[Nhcoll-l] prepping frozen herps

Sun May 1 19:54:23 EDT 2022

Dear all,

Thank you so much for your great and detailed advice on preserving frozen herp specimens, I really appreciate it. I think we will take it on a specimen by specimen basis as to how to preserve the specimen (in spirit or as a skeleton). Thank you especially John for your very detailed and thoughtful explanations of what's going on with frozen specimens and what to look out for. It's an interesting point to note in the records that tissue is from a frozen specimen and so degraded. We tissue frozen specimen salvaged specimens all the time of other taxa (birds and mammals). We don't note it specifically in the database, but how the specimen was collected (salvaged) is noted, so the user should suspect tissue degradation. In general I believe this hasn't been a big problem for many uses requiring only short DNA fragments, although increasingly people are wanting higher quality (and greater quantity) of tissue. Anyway, thank you all so much (as usual) for your awesome feedback!

Cheers,

Tonya

________________________________
From: Nhcoll-l <nhcoll-l-bounces at mailman.yale.edu> on behalf of J Tom Giermakowski <tomas at unm.edu>
Sent: Thursday, 28 April 2022 2:04 AM
Cc: nhcoll-l at mailman.yale.edu <nhcoll-l at mailman.yale.edu>
Subject: Re: [Nhcoll-l] prepping frozen herps

All excellent advice, I’d only add that you should also pay close attention to the defrosting process. Much like with seafood and fresh fish, you want to defrost in such a way that tissues are not frozen deep inside while the outside is already decaying by rotting or worse, drying. This can happen when defrosting in a hot water bath or leaving specimens in a fume hood overnight. We salvaged an old refrigerator for our lab for the very purpose of defrosting specimens.

cheers, Tom

From: Nhcoll-l <nhcoll-l-bounces at mailman.yale.edu> On Behalf Of Greg Pauly
Sent: Wednesday, April 27, 2022 8:31
To: Haff, Tonya (NCMI, Crace) <Tonya.Haff at csiro.au>
Cc: nhcoll-l at mailman.yale.edu
Subject: Re: [Nhcoll-l] prepping frozen herps

  [EXTERNAL]

As others have mentioned, fixing and preserving frozen herps is common practice in herpetological collections. I concur with Andy that you want to be extra diligent with injecting formalin, and also making incisions to allow the formalin adequate access to internal tissues (especially for larger snakes and lizards). As soon as the specimen has started to get a little bit rigid, move it to a formalin bath and keep it in the formalin bath longer than you would for fresh material. Obviously, take tissue samples prior to formalin exposure. With a bit of extra attention during formalin exposure, the resulting specimen will be suitable for all standard research requests (including things like histological examination of gonads). The most challenging thing is to get enough formalin exposure to fully preserve the inside of the GI tract so that dissection for GI parasites isn't complicated by a decomposing gut lining, but I've found this is doable even for larger turtles and snakes as long as you thoroughly inject and move to the formalin bath quickly (I aim for starting at least a partial formalin bath within 8-12 hours).

Greg

On Tue, Apr 26, 2022 at 9:26 PM Haff, Tonya (NCMI, Crace) <Tonya.Haff at csiro.au<mailto:Tonya.Haff at csiro.au>> wrote:

Hello all,

I have read (in John Simmon’s book on herpetological collecting, among other places) that frozen snake and lizard specimens do not make suitable formalin-preserved specimens, and should be instead skeletonised. We have quite a few herp specimens in the freezer that we have been planning on prepping as ‘pickles’ (fixed in formalin and then stored in ETOH), but  I haven’t started yet because of the concern that it may not be worthwhile. I wonder if any of you could weigh in on this and tell me what your experiences have been, and whether or not you would bother preserving these specimens in spirit, or if we should just prep them as skeletons?

Thanks!

Tonya

-------------------------------------------------

Dr. Tonya M. Haff

Collection Manager

Australian National Wildlife Collection

CSIRO

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