#Arachtober 30: from July, a pair of _Tetragnatha_ long-jawed orbweavers mating. They normally mate hanging midair in a web, which makes them difficult to photograph; but this pair ended up on a solid surface, letting me get some better photos.

They mate face-to-face with jaws locked together, while the male reaches between them with a long pedipalp to transfer sperm to the female's epigyne (genital opening). The end of a mature male spider's pedipalp is an extraordinarily complex and dynamic organ, with bits that inflate to twist its configuration and allow it to fit into the epigyne, and every species is a little different. You can see illustrations of different _Tetragnatha_ palps here: https://araneae.nmbe.ch/specieskey/325/Tetragnatha

(The testes are not hooked up to the pedipalps or anything; the male's genital opening is in the abdomen, like the female's. Before mating, the male deposits sperm on a bit of web and draws it up into the pedipalps, as if with an extremely complicated turkey baster. Edit: for pics, see https://flipping.rocks/@nev/112636096285259211)

Spider sex is one of the most interesting things about spiders.

I'd say the pics are NSFW but if your co-workers fully recognize what they're looking at, you're probably arachnologists and this IS your job.

#DailySpiderPic #SpidersOfMastodon #SpiderSex • #Araneae #Tetragnathidae

#Arachtober 26: the cool weather is back and so the clover mites (_Bryobia_) are out! The tiny juvenile spiders plentiful now seemed unbothered by the crowds of mites scrambling around them.

#DailyMitePic #Mitestodon #arachnids #mites #CloverMites #DailySpiderPic #SpidersOfMastodon #spiders • #Acari #Tetranychidae #Bryobiinae #Araneae #Tetragnathidae

#Arachtober 20: the impressive mouthparts of a male _Tetragnatha_ long-jawed orbweaver!

Both chelicerae and pedipalps are multi-segmented and jointed—true for all spiders, but easier to see here because of the exaggerated anatomy. It points to their evolutionary/developmental origin as modified legs (what else?).

#DailySpiderPic #SpidersOfMastodon #spiders • #Araneae #Tetragnathidae

Put together a video of the long-jawed orbweaver making her egg sac! https://youtu.be/Ntymw7nCpuI

It's a mix of still photos and video segments, and much of the video is kind of repetitive, so see the timestamps in the description or use YT's chapter feature to skip ahead if you like. Or watch the whole thing for the immersive experience, I guess.

#DailySpiderVid #SpidersOfMastodon #spiders #SpiderBehaviour #Araneae #Tetragnathidae

BTW, here's what a long-jawed orbweaver egg sac looks like when complete. (I had to go home before our gal upthread was completely finished with hers, but got a pic of this fresh one by a spider who was making hers at around the same time.)

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On another tree I saw a courting male _Tetragnatha_ exuding a drop of semen onto a loose tangle of silk, then reach down and grab it with his pedipalps (the short appendages on either side of his jaws). In mature males, the palps are complex organs that are used kind of like turkey basters to inseminate females. I'd never seen this at all in any spider!!

Marked sensitive because, well, spider semen.

#DailySpiderPic #SpidersOfMastodon #SpiderSex #spiders #Araneae #Tetragnathidae #SpiderBehaviour