11 ms·
Newly discovered spider builds spring loaded snare to catch ants
- matheusmoreira 3mo agoI wonder why biological organisms are capable of such absurdly high accelerations. Article reminded me of cnidocytes which apparently produce anywhere between 40,000 and 5,410,000 g. Is it because of the small masses involved?
- ajuc 3mo agoStrength of fibers scales with crossection area, mass scales with volume.
- salynchnew 3mo agoThere are probably some other interesting adaptations involved, like the fact that the surface of a mantis shrimp's (shell? carapace?) selectively filters out sound waves (and thus, shockwaves caused by its own "punch").
- pvaldes 3mo agoIf they would prove that the trap also breaks the ant neck, saving venom, or stunning the prey for easy kill, that would be incredible. Somebody needs to include this thing in the script of a science fiction film.
- euroderf 3mo ago> Somebody needs to include this thing in the script of a science fiction film. "The Fly" is ready for a quick rewrite.
- Foskya 3mo agoIt is truly fascinating, I wonder how it evolved like that. Before becoming a spring as it is today how was it hunting in the past? What constraints made it need such a mechanism instead of a typical web?
- pvaldes 3mo agoInjured Himenoptera are known to send pheromones that trigger a vicious defensive response from other members of the colony. On a typical web the companion ants would do what the ants do. Go to war and flood the place surrounding the danger until eventually killing it. The spider does not have neither the stamina, nor the venom amount to deal with that. This web is designed to extract just one ant, while cutting the path that the ant rescuers could follow. This is the first spider web known designed to catch only one species of prey. That alone would make the finding extraordinary. The trap can lure only green ants and serve the food exactly were the spider wants it; granting access to a common source of food that is everywhere, but also that is very dangerous to hunt (as much big as the spider, with powerful jaws, and much stronger). The video shows one most interesting thing: Notice that the spider is carefully moving out of the way, just a second before the ant is launched. The spider knows in advance that its current location is about to be hit by a bungee jumping ant, and acts accordingly just in time to avoid the "bullet". We can easily imagine the spider thinking 5,4,3... This means that spider brains can predict the future outcome of a complex movement of objects in the physical system of its trap, and also calculate how much time the fibers will resist the jaw of the ant.
- sethammons 3mo agoThe smart spider is portia, a jumping spider. A quick search uncovers zounds of videos, articles, and scientific publications on them. They specialize is hunting spiders, changing hunting tactics based on type and number of prey. Yes, they count. They strategize. They make multi-step plans that take them out of sight of prey. And some people keep them as pets.
- chrisweekly 3mo agoYes! I learned about them reading Adrian Tchaikovsky's excellent scifi book "Children of Time".
- vharuck 3mo ago>And some people keep them as pets. I can personally vouch for them being great pets. They're active during the day, hunt prey, don't need much food or water, and tend to "hide" in silk cases they build along the top of their terrariums so you can always see them. They like to get water from inside flowers, and probably can differentiate between many colors, so adding bright flowers not only makes things prettier, it provides a watering hole and possible hunting advantage over color-blind insects trying to hide. Of course, if you don't want to set up a terrarium and personally sentence crickets to death, just look at the screens in your windows. Odds are, a jumping spider is already living there and will stay as long as you let it. They're territorial.
- pvaldes 3mo agolink to the paper here: https://news.ycombinator.com/item?id=48635929 https://news.ycombinator.com/item?id=48635929
- kiproping 3mo agoThe videos are amazing. Sadly I think theses types of adaptations make it easier for the species to go extinct since its so highly specialized.
- gyanchawdhary 3mo ago>theses types of adaptations make it easier for the species to go extinct since its so highly specialized. super interesting. I'm guessing because being highly dependent on a single tactic can make it difficult to adapt or course change ?
- soulofmischief 3mo agoAs a general rule of dynamical systems, specialization is essentially the exploitation of regularity within your environment. A highly regular environment can allow for extreme specialization because a system can predict and "expect" certain situations. This leads to much less energy expended, since maintaining stability requires energy that scales with the turbulence of a system. If gravity is always down, you don't need to spend energy on organs that overcome gravity in other directions. Your circulatory system can use gravity to its advantage; that's why you can't just remain upside down, there's no effective mechanism to pump blood out of your brain. If a car passes a street exactly every 2 minutes, you don't need to spend lots of time and energy figuring out when to cross. You know once a car crosses, you're good for 2 minutes. If you know the sun comes up around the same time every day, you can allow yourself a deep sleep during the night if you're in a safe place, or bloom only during the day. Nature exploits such regularities in order to reduce the energy needed to maintain an organism or group, which creates specialization, whether on the scale of the group, on the scale of the individual, etc. This is hierarchical; your cells specialize, your organs specialize, you get training or education to specialize your skills, etc. For example, you might specialize as a software engineer, depending on the regularity of people willing to pay money for you to solve their problems, but AI comes around and suddenly you're out of a job. The danger is that the more regularities you depend on, the less free energy your body needs to keep around and the less free energy you have to suddenly react and adapt to a new environment. If tomorrow, gravity started being up and not down, most of us would have a bad time. If those regularities are interdependent, as geological/biological cycles tend to be, a few bad conditions could unravel the entire ecosystem.
