Phyrex Posted June 6, 2004 Report Share Posted June 6, 2004 Is the time a VFT stay’s closed while absorbing a prey dependant on some sort of detection (of nutrients) mechanism or is it simply a set time or perhaps even dependant on how well it was stimulated when catching the prey? ^_^ Because the Royal Red I have, has it’s trap closed for over a week already. (There’s plenty of digestion juices inside and it made an awesome growth spurt since it has been fed btw :) ) I always thought the digesting time was always the same and about 5-7 days. This is also the case with my normal (green) Dionaea. Maybe Royal Reds have a longer period in general? Or could it be that the fat spider inside is soo sticky that it’s preventing the trap to open again? ;) Quote Link to comment Share on other sites More sharing options...
Phyrex Posted June 7, 2004 Author Report Share Posted June 7, 2004 Well ya the prey was rather large. :mrgreen: But what has a large prey to do with the trap not opening? Quote Link to comment Share on other sites More sharing options...
Guest Aidan Posted June 7, 2004 Report Share Posted June 7, 2004 There is no set size for prey items. However, prey that is so large that it can not be fully digested before bacterial decay sets in will usually kill the trap. You will notice the trap blacken and start to die without reopening. Quote Link to comment Share on other sites More sharing options...
Phyrex Posted June 7, 2004 Author Report Share Posted June 7, 2004 Aha, well I haven't seen any rot so far. But does anyone know what exactly causes the trap to stay closed? I mean I understand bacteria can kill it but why would the plant shut itself down and not reopen like normal? It must have a reason otherwise it wouldn’t have evolved to do so. I’m interested in the functionality behind it. :) Quote Link to comment Share on other sites More sharing options...
Tim Posted June 7, 2004 Report Share Posted June 7, 2004 Mine do that with butterflies sometimes. I think the reason my be much less profound, perhaps just the traps are stuck to the prey or something. Quote Link to comment Share on other sites More sharing options...
Brendan Posted June 7, 2004 Report Share Posted June 7, 2004 When a trap closes, water flows out of the water tracts (at the bottom of the trap/very end of the petiole) that keep the trap open. When a trap re-opens water is permitted to enter these tracts again. Reasons for this aren't to my knowlege! Quote Link to comment Share on other sites More sharing options...
Rogier Posted June 7, 2004 Report Share Posted June 7, 2004 My guess is that during the digesting of the prey, the trap "measures" how many nutricients are being obtained. When the amount of nutricients will lower because of the prey is being more and more digested, it could trigger the plant to stop digesting and open the trap. This way the plant would not spill energy, by keeping digesting on a already digested prey. But of course this is a wild guess from me. First time I actually started to think about it. Good question! Quote Link to comment Share on other sites More sharing options...
Phyrex Posted June 13, 2004 Author Report Share Posted June 13, 2004 Rogier: Yeah that would make sense. Nepenthes & Sarracenia plants do it like this right? At least if I recall correctly they detect nutrients and release more digestive enzymes. But on the other hand... the VFT already has a reasonable fail save mechanism to avoid wasting energy. Anyone ever tried activating a VFT twice so it closes completely and see if it has digestive fluids inside after some time? Although it still doesn’t give a final answer either because it might just be a small initial amount released and it would release more after detection... *sigh* ----- Well Starman, you were right, the overfed trap rotted away. :) Didn’t know it was related with the trap not re-opening though... Still haven’t heard the reason either. ^_^ Here are some of my ‘out of the blue’ wild theories: Take your pick or add your own please. 1) Bacterial growth killed the mechanism that made sure the trap would reopen. (The water thing Flookie talked about) 2) The trap could not close properly due to the size of the prey. Normally it closes/seals nicely around it’s prey but now it was very round. Maybe the plant tried closing completely for a few days but just wasn’t possible and over-used/depleted the trap closing/open mechanism by trying. Stressed out plant maybe? lol 3) Maybe the trap thought “Holy sh*t this is a good catch, initiate ‘never close’ procedure and absorb as many as I can before rotting away”. That would pretty much make a VFT guilty of the sin Gluttony. :x 4) The sheer size of the prey prevented water to re-flow into the re-open mechanism...? Someone call the plumber? 5) A VFT is able to detect how many nutrients are in it’s trap and will only open once their amount is low. But due to the super large prey this amount never is too low for the plant to re-open again so it sealed its own doom and will rot away. (Bit more logical version of 3) Someone please clear up whether a VFT detects nutrients inside the trap or not. If so I would pick option 5. Otherwise 2. ^_^ Whaddayathink? Quote Link to comment Share on other sites More sharing options...
