Monday, October 29, 2012

Sample sorting

Field season has come and gone, leaving us graduate students with many samples to sort and identify. We also have a few undergraduates helping us out, possibly reconsidering their life choices as they do so.

I collect spiders in my field sites primarily with pitfall traps.

Soapy water breaks the surface tension, drowning anything that falls in :(
After leaving those out for 7 days and collecting oftentimes an obscene amount of arthropods, we store the samples for later sorting.

Next, the spiders need to be sorted out from the rest of the gunk. To reduce the amount of such debris, I recommend using some sort of trap cover while it's in the field.

Spiders, ants, beetles, etc. set aside on the left.
The use of a microscope is necessary for spiders - some are surprisingly tiny!

Camera pic, apologies for the blur.
Those little blobs to the left of the big orange spider? Yup, each a spider. Ants are on the right side of the photo for size reference. The big orange one by the way is Dysdera crocata: The Woodlouse Hunter (my future movie title), an exotic species from Europe which has made its way around much of the world.

Finally, I can actually identify the specimens. It takes time and repeated efforts to learn how to identify a spider to even just family, but I'm now pretty quick at identifying to genus. In the future, I may write a post about how to identify spiders, but for now here are some good links: