[Nhcoll-l] Preservation issues

[John E Simmons]

I suspected it might be a DPR. The longer the specimen has been dead, the
more difficult it is to fix, both due to the slower penetration of the
fixative and the breakdown of the tissue matrix, which begins with cell
death. When collecting DOR specimens, it is best to fix them as quickly as
possible. If the specimens have to be frozen (which causes osmotic damage
to the cells, as Dirk mentioned) I recommend thawing them in a 10% buffered
formalin solution and injecting them as they thaw (but if you want tissues,
remove those before the specimen is in contact with formaldehyde). You may
not ever be able to get this specimen to harden up as much as a fresh
specimen would due to previous tissues breakdown (it depends largely on how
long the interval was between death and fixation, and the temperature it
was exposed to).

John E. Simmons
Writer and Museum Consultant
Museologica
*and*
Associate Curator of Collections
Earth and Mineral Science Museum & Art Gallery
Penn State University
*and*
Investigador Asociado, Departamento de Ornitologia
Museo de Historia Natural, Universidad Nacional Mayor de San Marcos, Lima


On Thu, Jun 22, 2023 at 11:28 AM Marshall Boyd <marshallboyd1989 at gmail.com>
wrote:

> Thanks everyone. The snake is a Black Racer snake, about 3-4 feet long. We
> injected using 10% buffered Formalin following John Simmons guide (love
> your book by the way) and after injection partially submerged but with
> formalin soaked paper towels for 4 days (over the weekend). The specimen
> still seems much more malleable and floppy than previous specimens. It was
> a DOR with several sections rather crunched from a car but was tissued and
> fixed June 8 (within 2 days of discovery) and moved to 20% EtOH June 13 but
> was not moved to 40% EtOH upon discovery it wasn’t fixed as much as we were
> hoping June 16. _______________________________________________
> Nhcoll-l mailing list
> Nhcoll-l at mailman.yale.edu
> https://mailman.yale.edu/mailman/listinfo/nhcoll-l
>
> _______________________________________________
> NHCOLL-L is brought to you by the Society for the Preservation of
> Natural History Collections (SPNHC), an international society whose
> mission is to improve the preservation, conservation and management of
> natural history collections to ensure their continuing value to
> society. See http://www.spnhc.org for membership information.
> Advertising on NH-COLL-L is inappropriate.
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://mailman.yale.edu/pipermail/nhcoll-l/attachments/20230622/9300d639/attachment.html>