Tetragnathid

The Spider Faery

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Hello, fellow Canadians or anyone else that might know..I'm especially wondering if you can help, Jsloan because I know you've referenced from the Checklist Of Spiders Of Canada And Alaska before.

Anyways, I thought I had found a Pholcus phalangioides spiderling but now I'm leaning towards IDing it as a Tetragnathid. It sits diagonally in its web with its long front legs outstretched in front of it in a classic tetragnathid pose. It almost looks like a mosquito. It's legs are long but they aren't as spindly as a cellar spider's, imo.

Sorry I don't have a pic, but does anyone know what species of Tetragnathid is common to Ontario? I'm trying to decide how to ID this spiderling, thanks.
 

jsloan

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Whew! You could have picked an easier group to work with. :)

There are 12 species of Tetragnatha (Tetragnathidae) in Ontario, but they are almost impossible to tell apart without examining the palp or epigyne. Even then it's very difficult. The male ID often hinges on the shape of the tip of the embolus, which is very small, and for the females you usually have to dissect the epigyne and look at it from the inside out. You need a good microscope and the right species keys to do it. The only species in Ontario that you could easily identify just by general appearance would be T. viridis, which is bright green.

It's not hard to ID Tetragnatha to genus, though. They all build orb webs, often horizontal and usually with threadless hubs (as opposed to the tangled webs of Pholcus sp.). They sit in their webs much the way yours does. Also, they tend to have large or oversized chelicerae. Unfortunately, you can't determine the species from the configuration of the chelicerae, or from the arrangement of the eyes (though you can place them into certain groups of species by the eyes).

Here are pictures of some species that you can compare your spider to: http://bugguide.net/node/view/1997/bgpage
 
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The Spider Faery

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ha!

it looks like an Oxyopdiae lynx spider and a normal tetra had a baby!


http://www.google.com/search?q=tetr...t=mode&cd=2&ved=0CAcQ_AUoAQ&biw=1600&bih=1067

Haha, it does. Unfortunately mine's not green, but adorable nonetheless.

It's only 10 mm's with its legs outstretched, so it's small but now that you mention the oversized chelicerae, I can actually see some, and usually with a spider this small you'd be really squinting to even detect any. I'm really leaning towarding IDing it Tetraghanthidae, especially now since seeing those pics Jsloan linked to (thanks). The way that it sits seems to be the dead giveaway. How big do species of this genus typically get?
 

cacoseraph

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their name, tetragnatha, means "four jaws", in honor of those chelicerae
 

jsloan

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I'm really leaning towarding IDing it Tetraghanthidae, especially now since seeing those pics Jsloan linked to (thanks). The way that it sits seems to be the dead giveaway. How big do species of this genus typically get?
Well, first, "Tetragnathidae" is the family and Tetragnatha is the genus. The genus is a smaller grouping within the larger family. :)

In your area the largest examples will get up to around 1 inch to 1-1/2 inch leg spans. Medium-sized, I'd say.

There are some very colorful spiders in this genus. Here are some unidentified females I collected in Alberta a couple of years ago:
 

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jsloan

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Here's a picture of the inside teeth on the right chelicera of an adult male Tetragnatha extensa I found near those females (along the same river bank area). You can see how the fang would fit in the groove between the rows of teeth when the spider folds it up:

 

The Spider Faery

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their name, tetragnatha, means "four jaws", in honor of those chelicerae
Interesting fact. Also interesting is that I read that they can walk on water. No wonder mine's not a hydrophobe. It seems to really be okay when I spray water droplets in and goes over and 'gets its feet wet' so to speak and does what spiders do when they get their feet wet...puts them in its mouth. :p

Nice pics jsloan. Only time will tell when this little tyke gets bigger as to what it will look like and to better ID it.
 

zonbonzovi

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Beautiful shots, John. Most of these that I find are miniscule, but every so often we get some behemoths. Do you know what accounts for the size difference?
 

The Spider Faery

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Most of these that I find are miniscule, but every so often we get some behemoths.
Mine is currently miniscule at 10 mm's legspan. I assume it is a sling, but maybe it's just a tiny species. I hope it grows larger, but it is quite cute at this size also.
 

jsloan

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Beautiful shots, John. Most of these that I find are miniscule, but every so often we get some behemoths. Do you know what accounts for the size difference?
According to Dondale and Redner (2003), adult Tetragnatha in Canada range between about 4 mm and 13 mm for body length, depending on the species. I don't know why different species are different sizes, though.

That's the normal range for these spiders. Abnormally, some adults are smaller from eating less (food shortages), and some are smaller due to maturing after one fewer molt than normal. Some might also go through an extra molt (as Morse has observed in the crab spider, Misumena vatia), and so end up as larger adults than normal. But, those are exceptional cases.
 

cacoseraph

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That's the normal range for these spiders. Abnormally, some adults are smaller from eating less (food shortages),
i had baby G. rosea that were three years old and still around 1cmDLS :D they had ate less than 15 times in their lives at that point


That's the normal range for these spiders. Abnormally, some adults are smaller from eating less (food shortages), and some are smaller due to maturing after one fewer molt than normal. Some might also go through an extra molt (as Morse has observed in the crab spider, Misumena vatia), and so end up as larger adults than normal. But, those are exceptional cases.
boldmine
mmm, ideas
 

The Spider Faery

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My little Tetragnatha has died. I'm pretty sure that's what she was. I was able to inspect it closer once it died. There were definitely enlarged chelicerae. She was quite small, but I think she was adult size, since most of these species don't get very large. I found her at the bottom of the encosure curled up. Ah, r.i.p. Hailey.
 
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