4 ms·

Catapulting spider winds up web to launch itself at prey

45 points by dnetesn 8y ago

beautifulfreak 8y ago
Here's a video https://www.youtube.com/watch?v=XiP2IcE-c5A https://www.youtube.com/watch?v=XiP2IcE-c5A
- deleted 8y ago
  [deleted]
- pelagic_sky 8y ago
  Thank you! Here's the same video, but starting a few seconds before the "catapulting" https://youtu.be/XiP2IcE-c5A?t=60 https://youtu.be/XiP2IcE-c5A?t=60
fifnir 8y ago
> Just when you thought spiders couldn't get any more terrifying. Why do we have to go for the same tropes again and again ? You're writing a science-dissemination article, is it really necessary to portray spiders as 'terrifying' ? They could have said "cool", "weird", "unique", "alien", i don't know i'm not the one getting paid to write stuff. But no, let's write this as if we're talking to middle-schoolers, ooooh scary spiders !!!!!!
- dmos62 8y ago
  In articles like these, I get the impression that the only substance is what is quoted or paraphrased from the actual article being talked about, and the job of the quoting author is to simply pump these out at a moderate speed, with added filler. The filler doesn't actually matter: it's just calming background noise for the actual content being "disseminated". If you were just provided quotes from the paper and illustrations, you'd feel like you're talking to a robot's notebook. The intended effect seems to be a minimally intellectual, maximally effortless, elevator-type anecdote-conversation. If you're making small talk with someone you hardly know on the elevator, you wouldn't care to criticize their viewpoints, right? I guess this is a long-winded way of describing click-bait.
  - amelius 8y ago
    https://en.wikipedia.org/wiki/Content_farm https://en.wikipedia.org/wiki/Content_farm
- dvtrn 8y ago
  Genuine question are you afraid of spiders? Am I correct guessing from your response here that’s a “no”?
  - fifnir 8y ago
    I used to keep tarantulas as pets and went on to study biology
    - dvtrn 8y ago
      Oh excellent! What was the most interesting thing you went on to learn about arachnids as a pet owner?
      - fifnir 8y ago
        Lots of little details.. Do you know how tarantulas mate? When a male has his ultimate (final) molt and reaches sexual maturity he is a completely different spider. During this ultimate molting process he obtained his sexual organs, which are bulbs (emboli, plural; embolus, singular) on the end of his pedipalps that are used to transfer sperm from his sperm web to the female. In many species males also have tibial spurs, which are "mating hooks" on the underside of the tibia (or long segment) of the first pair of walking legs and are used to engage the female's fangs during mating. taken from here: http://www.tarantulas.com/sexing.html http://www.tarantulas.com/sexing.html So the males dig a little hole, lay a sheet of silk over it and deposit their sperm in this little 'bowl'. Then they suck it up in what is effectively syringes that are developed at the end of their pedipalps. They use those to transfer the sperm to the female
        dvtrn 8y ago
        Do you know how tarantulas mate? I know what they look like, but--as alluded to in another comment, I have a touch of the fear of spiders due to a horrifying experience playing in the woods as a kid. The hilarious paradox here is that I find them incredibly interesting creatures to read and learn about. Just not look at. So the males dig a little hole, lay a sheet of silk over it and deposit their sperm in this little 'bowl'. Is this a reproductive process that's unique to tarantulas (in the arachnid kingdom, that is), this sort of "prepping" of the sperm before transferring to the female spider? I would guess it has to be based on what I recall--please give me the correction if I'm wrong-but most web dwelling spiders lay their eggs in webs, the tarantula likes dirt and soil, so their reproductive workflow demands a "dirtier" method? Sorry for the pun.
amelius 8y ago
"Catapulting" seems like the wrong word. The mechanism is described as: > When the spider releases the web, both spider and web accelerate forward very rapidly. The rapidly moving web tangles around the prey insect, starting the capture process from a distance. But this process starts when the prey is already in the web.
- pelagic_sky 8y ago
  Yeah, watching the video, it doesn't seem like catapulting at all. Entangling feels more accurate.

