[NHCOLL-L:5241] Re: Preserving a dead shark

H.J. Walker hjwalker at ucsd.edu
Tue Feb 1 15:45:29 EST 2011


Agreed; a combination of slitting, and injection into other body areas 
of large specimens would be ideal.  (But on the deck of a rolling ship, 
you just do what you can.)  For some students, fishers, and other folks 
not familiar with formaldehyde in the field, we recommend freezing.  
This allows us to obtain a tissue sample for DNA and to process the fish 
in the lab; and for the most part, these thawed specimens (both 
cartilaginous and bony fishes) are in excellent condition.  One thing 
that should NOT be done is try to fix a frozen specimen in formaldehyde, 
as was mentioned by someone, for reasons previously discussed.
Best,   H.J.

Dirk Neumann wrote:
> Hi Greg,
>
> slitting is preferred especially in (very) large specimens, to allow a 
> sufficient influx of preservative fluids. Even though if you inject 
> highly concentrated formaldehyde solution (up to 37%), you might have 
> problems if the total fluid amount is not sufficient to reach all / 
> the rostralmost organs, i.e.the stomach. Furthermore, the preservative 
> might be degraded from (fatty) body fluids escaping from the - already 
> decomposing - guts.
>
> In many species (especially predators), autolysis of the guts is quite 
> fast. This is not that much an issue with frozen specimens, but with 
> fresh ones, e.g. cichlids of the genus Crenicichla or the herbivorous 
> Steatocranus are notorious for autolysis of their guts within minutes.
>
> Fixation of large herbivorous / detritivorous Cyprinids may cause 
> another problem: because of slow fixation rates of the limited amount 
> of preservative after injection, the enzymatic processes in the guts 
> are not stopped in due time, so that fermentation gases may be an 
> issue (blowing up the specimens like a ballon). But this is again more 
> a problem when fixing fresh specimens rather then frozen ones.
>
> You may be interested in a recent publication on preservation of fresh 
> water fishes in ABCTaxa, which benefited much from the input of Andy 
> Bentley and Simon Moore!
> http://www.abctaxa.be/volumes/volume-8-manual-atbi/chapter-22
>
> You may find preservation routines e.g. for the herps, mammals etc. in 
> separate chapters of this publication.
> http://www.abctaxa.be/volumes/volume-8-manual-atbi/chapter-22
>
> All the best
> Dirk
>
> Am 28.01.2011 14:36, schrieb Watkins-Colwell, Gregory:
>>
>> I agree with Carol.  I formalin-fix a lot of zoo stock and other 
>> things (road kills, etc.) that are frozen prior to me prepping them.  
>> The problem specimens are always either frozen after decomp started, 
>> or from freezers that had electrical issues and thawed a few times.  
>> Freezer burn is also a huge issue, especially if the specimen was 
>> stored in a frost-free freezer.  I’ve had some luck with donors 
>> freezing the specimen in a block of ice.  This at least reduces some 
>> of the freeze-dry effect.
>>
>>  
>>
>> As for injection vs. slitting... does anybody know why slitting is 
>> more common in fish prep than injection?  I have always assumed it’s 
>> because it is faster on a RV to just slit the fish and toss them into 
>> a vat of formalin than it is to stop and inject them individually.  
>> But is there any benefit to slitting vs. injection?  I’ve done both 
>> and personally like the results of injection better.  I feel like I 
>> have more control over where the juice goes.  But maybe I’m missing 
>> something.
>>
>>  
>>
>> Greg
>>
>>  
>>
>>  
>>
>> --------------------------------------
>>
>> Gregory J. Watkins-Colwell
>>
>> Division of Vertebrate Zoology
>>
>> Yale Peabody Museum of Natural History
>>
>> 170 Whitney Avenue, Box 208118
>>
>> New Haven, CT  06520
>>
>> 203/432-3791  or    fax: 203/432-2874
>>
>> -----------------------------------
>>
>> *From:* owner-nhcoll-l at lists.yale.edu 
>> [mailto:owner-nhcoll-l at lists.yale.edu] *On Behalf Of *Carol Spencer
>> *Sent:* Thursday, January 27, 2011 7:27 PM
>> *To:* rrosenblatt at ucsd.edu
