Pholcus phalangioides (I think!)

Images of undisturbed subjects in their natural environment. All subject types.

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davidholmes
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Joined: Mon Aug 08, 2016 1:30 am
Location: Bristol UK

Pholcus phalangioides (I think!)

Post by davidholmes »

We see lots of these especially in autumn. This one was hiding in a saucepan.
Does anyone know what the white tissue on the abdomen is?



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Ken Ramos
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Post by Ken Ramos »

Interesting images, a fungus maybe? :smt017

davidholmes
Posts: 33
Joined: Mon Aug 08, 2016 1:30 am
Location: Bristol UK

Post by davidholmes »

I don't think it is a fungus as I have looked at several of these spiders and they all seemed to have white patches in the same place. I was thinking it was more like glandular tissue but my knowledge of spider anatomy and certainly endocrinology is a bit limited. A brief internet search shows some images with similar features but I have not found any description of gross anatomy other than the most basic.

Ken Ramos
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Joined: Thu Jul 27, 2006 2:12 pm
Location: lat=35.4005&lon=-81.9841

Post by Ken Ramos »

What led me to think of a fungus was that in the last two frames of this thread, the white patch seems to favor one of the spiders eyes also but looks more like a silk patch than a fungus...maybe. Still dunno? I read through several Google search references but found nothing more than discriptive references to the white patches as nothing more than abdominal markings. :smt017

MarkSturtevant
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The white structure

Post by MarkSturtevant »

The white structure should be paired, and if so then they are covers to what are called 'book lungs'. These are respiratory structures that spiders and other chelicerates use for breathing. Internally, book lungs look a lot like gills, and that makes sense since the ancestors to spiders were probably aquatic.
A similar picture is here:
https://www.amentsoc.org/insects/glossa ... /book-lung
Mark Sturtevant
Dept. of Still Waters

MarkSturtevant
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Really good!

Post by MarkSturtevant »

I wanted to add that these are really good pictures. We have a similar species, and I have tried to get decent pictures and failed utterly. My problem was trying to get a lot of their legs in focus, along with the body, and that is really not possible. Your approach is far better.
This inspires me to try again. I will need to use subjects like this to get me thru the long winter... :)
Mark Sturtevant
Dept. of Still Waters

davidholmes
Posts: 33
Joined: Mon Aug 08, 2016 1:30 am
Location: Bristol UK

Post by davidholmes »

Thanks for this information - that explains it and the site looks like a useful source for further information.
Thanks also for your kind comments on the images.

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