Tarantula Preservation/Fixation

[charm271]

There seems to be only a small amount of information on Tarantula preservation/fixation. Most display specimens to me look like someone just left the tarantula out in the sun and/or flatten it with a book. Some people don't bother with fixation of the specimen and proceed with evisceration and stuffing with cotton-wool which is better in my mind than just drying it flat. However, I believe all specimens should be first placed in a preserving liquid before mounting/display, whether one chooses to eviscerate and stuff their specimen or not.

The liquids available to the common household are acetone (nail polish remover), ethanol (drinking alcohol), isopropyl alcohol (rubbing alcohol), acetic acid (vinegar), glycerol, and sodium chloride (table salt). Although allot of preservation formulas include formalin/formaldehyde in some amount we are going to assume most people do not have access to it.

From my reading the primary base for most formulas is ethanol. Acetone and isopropyl alcohol are used less frequently because they both can cause discoloring and excessive hardening (causing the specimen to be brittle). If ethanol is not available isopropyl alcohol would be the next choice. You would want 70 - 90 % of your solution to be ethanol (the strongest clear spirits available to you). Assuming you are only obtain a 40% alcohol then it should be 80 - 90% of your solution. If you can obtain a stronger alcohol then it should be 70 - 80%.

Acetic acid and glycerol are agents used to counter the hardening of the alcohol. The amount of acetic acid and/or glycerol will depend on the amount and strength of the alcohol used. Amounts of acetic acid in the formulas seems to vary from 5% to 25%. Glycerol is sometimes included in formulas but it never more than 5% (i.e. several drops). A few formulas suggest the use of salt (1% or less or a "pinch"), I don't think it is necessary but it is mentioned.

If anyone else has suggestions, ideas, or formulas different than this please comment. If you think there are other methods fixation that are better or that fixation is not necessary please comment also.

 

[PrimalTaunt]

When some select tarantulas of mine die I plan on casting them in resin. See this thread for info on how.

 

[charm271]

When some select tarantulas of mine die I plan on casting them in resin. See this thread for info on how.

I wonder if fixation would help the people wanting to do resin casting instead of "dry" display. I do not know if fixation would help the specimen resist the discoloration caused by some resins. I think it would help prevent problems with the abdomen during casting.

---------- Post added 08-05-2012 at 01:04 AM ----------

Here is a quick link to a rubber product for preserving a tarantula. The produce does not generate heat so discoloration should not happen to the specimen.

http://www.smooth-on.com/gallery.php?galleryid=327

 

[Tarac]

Acetone was not on the list, this is an ideal solvent for preserving inverts because it simultaneously fixes, dries and defats the specimen. It therefor helps preserve pigment based colors.

 

[Scoolman]

The liquids available to the common household are acetone (nail polish remover), ethanol (drinking alcohol), isopropyl alcohol (rubbing alcohol), acetic acid (vinegar), glycerol, and sodium chloride (table salt). Although allot of preservation formulas include formalin/formaldehyde in some amount we are going to assume most people do not have access to it.

From my reading the primary base for most formulas is ethanol. Acetone and isopropyl alcohol are used less frequently because they both can cause discoloring and excessive hardening (causing the specimen to be brittle). If ethanol is not available isopropyl alcohol would be the next choice. You would want 70 - 90 % of your solution to be ethanol (the strongest clear spirits available to you). Assuming you are only obtain a 40% alcohol then it should be 80 - 90% of your solution. If you can obtain a stronger alcohol then it should be 70 - 80%.

Acetone was not on the list, this is an ideal solvent for preserving inverts because it simultaneously fixes, dries and defats the specimen. It therefor helps preserve pigment based colors.

It was mentioned.

I have used straight 90% isopropyl for a couple of mine.

Charm271 would please elaborate on the process from beginning to end.

 

[Tarac]

Oops, why I should not read on my phone

Acetone is regulalry used with inverts because it fixes non-refractory colors and does not disrupt the morphology, almost the only solvent used for Odonata for example. Not sure why it is said to discolor. It does opaque eyes but it is pretty good for everything else and is used for cleaning specimens from beetles to butterflies to individuala cells because of these properties.

