Preserving your dead fish

[toehead11183]

Does anyone keep their deads?
If so, How do you preserve them?
I've heard putting fish in high proof alcohol works but what about long term?
I've had a madtom for years and he just died. I got it in the freezer and i want to keep him.
How should i go about preserving him?

[racoll]

Alcohol will preserve the fish, but will also dehydrate it, make it brittle, and remove much of the colour. It won't look great, or be much use for study.

You will need access to formalin to fix the fish in (kill bacteria and prevent further biological degradation).

Formalin is a pretty nasty substance, and I don't know if you can get access to it in Tennessee.

After the formalin fixation though, you can store it long term in 70% alcohol or methylated spirit.

If you can't get formalin, why not donate the madtom to your local natural history museum that houses a fish collection?

They will look after it on your behalf for posterity, scientists of the future will be able to study it, and your name will be immortalised as a benefactor.

[Birger]

I've had a madtom for years and he just died.

If you do not mind me asking...how many years was it, as I have read a couple different opinions on lifespan of these...and do you know which species of madtom

[worton[pl]]

Hey,

few photos of dried fish (they usually die during shipping or just after shipping):

http://www.suephoto.com/index.php/galeria/index/5/361

http://www.suephoto.com/index.php/galeria/index/5/364

I'm not sure however how long they will last just after drying.

Regards.

[Carp37]

As Racoll suggests, I used to use formalin for keeping fish preserved when I'd got access to it via university. If the container lid is not tight-fitting then it will evaporate over time. Absolute alcohol might also work but I think it's even more prone to evaporation.

[toehead11183]

It was a tadpole madtom. I got 2 at 1/2" with some ghost shrimp at the LFS i worked at. I have had both for a little more than 3 years. I orriginally gave them to my african cichlids as feeders but a year latter when i went to remove the fish durring a tank upgrade, i found them hiding under the rocks. I have kept them with african cichlids, for 2.5 of the years and now i have them in an in-tank refugium in my 180. the other is doing just fine.

[Chrysichthys]

year latter when i went to remove the fish durring a tank upgrade, i found them hiding under the rocks

See? See? I'm not the ONLY ONE who finds catfish in his tank which he didn't know were there!

One option might be to preserve and mount the skeleton. It would look more attractive. I think that it is done by using a solution of sodium hydroxide (caustic soda) to dissolve away the flesh. You need to be careful with it, safety-wise.

[worton[pl]]

Hey,

second option may be using fly's larvaes or/and ants . They should be able to eat flesh and leave bones.

[Mike_Noren]

The best is formalin fixation (5% formalin solution for a couple of days), followed by transfer to 20% alcohol for a day, then 50%, then finally 70%, which is what you should store it in.
Raising the alcohol concentration slowly means that the fish will keep its shape better.

Formalin has poor penetration into tissues, so for large fish you'd need to inject formalin or make a hole in the body wall, but that wont be a problem with a little madtom. When you put it in the formalin, make sure it assumes a good posture, ie not bent double or against the wall of the jar, because the way it looks in the formalin is the way it'll look forever. It's actually pretty hard to make good-looking formalin preservations of fish.

So how long is forever? No-one really knows; the oldest formalin-fixed fish, which are several hundred years old, still keep their shape just fine. Not their color, although black pigmentation stays on longer than red or blue.

Alcohol fixation will preserve the fish, but the fish will shrivel a bit, and will lose its color. On the other hand alcohol preservation, unlike formalin, also preserves the DNA.

Freeze-drying: I've not done this with fish, but it worked with a 10" starfish so maybe also with fish. I froze the starfish in fresh water, placed it in a plastic bag with silica gel (can be bought as "crystal kitty litter" and similar), put the bag in the freezer, replaced the silica gel every few weeks, and after several months had a perfectly preserved, shape and (most of the) color, starfish. Also preserves DNA.

And yes, Natural History museums will accept and preserve your fish for posterity if you give it to them. If you know where and when the fish was caught, that increases its value to them.

[Bas Pels]

Even after keeping the fish for 20 years in an aquarium?

[Mike_Noren]

Yes.

I don't know if it's different in smaller museums where space may be at a premium, but we'll take anything. And I mean that literally.
You never know what material might prove valuable in the future. Who'd have guessed, ten years ago, that once-common species like cod, eel and pollack would suddenly be endangered (and, in the case of eel, even on the CITES list)?

For aquarium fish it doesn't really matter how long they've been in the aquarium, but that they can be identified to species is important, and if there's some sort of capture locality that greatly increases the value of the specimen.

[judiefish]

mike . noren.... uno u said abou freeze drying would it work on gold fish ?
and where do you get the gell? is it the stuff u get i bags in the satchets wen u buy em? how mutch would i need for a gold fish? do u use a normal freezer

[racoll]

uno u said abou freeze drying would it work on gold fish ?

In theory. Why don't you try?

where do you get the gell?

How about http://www.magichem.co.uk/. They are based in south Wales.

Now, of course, I don't know any more about procuring dessication gels than anyone else, I just typed it into Google

[L number Banana]

You can buy dessicant gels and grains of different size at craft stores. We use it to preserve larger flowers.