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Specimen preservation?

4 replies to this topic

#1 Betta132

  • NANFA Guest
  • San Gabriel drainage area

Posted 20 April 2016 - 08:57 PM

I'm in the habit of collecting any freshly dead fish I happen to find, but so far my collection is mostly just in jars of rubbing alcohol, which doesn't seem to work very well. The specimens tend to dehydrate, distorting their shape somewhat, and they usually lose their color to some degree. Up until now, all I've had on hand is rubbing alcohol, but I have denatured ethanol and technical-grade formaldehyde available now. 

So does anyone have any good guides for what I should do? I'd like to preserve shape and color as much as possible, obviously. I have some specimen-grade jars and some big syringes, too. 

#2 Evan P

Evan P
  • NANFA Guest
  • Knoxville, TN

Posted 20 April 2016 - 10:13 PM

For morphology, go for formalin. For DNA, use ethanol.

3,000-4,000 Gallon Pond Full of all sorts of spawning fishes! http://forum.nanfa.org/index.php/topic/13811-3560-gallon-native-fish-pond/page-3 

#3 gerald

  • Global Moderator
  • Wake Forest, North Carolina

Posted 21 April 2016 - 09:51 AM

The only thing that will preserve color is a camera.  Color will last longer in formalin than in ethanol, but still not too long.

Gerald Pottern
Hangin' on the Neuse
"Taxonomy is the diaper used to organize the mess of evolution into discrete packages" - M.Sandel

#4 zooxanthellae

  • NANFA Member
  • North Carolina

Posted 21 April 2016 - 10:07 AM

If you are looking for long term preservation, neither alcohol nor formalin alone will suffice. One widely accepted method is to fix the fish in formalin, and then place it in alcohol for long term storage. Check out this page for a description :



With that said, as a kid I would preserve freshly dead aquarium fishes in rubbing alcohol, and they are still well preserved 15 years later! 

#5 Betta132

  • NANFA Guest
  • San Gabriel drainage area

Posted 22 April 2016 - 02:10 AM

I've definitely seen the color leach out of just about all of my specimens so far, but I do have a few shiners still living up to their name (I suspect because their color comes from reflectiveness rather than pigment) and a trout that's held its color since December. 

Is freeze-drying an option? We do have a deep freeze, but it's mostly used for food, so I wouldn't be able to do anything that would stink it up. 

Would a good method perhaps be to photograph the specimen as soon as possible, preserve it, and keep the photo with its records? There's a very good camera on my phone, and at worst, I could probably put it in alcohol for a few hours and photograph it at home. Most of the color sticks around for at least a couple hours. 

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