>> *Cc:* NHCOLL-L at lists.yale.edu
>> *Subject:* [NHCOLL-L:5219] Re: Preserving a dead shark
>>
>>  
>>
>> Hi all,
>> I prepare many specimens from frozen animals for herps often (from 
>> specimens that people have donated to us). We thaw them completely in 
>> a cold room, then take tissues samples, and THEN prepare in formalin. 
>> You cannot take tissue samples after the specimens has been fixed in 
>> formalin. I have never had a problem with specimens being rotten or 
>> disintegrating before they thaw completely. A bigger issue is the 
>> specimens not turning out as nice as a fresh specimens because of 
>> freezer burn, so for this reason it's best to get it out of the 
>> freezer and prepared as soon as possible.
>>
>> -Carol
>>
>> On Thu, Jan 27, 2011 at 2:36 PM, Richard Rosenblatt 
>> <rrosenblatt at ucsd.edu <mailto:rrosenblatt at ucsd.edu>> wrote:
>>
>> I second (or third) the recommendations of  Dirk and John. It should 
>> be totally unnecessary to inject a small shark. If you thaw it in 
>> formalin the outer tissues will become fixed as it thaws and prevent 
>> further diffusion. One refinement would be to put the specimen in 
>> formalin for 30 minutes or so to let the skin harden before 
>> slitting-keeps the body wall from gaping. All the chemistry as 
>> recommended is simply not needed.
>>
>>
>>
>>
>> DIrk and SImon
>> My concern with thawing the shark prior to preservation is the amount 
>> of tissue damage that occurs during freezing and thawing which is why 
>> I reccomend thawing in fomaldehyde. Your comments on this will be 
>> appreciated.
>> John
>>
>> ----------
>> Sent from the Verizon network using Mobile Email
>>
>> ------Original Message------
>>
>> From: Dirk Neumann <Dirk.Neumann at zsm.mwn.de 
>> <mailto:Dirk.Neumann at zsm.mwn.de>>
>>
>> To: <Couteaufin at aol.com 
>> <mailto:Couteaufin at aol.com>>,<sej139 at yahoo.com <mailto:sej139 at yahoo.com>>
>> Cc: <NHCOLL-L at lists.yale.edu <mailto:NHCOLL-L at lists.yale.edu>>
>> Date: Thu, Jan 27, 8:43 AM +0100
>> Subject: [NHCOLL-L:5211] Re: Preserving a dead shark
>>
>> Hi Steven, Simon,
>>
>> from experiences with preservation of our 200 something Etmopterid
>> sharks I would adjust Simon's procedure as follows:
>>
>> Thaw the shark under cold water (don't use hot water)
>> Pin the fins prior to formalin fixation and try to get the shark in a
>> somehow natural shape (elsewise you will fix the specimen as bended as
>> retrieved from the freezer).
>> Take the tissue sample in advance (immediately after thawing), best take
>> muscular tissue from inside of the body cavity by cutting the abdomen IN
>> FRONT of the anus
>> Cut the body cavity to allow influx of formaldehyde solution into the
>> belly; this works much better then injections and especially allows
>> escape of the oil emerging from the liver which elsewise you will have
>> an awful smelly preservation issue for years (see Simon Moore's comments
>> on this, you may have a pH-issue with breaking fatty acids).
>> Consider to wash the specimen with a bit detergent after recovery from
>> fixation to avoid too much oil in the alcohol.
>> Sharks are rather easy to preserve and not as sensitive as most bony 
>> fishes.
>>
>> Hope this helps
>>
>> All the best
>> Dirk
>>
>>
>> Am 27.01.2011 00:22, schrieb Couteaufin at aol.com 
>> <mailto:Couteaufin at aol.com>:
>>
>>  Hi Steven,
>>  You shark - what you proposed re the formalin sounds fine to me.  Once
>>  fully thawed, inject it with 10% formalin (3.76% formaldehyde) until
>>  it just starts to swell ever-so slightly or the fluid runs out 
>> again.  Make sure that you inject the brain area, the area round the 
>> liver and
>>  the pelvic cavity too.
>>  You can then preserve it (after a few days) in 5% formalin, alcohol
>>  (gradually up a ladder of 20% stages) or whatever preservative seems
>>  easiest.  If you want DNA then don't leave it in formalin for more
>>  than 5 days and transfer to alcohol.  You will get some lipid (as
>>  yellow-brown globules) leaching in time from the liver in particular,
>>  as formalin will only preserve lipid.  Don't worry if the fluid is
