Proper spider specimen preservation?

freeze drying

While isopropyl is the standard, freeze drying can be used if you have patience or good equiptment. I pin insect nymphs and spiders and place them with rice (acting as a dessicant) in a good, sealable jar. I then fill the jar with refrigerated air, loosely seal it and stick it in an oven on low (heats the dry air, which can escape the jar as it expands without letting moister air in). Then, fully seal the jar and put it in a freezer (slowly, don't shatter it). Viola, a (slightly) low pressure freezer. With this procedure, it takes a couple months to dry a Black Widow. A commercial freeze dryer is faster. It is slow, but preserves color and hairs that alcohol tends to destroy.

… Austin Shepherd, 6 September, 2012 - 5:25pm

Spiders are preserved in alcohol

either ethyl or isopropyl. The unfortunate side effect is that colors will fade or change, but there is not really a way around that as far as I'm aware.

… Brad Barnd, 4 September, 2012 - 3:52pm

I agree that 70% isopropanol works fine, and that discoloration and some shrinking of specimens is unavoidable. Other people prefer 70% ethanol, but one arachnologist (Robert Holmberg) warned me against using denatured ethyl alcohol (ethanol) because some of the chemicals that are added to make it undrinkable might be harmful to specimens. So, if you're going to use ethanol, make sure it is not denatured.

I have close to 1000 preserved spiders in my collection, all in 70% isopropanol, and I find it works well. It does not preserve colors very well, but preserved specimens are identified or examined mainly for their structures and not for color. My specimens go back as far as 2004, and I like the fact that the legs and chelicerae remain flexible.

For larger specimens I replace the alcohol once after the first couple of weeks because enough body fluids from these larger spiders can leak out to dilute it.

Just as important as the preservative is a label with collection data on it: date collected, location (GPS coordinates are good to have), name of the collector, collecting method, habitat, etc. Here is detailed information on collecting spiders that includes info on perservatives and labeling: http://www.burkemuseum.org/pub/SpiderCuration.pdf

A specimen without a proper label is useless!

… John Sloan, 4 September, 2012 - 8:49pm