45 points by dnetesn 8y ago

beautifulfreak 8y ago

Here's a video https://www.youtube.com/watch?v=XiP2IcE-c5A https://www.youtube.com/watch?v=XiP2IcE-c5A

deleted 8y ago
[deleted]
pelagic_sky 8y ago
Thank you! Here's the same video, but starting a few seconds before the "catapulting" https://youtu.be/XiP2IcE-c5A?t=60 https://youtu.be/XiP2IcE-c5A?t=60

fifnir 8y ago

> Just when you thought spiders couldn't get any more terrifying. Why do we have to go for the same tropes again and again ? You're writing a science-dissemination article, is it really necessary to portray spiders as 'terrifying' ? They could have said "cool", "weird", "unique", "alien", i don't know i'm not the one getting paid to write stuff. But no, let's write this as if we're talking to middle-schoolers, ooooh scary spiders !!!!!!

dmos62 8y ago
In articles like these, I get the impression that the only substance is what is quoted or paraphrased from the actual article being talked about, and the job of the quoting author is to simply pump these out at a moderate speed, with added filler. The filler doesn't actually matter: it's just calming background noise for the actual content being "disseminated". If you were just provided quotes from the paper and illustrations, you'd feel like you're talking to a robot's notebook. The intended effect seems to be a minimally intellectual, maximally effortless, elevator-type anecdote-conversation. If you're making small talk with someone you hardly know on the elevator, you wouldn't care to criticize their viewpoints, right? I guess this is a long-winded way of describing click-bait.
- amelius 8y ago
  https://en.wikipedia.org/wiki/Content_farm https://en.wikipedia.org/wiki/Content_farm
dvtrn 8y ago
Genuine question are you afraid of spiders? Am I correct guessing from your response here that’s a “no”?
- fifnir 8y ago
  I used to keep tarantulas as pets and went on to study biology
  - dvtrn 8y ago
    Oh excellent! What was the most interesting thing you went on to learn about arachnids as a pet owner?
    - fifnir 8y ago
      Lots of little details.. Do you know how tarantulas mate? When a male has his ultimate (final) molt and reaches sexual maturity he is a completely different spider. During this ultimate molting process he obtained his sexual organs, which are bulbs (emboli, plural; embolus, singular) on the end of his pedipalps that are used to transfer sperm from his sperm web to the female. In many species males also have tibial spurs, which are "mating hooks" on the underside of the tibia (or long segment) of the first pair of walking legs and are used to engage the female's fangs during mating. taken from here: http://www.tarantulas.com/sexing.html http://www.tarantulas.com/sexing.html So the males dig a little hole, lay a sheet of silk over it and deposit their sperm in this little 'bowl'. Then they suck it up in what is effectively syringes that are developed at the end of their pedipalps. They use those to transfer the sperm to the female
      - dvtrn 8y ago
        Do you know how tarantulas mate? I know what they look like, but--as alluded to in another comment, I have a touch of the fear of spiders due to a horrifying experience playing in the woods as a kid. The hilarious paradox here is that I find them incredibly interesting creatures to read and learn about. Just not look at. So the males dig a little hole, lay a sheet of silk over it and deposit their sperm in this little 'bowl'. Is this a reproductive process that's unique to tarantulas (in the arachnid kingdom, that is), this sort of "prepping" of the sperm before transferring to the female spider? I would guess it has to be based on what I recall--please give me the correction if I'm wrong-but most web dwelling spiders lay their eggs in webs, the tarantula likes dirt and soil, so their reproductive workflow demands a "dirtier" method? Sorry for the pun.

amelius 8y ago

"Catapulting" seems like the wrong word. The mechanism is described as: > When the spider releases the web, both spider and web accelerate forward very rapidly. The rapidly moving web tangles around the prey insect, starting the capture process from a distance. But this process starts when the prey is already in the web.

pelagic_sky 8y ago
Yeah, watching the video, it doesn't seem like catapulting at all. Entangling feels more accurate.