- tclancy 3mo agoIt is the year 2038. A new brand of slingshot is almost immediately removed from store shelves after multiple children receive through-and-through wounds.
- amarant 3mo ago[dead]
- enjrolas 3mo agoThe part from the paper which is so interesting is why the ant bites the trap in the first place. The paper suggests that the spider puts out a pheromone that attracts the ant and triggers the ant to aggressively bite the snare, but the pheromone only does this for the spider's target species, the green tree ant. The researchers watched three other ant species check out the snare, go "meh", and move on, unharmed, without showing any aggression towards the snare.
- abrookewood 3mo agoYeah, that is pretty crazy. I wonder what it smells like? Has to be an enemy specific to that ant species right?
- enjrolas 3mo agothat's a good question -- the paper describes it triggering aggression in the ant within milliseconds of it probing the snare with its antenna. I don't know the basis for it, but that's some down-to-the-metal ant programming right there
- mc_maurer 3mo agoYou should read up on manipulative parasites too! Things like wasp larvae developing inside an insect and changing its behavior through chemical manipulation of neural pathways. Some really remarkable specialization!
- abrookewood 3mo agoYep, I love that stuff .. just crazy to think how it all came about.
- mc_maurer 3mo agoUltimately, it's probably due to the rate of encounter with this species and the evolution of the pheromone towards the most consistent and intense response from that particular species. It's likely that a more general pheromone wouldn't induce such a consistent response, since it would be a less specific and reliable cue from the ant's perspective. So if you encounter lots of different ant species, a more general pheromone with a 50% response rate could work, but if you primarily encounter this ant species, a more specific pheromone with a 90% response rate is going to confer a greater fitness advantage. Could be due to the rate of encounter with this species vs. other species, could also be due to the consistency of response with more general vs. specific pheromones. You start with spiders with silk/pheromones that ants are a little more aggressive towards, then variance in that chemical makeup leads to fitness advantages. If the pheromone confers a strong advantage in a specific ant,
- jimnotgym 3mo agoHN pedantry time: >discovered a remarkable new spider species... Recently evolved then? Or perhaps... "An international team of researchers has recently discovered a remarkable spider species..."
- jagged-chisel 3mo agoIt’s a new discovery for humans.
- chrisweekly 3mo agothat's precisely their point
- jagged-chisel 3mo agoNot seeing the "problem." To humans, it's new. It's a new addition to the list of "species we know about." It's a new spider species. This is how language has been used for a long time.
- dofm 3mo agoThe notion of a species only really exists in the human world; it's a human concept. So the discovery of a new species is the discovery of a new classification need. It is new to science. (At a first approximation, essentially all existing species are new on an evolutionary level — isn't it the case that something like 99.9% of all life on earth is newer than a million years old?)
- NitpickLawyer 3mo agoHeh, for a second there this read like some of the Portiid adventures with Bianca and Fabian from Adrian Tchaikovsky's book "Children of time". If you find this kind of thing interesting and are a fan of sci-fi, I highly recommend the book.
- spidercat 3mo agoChildren of Time is one of the best books I've ever read, it's honestly amazing. It might be my all-time favorite. Seconding this recommendation!
- zacharyfmarion 3mo agoThirding it! This is your sign, go read it
- TooSmugToFail 3mo agoOk, this was my sign.
- imzadi 3mo agoI don't think I've been disappointed by anything from Adrian Tchaikovsky, tbh. Alien Clay and Service Model are also great.
- thingification 3mo agoI read Alien Clay and another book by him, which it turned out is basically the same book, which I found disappointing.
- fmajid 3mo agoThe only thing I've read of him is Elder Race, which was meh. I'll try Children of Time.
- tinyplanets 3mo agoChildren of Time is fantastic! I ended up totally rooting for the spiders in the end.
- chrisrickard 3mo agoOf course it’s an Australian spider
- taf2 3mo agothis gives me children of time vibes
- som 3mo agoI'm from where these spiders were found. The ants they're predating are an equally fascinating and super aggressive species of green weaver ants (that have other cool predators like "mimic" jumping spiders). https://en.wikipedia.org/wiki/Weaver_ant https://en.wikipedia.org/wiki/Weaver_ant
- qurren 3mo ago"Just a quick check" ... no thanks. Bounced. Just deliver me the information when I send a request, I didn't ask to be checked.
- INTPenis 3mo agoSpeaking of clever animals, I just recently learned about the Australian birds that cause wildfires to drive out small game that they can catch. https://www.nationalgeographic.com/animals/article/wildfires-birds-animals-australia https://www.nationalgeographic.com/animals/article/wildfires...
- seethishat 3mo agoSome spiders seem to think, recognize people and take immediate evasive action. Contrast that with a beetle, or ant. They just keep walking along like I'm not even there. I turned the kitchen light on once and saw a spider in the middle of the floor. It ran straight under the fridge. It would peek out occasionally to see if I was still there. That's why spiders scare me.
- AceyMan 3mo agoSpiders are insectivores and have little to no interest in you. That's why I love them. When you have spiders, you don't have pesty insects, in the same way that when you have cats you don't have rodents.