this, I think specimens must at least be superficially degreased to avoid to have bones literaly oozing grease. The amount of grease present in a specimen varies depending on a variety of factors: species, season, age, sex, etc.

I'm currently working on a couple of nicely greasy fish, so I figured it would be a nice occasion to illustrate the issue.

Flathead catfish (Pylodictis olivaris)

First one is a partial flathead catfish skeleton, straight out of the beetles (not beetled by myself). It's not overly greasy, but you can still see the various shades of yellow and brown clearly asking for some degreasing.

American eel neurocranium (Anguilla rostrata), occipital view

Here you can clearly see liquid grease oozing from the basioccipital area. This specimen was also beetled. Maceration usually gives a head start on degreasing over beetle cleaning but results in the disarticulation of the specimen.

Mahi mahi (Coryphaena hippurus) neurocranium degreasing

I always use acetone to degrease fish material. It should be handled with care but it works very well for small vertebrates. Other degreasing techniques, especially a prolonged soak in warm water and detergent are more appropriate for larger specimens.

Ink and labels

Labelling specimens may seem pointless when you have a couple of skulls on a shelf, but it becomes absolutely essential when you start to have specimens all over the place. And while you might think that the choice of the pen you use to write down each specimen ID doesn't matter, it actually does. I recently realised that the ink on the labels on some of my specimens was starting to fade, probably due to light exposure. Turns out commercial pen should be avoided, and that "archival pens" (using pigment based ink instead of dye based ink) are much more suited for that purpose. So you might want to consider this when labelling your specimens, especially since light exposure is not the only thing that might threaten your precious identification system!

Label of a kitefin shark (Dalatias licha) jaw where the ink has faded due to light exposure.

This and other similar issues are covered in a very interesting poster by Amy Davidson, Samantha Alderson & Marilyn fox that can be found here.