Fish Preservation...

[davo]

Ok so finally got around to finding something suitable to put what I want to preserve in.

I have a few questions though.

When reading... http://research.amnh.org/ichthyology/congo/other05.html
it mentions a "10%" formalin solution is what is normal, but isn't enough for fish in the congo: so instead of 1 part full strength formalin to 9 part water they use 1 part to 5 parts water. Even though the fish I want to do it with is from SA, will it matter if I do say a little more than 1:9? As in effect the specimen.

I've also read that if your preserving so that DNA analysis work is possible down the line, that 90%+ ethanol is better. Is there any other difference, because I might do this instead, and change the solution after a week or so I am told.

Also I have heard that for large specimens you need to make a slit in the belly so that the liquid can permeate the inner organs properly. Well how big is large... This is only a 4-5" specimen TL so wouldn't think necessary, but thought I should check?

I think that's it, thanks a lot.

 

[Vicious_Fish]

The only fish I ever preserved were a Chinese Algae Eater and a Baby albino Oscar. I just used 100% rubbing alcohol. I did this as a kid but I know I had them in that jar for many years and they didn't change much in that solution. Don't know what ever happened to that jar.

 

[davo]

hmm cheers mate. Shame you didn't keep it! If you ever find it post a pic be interested to see it now.

 

[Druu]

Rubbing alcohol is usually 70% isopropyl. When I interned at the museum we had large fish in jars that were not slit in the belly. I think you should temporarily treat it with formulin then permanently house it in alcohol.

 

[tunerX]

People think I am weird for pickling worms in garlic and baby vitamins.

 

[beblondie]

Preservation
we use 70% alcohol for preservation (or at least maintenance of perservation) of our specimens...this is diluted from the 95% stuff we keep on hand in the lab. the actual preservation/fixation, however, is done with formaldehyde. if the fish is larger than just a few inches then i cut the belly so the chemical can enter into the insides of the fish and preserve everything. the fish stays in the form. solution for a couple days. if its a gar or bichir, a fish that has rigid bony scales, then i take the fish out after 2-3 days and just let it air dry. the fish is now dry preserved.

if im doing a standard preservation i take the fish out after 2-3 days and let it sit in a container of water to soak out the formalin. after a day in the water the fish is removed and placed into a container of 70% alcohol for long-term preservation.
as far as using other alcohol, i think as long as its relatively pure and the proof is about 140 you should be ok...in theory