>>  still clear but if it turns at all murky or dark brown, check the pH
>>  and change the fluid anyway for fresh.
>>  Have fun and check out the website below, if time permits.!
>>  With all good wishes, Simon
>>
>>  Simon Moore MIScT, FLS, ACR,
>>  Conservator of Natural Sciences,
>>  20 Newbury Street,
>>  Whitchurch RG28 7DN.
>>  www.natural-history-conservation.com 
>> <http://www.natural-history-conservation.com>
>>  <http://www.natural-history-conservation.com/>
>>
>>  http://uk.linkedin.com/in/naturalsciencespecimenconserve
>>  In a message dated 26/01/2011 22:41:20 GMT Standard Time,
>>  sej139 at yahoo.com <mailto:sej139 at yahoo.com> writes:
>>
>>     Hi everyone, sorry to bother the list with something that isn't
>>     really all that
>>     paleo related, but I was wondering if someone could help me out. I
>>     recently got
>>     a roughly 1 foot long baby shark. Since it is so young, I would
>>     like to preserve
>>
>>
>>
>>     it. It is currently frozen in a block of ice until I can figure
>>     out what to do
>>     with it. Since I would like to preserve it, I was wondering what
>>     the best and/or
>>
>>
>>
>>     easiest way to do that might be. I have been leaning toward
>>
>>  >     getting some
>>
>>     formaldehyde or formalin, injecting some into it and preserving it
>>     in a jar with
>>
>>
>>
>>     the rest. If that is best, how much should I inject into it.
>>
>>     Thanks for any help I receive,
>>               ~Steven
>>
>>     ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
>>     Steven E. Jasinski
>>     Paleontological and Research Assistant
>>     State Museum of Pennsylvania
>>
>>
>>     Graduate Studies
>>     Department of Biology
>>     East Tennessee State University
>>
>>
>>     Phone: (717)586-9835
>>
>>
>>
>>
>>
>>
>> --
>> Dirk Neumann
>>
>> Tel: 089 / 8107-111
>> Fax: 089 / 8107-300
>> email: Dirk.Neumann(a)zsm.mwn.de <http://zsm.mwn.de>
>>
>> Postanschrift:
>>
>> Staatliche Naturwissenschaftliche Sammlungen Bayerns
>> Zoologische Staatssammlung München
>> Dirk Neumann, Sektion Ichthyologie / DNA-Labor
>> Münchhausenstr. 21
>> 81247 München
>>
>> Besuchen Sie unsere Sammlung:
>> http://www.zsm.mwn.de/ich/
>>
>> ---------
>>
>> Dirk Neumann
>>
>> Tel: +49-89-8107-111
>> Fax: +49-89-8107-300
>> email: Dirk.Neumann(a)zsm.mwn.de <http://zsm.mwn.de>
>>
>> postal address:
>>
>> Bavarian Natural History Collections
>> The Bavarian State Collection of Zoology
>> Dirk Neumann, Section Ichthyology / DNA-Lab
>> Muenchhausenstr. 21
>> 81247 Munich (Germany)
>>
>> Visit our section at:
>> http://www.zsm.mwn.de/ich/
>>
>>  
>>
>>
>>
>>
>> -- 
>> Carol L. Spencer, Ph.D.
>> Staff Curator of Herpetology & Researcher
>> Museum of Vertebrate Zoology
>> 3101 Valley Life Sciences Building
>> University of California, Berkeley, CA, USA 94720-3160
>> atrox10 at gmail.com <mailto:atrox10 at gmail.com>
>> atrox at berkeley.edu <mailto:atrox at berkeley.edu>
>> TEL: 510-643-5778 /FAX: 510-643-8238
>>
>> http://www.herpnet.org
>> http://mvz.berkeley.edu/
>> http://www.vertnet.org
>>
>
>
> -- 
> Dirk Neumann
>
> Tel: 089 / 8107-111
> Fax: 089 / 8107-300
> email: Dirk.Neumann(a)zsm.mwn.de
>
> Postanschrift:
>
> Staatliche Naturwissenschaftliche Sammlungen Bayerns
> Zoologische Staatssammlung München
> Dirk Neumann, Sektion Ichthyologie / DNA-Labor
> Münchhausenstr. 21
> 81247 München
>
> Besuchen Sie unsere Sammlung:
> http://www.zsm.mwn.de/ich/
>
> ---------
>
> Dirk Neumann
>
> Tel: +49-89-8107-111
> Fax: +49-89-8107-300
> email: Dirk.Neumann(a)zsm.mwn.de
>
> postal address:
>
> Bavarian Natural History Collections
> The Bavarian State Collection of Zoology
> Dirk Neumann, Section Ichthyology / DNA-Lab
> Muenchhausenstr. 21
> 81247 Munich (Germany)
>
> Visit our section at:
> http://www.zsm.mwn.de/ich/ 
>   

-- 
 H.J. Walker, Jr.
 Scripps Institution of Oceanography
 University of California, San Diego  0208
 La Jolla, CA   92093-0208
 USA
 hjwalker at ucsd.edu
 phone:858-534-2199   fax:858-534-5306

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