During the summer of 2024 I observed 15 aquatic mites as shown at this link.
I subsequently sent the mites for identification to Canada’s National Identification which is part of the Canadian National Collection of Insects, Arachnids and Nematodes (CNC) operated by Agriculture & Agri-Food Canada. The mites were sent as complete organisms in 1 dram vials of 70% isopropanol.
They were examined for identification purposes by well-known Canadian acarologist Ian M. Smith. He was able to identify them as to genus but only one to species. The identification records provided for the mites read, “Microscope slide preparation necessary for further identification.”
Can anyone explain exactly what is involved in preparing microscope slides that can be used to identify aquatic mite specimens at the species level? I shoot macro with a dSLR camera and have almost zero knowledge of microscopy. If I were to collect more aquatic mites this summer, is slide preparation something I could do and then send the slides to NIS instead of sending the entire organism?
It often involves dissecting off the limbs, especially the palps, so you can get a high-powered microscope on them to see tiny hairs. The main body would usually be cleared to make it transparent so you can see the precise positions of hairs and bristles. You would end up with a permanent microscope slide of the specimen for future reference. I haven’t done it and if you haven’t done any microscopy before, it would be jumping in at the deep end. You would need some dissecting tools and a range of chemicals for the specimen preparation and preservation, not to mention a microscope, maybe two. I’ll have a look for a paper that describes the process better than I have.
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I don’t have any papers describing the production of microscope slides of water mites. This
https://www.field-studies-council.org/resources/field-studies-journal/a-key-to-the-water-mites-hydracarina-of-the-flatford-area/
covers the previous stage of preserving the whole animal.
When I have needed to look at e.g. a limb under high power, I have dissected it off with fine entomological pins on a cavity microscope slide in 70% Industrial Methylated Spirit (the preservative I generally use). I try to photograph it down the microscope, then just stick the mite and its severed limb back in the tube of alcohol hoping I won’t need to look at it again, but it is all in there if the need arises. I suspect I.M. Smith wouldn’t approve. Industrial Methylated Spirit is mainly ethanol but with enough methanol added to make it toxic. Pure ethanol is better if you might want to take a DNA sample but will dehydrate the specimen and make it very brittle and is harder to get hold of.
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Thank you for your for both of your helpful replies. I was guessing that it might me more than I could manage to properly mount my specimens on slides but you’ve confirmed that.
Thank you also for the link to the 1961 paper by C. L. Hopkins that provides keys to mites of the Flatford area in Suffolk, England. Very interesting.
I’d like to IDt my mite specimens to the species level but I now see that doing that morphologically is way beyond my abilities. Perhaps I’ll explore the COI barcode route as a possibility.