Formalin can be purchased from fish supply stores. You can buy pond sized doses which would be plenty for preserving a T.

 

[charm271]

I would like to get into preserving tarantulas but have no practical experience. The information posted is based from my readings and my experience in a medical/human histology lab. For those using acetone and/or isopropyl alcohol does it cause discoloration in brightly colored species? Are the specimens once removed from the liquid preservation excessively hard? When you preserved your taranrula did you injection the T or do you simply put the T in the liquid? Do you keep your specimens in the preservation liquid or do you take them out for some form of mounting/display?

 

[Tarac]

I would like to get into preserving tarantulas but have no practical experience. The information posted is based from my readings and my experience in a medical/human histology lab. For those using acetone and/or isopropyl alcohol does it cause discoloration in brightly colored species? Are the specimens once removed from the liquid preservation excessively hard? When you preserved your taranrula did you injection the T or do you simply put the T in the liquid? Do you keep your specimens in the preservation liquid or do you take them out for some form of mounting/display?

Isopropyl will fade the specimen's pigment based colors more than acetone, which is used intentionally to fix proteins (pigments included), permeabilize and degrease your specimen. Acetone does indeed "dry" the specimen so it will be hard and not easily repositioned after acetone treatment. In general you are going to want to pin out the specimen so it is positioned as you would like it and then submerge it in an acetone bath (preferably acetone that is freezer-chilled, put it in the container and then back in the freezer for a day or two to ensure thorough de-greasing and better pigment fixation).

If you need to tweek something in terms of positioning you can inject the joints around the area with some household ammonia. Most ammonia is now sold with a surfactant mixed in which will help it permeate the joint BUT be careful with this step because that will also disrupt the morphology a bit, especially in terms of making the setae look "wet" if too much excess pools on them. Also note that it might not be worth even using the acetone for anything other than de-greasing and cleaning in the case of a tarantula because the majority of the color on them is refraction based anyway. Those kinds of colors will last one way or the other so long as you don't bother the setae much.

My experience is also from a medical lab (proteomics/cell biology) but also comes from years and years of collecting insects, more years than I have been keeping tarantulas. This is standard procedure for preserving many orders and for cleaning up specimens that have darkened over the years from slow leaking of fat that breaks down and exudes over time. It's about the only way that people work with dragonflies and relatives as so many of the colors are pigment based and are lost almost immediately after the dragonfly is killed. You can dip a moth right into the acetone and it will come out looking brand new without any disruption to its form. You do always want to secure your specimen in position as it is possible for it to become just flexible enough while submerged that it will move out of position.

There are other solvents that can be used but most have drawbacks and are not as good at preserving the majority of colors. There are a few colors that preserve better with other solvents though, pruinose species for example. But this should not really be an issue with tarantulas, as mentioned.

Here is an example of a de-greasing setup being used on an Arctia sp.:

http://nitro.biosci.arizona.edu/zEEB/butterflies/relax.html

And another from a hobbyist using an Ornithoptera sp.:

http://community-2.webtv.net/guestsbook/CleaningDegreasing/

I have not mounted a tarantula myself but friends of mine who have always use the eviscerate/stuff/suture closed method for keeping the opisthosoma nice and plump looking.

 

[zonbonzovi]

Just one more question: are there any preferred materials to pin the creature to that won't discolor/break down while in the acetone bath?

I met a guy last year at a bugfest up here that had exquisite pinnings(his spiders were unbelievable fantastic) of all kinds of insects but all lacked the bulk of a tarantula. He could get away with pinning on styro and inverting them so only the creature & pins would be submerged in the acetone. I don't see gravity allowing this, esp. for a floppy opisthosoma. I would like to try this right side up, if possible.

 

[charm271]

Just one more question: are there any preferred materials to pin the creature to that won't discolor/break down while in the acetone bath?

