Unidentified Spider Pics - Picture Quality?

[Yashca]

I was recently gifted an old microscope from a friend, and have been experimenting with attaching a camera to the top to take pictures of various beasties through it.

After talking with Jason Green on another thread, it seems my microscope isn't really suitable for the detailed study that would be required to identify various invertebrate species.

Nevertheless, using all my ingenuity and cunning, I took a few close up pictures of a dead spider.

Front leg


Spider's eyes


Abdomen


And the best my actual camera can do:


I found the spider, deceased, in a bird hide at North Cave Wetlands, East Yorkshire. I'm guessing that my hope of setting up the camera and microscope to allow me to photograph invertebrates for identification might not work out, what with it being the wrong type of microscope, but hey, you never know.

I had a quick perusal of Jason's 'London Invertebrates' website, and my, admittedly uninformed, guess would be some sort of Zygiella species, as it shows similarities to Zygiella X-notata shown on that website.

Thanks everyone,

Yashca.

[Jason Green]

Afternoon Yashca,

Originally Posted by Yashca

After talking with Jason Green on another thread, it seems my microscope isn't really suitable for the detailed study that would be required to identify various invertebrate species.

I think I badly-worded that! Compound microscopes like yours are very high in magnification - but due to the small working area between the objective lens and the top of the specimen plate you don't get the work area required for rotating an insect. Dissecting/stereo-microscopes have often around 100mm to work in, attainable due to lower magnification and subsequent depth of field.

Some insects need pretty high magnification such as the genitalia of certain flies and moths - more than is typically provided by a dissecting model. Therefor, you need to remove the genitals under the dissecting microscope and prepare a flat microscope slide for viewing it at higher magnification. You view this under the compound microscope at, say, x60. Some hoverflies can only be confirmed under the microscope by viewing the wing's degree of microtrichae. One such Syrphid is Syrphus vitripennis, which has only 50% in the basal cells.

As for your spider, to me it looks a little Theridiidae/Linyphiidae-like, but I'm not really qualified to comment on these. I can't see the palps to sex it; males have bulbous-tipped, punchbag-like palps, girls' are slim all the way down. A good view of the male's palps are needed for species-level IDs, and a view of the girl's epigyne (found under the abdomen) in her case. A good book on these is 'Spiders of Britain and Northern Europe' by Michael J. Roberts, but I don't have it.

[Yashca]

Just took a quick picture of the palps. From the look of it, I'd say these looked slim all the way down, thus a female, thus a view of the epigyne would be needed. I'm going to go try and found out what and where that is, and see if I can find it. How is that word pronounced, by the way?

Is there anyone in particular on WAB who is a wiz with spiders?



**EDIT**

Do these pictures depict the epigyne?

[Jason Green]

Hi Yash,

Two members - Wild About Britain - View Profile: No.9 Spider, and Venger - Wild About Britain - View Profile: Venger are regular spider experts. We also have others who pop-on too such as Meta menardi and a guy from the Netherlands - I forget his username!

Yes, that's a lady and a good shot of the epigyne. Careful though, an immature male's can appear like this. I can't help with this ID, but one of the above will. As for keeping the specimen if you choose, a vial of 70-90% alcohol would be needed (it has a proper name, and possession of the liquid requires an I think easily-obtained licence from Customs and Excise...).

They spider people, as said, can advise better on all this!