Guest Aidan Posted June 13, 2004 Report Share Posted June 13, 2004 Or, ...... the trap had simply reached the end of its working life. Occam's razor! Quote Link to comment Share on other sites More sharing options...
Phyrex Posted June 13, 2004 Author Report Share Posted June 13, 2004 Or, ...... the trap had simply reached the end of its working life.Occam's razor! Hhm yes but how does it explain the relation with the trap not re-opening and the feeding of a too big prey? Quote Link to comment Share on other sites More sharing options...
Guest Aidan Posted June 13, 2004 Report Share Posted June 13, 2004 The most like answer to your question are those which have been already stated: 1> The trap has reached the end of its working life and died. or 2> Decay has set in before digestion has completed and killed the trap. The plant no doubt has a mechanism for determining whether or not the digestion cycle has completed. How that mechanism works....who knows? There is much about plant carnivory that is still not understood. The simplest answer is usually the correct one, anything else is unnecessarily complicated speculation. Quote Link to comment Share on other sites More sharing options...
Frederick Posted June 13, 2004 Report Share Posted June 13, 2004 VFT and Drosera traps are receptive for Nitrogen. Altough VFT's have trigger hairs, which causes them to stay closed in the long run (trigger hairs for the short time after closing detect a living prey) is Nitrogen, just like in sundews. Although Darwin's explenation on the working of the traps aren't really the most up to date, his experiments on what makes a trap do it's job can be found here, very good reading : http://pages.britishlibrary.net/charles.da...us/insect01.htm Fred Quote Link to comment Share on other sites More sharing options...
Guest Aidan Posted June 13, 2004 Report Share Posted June 13, 2004 A few relevant pages from Barry Rice: http://www.sarracenia.com/faq/faq2290.html http://www.sarracenia.com/faq/faq2400.html http://www.sarracenia.com/faq/faq2410.html Quote Link to comment Share on other sites More sharing options...
Phyrex Posted June 13, 2004 Author Report Share Posted June 13, 2004 The simplest answer is usually the correct one, anything else is unnecessarily complicated speculation. I'm sorry but I don't agree with that. My interest for carnivorous plants not only lies in it’s beauty but also in the strangeness of the designs and the idea how they evolved into effective plants who are able to thrive where no other plants can. Being able to understand all the mechanisms and their functions makes me appreciate the plants much more. When I see a flower I think "Why 5 petals and not 4 or 6?" instead of just "Wow, nice flower *drool*". Excuse my curiosity. Quote Link to comment Share on other sites More sharing options...
Brendan Posted June 13, 2004 Report Share Posted June 13, 2004 Maybe this question could lead to an explanation. VFTs secrete digestive enzymes when the prey is caught in the trap. Is this solution acidic? Reasoning: Bacteria can't live in acidic conditions. Therefore bacteria attack on the trap could only occur if the digestive solution has gone after the trap has absorbed nutrients, no digestive solution has been produced, or the solution isn't acidic at all. It also depends what kind of bacteria we are talking about, anaerobic, aerobic...? Is it even bacteria at all? Quote Link to comment Share on other sites More sharing options...
Guest Aidan Posted June 13, 2004 Report Share Posted June 13, 2004 The simplest answer is usually the correct one, anything else is unnecessarily complicated speculation. Note the use of the term 'usually'. William of Occam died in 1350. This is a form of Occam's Razor and it has survived to this day because it is more often proved right than wrong. I'd be interested to know if you can find a single example of where nature has chosen to implement any mechanism the 'hard way', when a simple and elegant solution is available. Quote Link to comment Share on other sites More sharing options...
Brendan Posted June 13, 2004 Report Share Posted June 13, 2004 How can you be sure of that Starman? Quote Link to comment Share on other sites More sharing options...
jimscott Posted June 13, 2004 Report Share Posted June 13, 2004 My green dragon recently caught a "daddy longlegs" but opened up a day later. Why did that happen? Was there not enough to say so? Since it was outside, I doubt someone placed a dead spider in the trap. Quote Link to comment Share on other sites More sharing options...
olly_k Posted June 13, 2004 Report Share Posted June 13, 2004 My green dragon recently caught a "daddy longlegs" but opened up a day later. Why did that happen? My guess would be that because of the size of the D/longlegs, once the trap partially closed, the fly was not able to trigger the hairs enough to fully close the trap, so the VFT thought there was nothing worth digesting?? and so opened straight back up? Quote Link to comment Share on other sites More sharing options...
jimscott Posted June 14, 2004 Report Share Posted June 14, 2004 Hmmm, that's plausable. Quote Link to comment Share on other sites More sharing options...
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