I met a guy last year at a bugfest up here that had exquisite pinnings(his spiders were unbelievable fantastic) of all kinds of insects but all lacked the bulk of a tarantula. He could get away with pinning on styro and inverting them so only the creature & pins would be submerged in the acetone. I don't see gravity allowing this, esp. for a floppy opisthosoma. I would like to try this right side up, if possible.

This may sound dumb but why can you not just fill the container to the brim put the Tarantula into it and place the lid on? The tarantula should be mostly submerged and the container can be inverted every now and again to submerge other areas. If the abdomen stays floppy is it not possible to use crazy glue or other support to hold the abdomen in the place?

 

[Tarac]

You can't use styrofoam at all, even if it isn't touching the acetone, because it is very volatile and will still melt the foam in a closed container. If it isn't completely sealed you won't have any acetone in there for very long.

I use balsa wood and regular insect pins. I use the nylon head type, they don't melt. You can use plain sewing needles too, just smash the little plastic head off. Anything all metal is fine. You can do it right side up as long as you make sure the lid doesn't hit the positioning pins when you are closing it. A solution is to put longer nails/screws in the corners of your pinning block so that when you close the container the lid pushes on those (and not the pins holding the specimen in place), which will both allow you to pin with the specimen facing up without worrying about it floating/bumping the lid and thereby distorting or coming out of position and also force the block and specimen down into the acetone further as the lid pushes on the nails in the corner.

I do this mostly for beetles and very heavy bodied moths that tend to grease up quickly because of high fat content but also for damselflies/dragonflies. They are especially challenging because you have to work really really fast, pretty much with a live but unconscious specimen. They turn brown/black almost immediately after death if you don't acetone treat them right away, so many proteases in a dead organism cutting up those pigments.

I have not tried myself, but have wondered if you could inflate the opisthosoma with latex or silicone injected into it so it would remain nice and plump. Maybe even a small balloon type of idea, in the way that papier-mache forms are made. If you do the eviscerating/stuffing technique, be sure that what you choose for the filler is acetone safe in that it won't melt or be eaten away.

 

[zonbonzovi]

Yeah, styro was a slurried mess.

Ah, balsa! Soft enough to pin into and kind of moisture resistant. Most of my specimens are frozen and trial runs with roaches don't seem to have any deleterious effects on the exoskeleton from excessive moisture in the expired creatures.

Thanks!

 

[Tarac]

Yeah, styro was a slurried mess.

Ah, balsa! Soft enough to pin into and kind of moisture resistant. Most of my specimens are frozen and trial runs with roaches don't seem to have any deleterious effects on the exoskeleton from excessive moisture in the expired creatures.

Thanks!

No problem at all. The freezer is the optimal way to keep them for the most part, that is how I store all my specimens that are waiting to mounted. The exception again are those specimens that you want to preserve protein based pigments on, in which case you have to fix almost immediately. The freeze/thaw cycle on those types will sheer the pigments and also the slow warming gives ample opportunity for protease cleavage so you will end up with blackish/brownish specimen if you don't treat them right away. For dragonflies, for example (I use them as an example because they are notoriously difficult to preserve well), a lot of people kill them by putting them in an envelope and submerging it in acetone so they are both killed and fixed at once. Scientific specimens of these are usually mounted with wings folded on their sides anyway because much of the ID characters are found on the sides of the thorax. But even if you want to spread them out like a moth they kill them this way and then reposition later on using something that is injected into the joints like the previously mentioned ammonia.

Your application will dictate what the best approach is. I think with tarantulas won't need much special treatment, just care to keep the hairs in place and that type of thing. Acetone is really convenient anyway because it de-greases and dries at once but it's probably not necessary for such hairy creatures other than the de-fatting properties which you may have to use eventually anyway due to the scale of most tarantulas. Generally bigger bugs will need this treatment eventually or they will get tinted with orange-yellow-brownish and the hairs will become greasy and wet looking, which if allowed to become too extreme will not be reversible even with acetone treatment. They may become less wet looking but the hairs will stay matted down.

Best of luck with your specimens, would love to see some photos of how they turn out.