My mother sent me a picture of a creature she encountered and couldn't identify. It looks kind of a like a spider - a mostly black body, about 1cm in size, with white specks - except without any visible legs. Apparently it was hanging from a thread, descending to the ground, and still moving.

I don't know a lot about arthropods, and, perhaps unsurprisingly, searching for "spider without legs" gives no useful results, so I'm at a loss.

This is in Northern Germany, mid-March. (The background is a cork floor.)

Unknown arthropod

Any info on what this could be - and whether it's dangerous or not - would definitely help put her at ease.

  • $\begingroup$ ID chances are much higher if you photo the top side. Perhaps fiip him with a piece of card, that looks like it's feigning to be dead, trying to look like a stone. $\endgroup$ – DeltaEnfieldWaid Mar 21 at 7:44

This appears to be the underside of a walnut orbweaver:

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These orbweaver spiders are not medically significant.

Spiders often lose their legs in wasp attacks. Some spider wasps will remove the legs and then try to bring the spider to its nest for larvae to feed on. Sometimes they drop their spider victims accidentally.

Some will simply deposit eggs into the spider and leave it there, letting the larvae grow inside the spider and feeding on it from the inside.. these ones don't usually remove the legs - they usually just paralyze the spider.

Spiders can lose their legs through various attacks, but they can also lose their legs in molting accidents... particularly if they are in the middle of a molt and then are aggressively interrupted.

  • $\begingroup$ This is a great answer, so interesting and informative! +1 (more if I could). Where did you find out about the... unseemly... wasp behavior? Do they also decapitate their prey? I'd like to read more. Thanks! $\endgroup$ – anongoodnurse Apr 11 at 2:52
  • $\begingroup$ Thanks! Here is a video of a wasp removing legs... it says 'spider' but it appears to be a harvestman ("daddy long legs"): youtube.com/watch?v=NwPuhVS2RhE But that's not a spider wasp... that one is just using it for meat. Here is a spider wasp, which will be using the spider to grow a larvae: youtube.com/watch?v=rs_Q7S3Rxkk and: youtube.com/watch?v=9tfblWSdEHs and here's one with the act of removing legs: youtube.com/watch?v=BKZAsxHAV7w $\endgroup$ – JimN Apr 11 at 8:12
  • $\begingroup$ @anongoodnurse Found another video of the full process (the hunt, the attack, leg removal, and carry-away): youtube.com/watch?v=a592T6KmwmU $\endgroup$ – JimN Apr 11 at 9:12
  • $\begingroup$ BTW - I'm not convinced this was the fate of the spider. The question poser said it was descending down a silk line. I think @aliential is correct that it was probably feigning a dead pose. It looks like you can see some of the legs against the body (the hind leg on the abdomen and the tarsus/foot slightly covering the ventral white mark) $\endgroup$ – JimN Apr 11 at 9:15
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    $\begingroup$ Thanks for the reply. Those videos... omg. Nature is really red in tooth (or mandible) and claw. Your comments led me to explore and learn. I hope you're right about this spider's fate. I like spiders, especially orbs and jumping spiders. $\endgroup$ – anongoodnurse Apr 11 at 16:41

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