Random, Non- Urgent T questions

Sarkhan42

Sarkhan42

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Venom1080 said:
Common sense.. always thought it was more for defense. NWs have their hair, ows have their speed and venom. Venoms not something to be used lightly either, hence why dry bites sometimes occur.. perhaps if they have a big enough prey item.

I always assumed it worked like this for a very long time.
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Without specific citation of a study of this, I’m going to be extremely skeptical. While you state it’s common sense, based off of the composition of the majority of studied venom that seems to be incredibly unlikely to be the case. While yes venom can be used in defense, “the majority of characterized spider-venom peptides target voltage-gated potassium (KV) [25], calcium (CaV) [26,27], or sodium (NaV) [26,28] channels.”(Natalie J. Saez, Sebastian Senff, [...], and Glenn F. King) Aka are made to shut down processes essential to nervous system function. In addition to this, “Most of these peptides contain a unique arrangement of disulfide bonds that provides them with extreme resistance to proteases. As a result, these peptides are highly stable in the insect gut and hemolymph”(Glenn F. King and Margaret C. Hardy) another piece of evidence showing that venom is specified to be especially potent in invertebrates, which would be contradictory of a hypothesis in which venom is primarily used for defense, in that most predators would likely be non invertebrate for many species.

All of this being said, you may ask wether these venoms studied are specific to theraphosidae, and unfortunately the closest I was able to directly find was citation of macrothele venom. However, we do know theraphosid venom is being studied for medicinal purposes (thrixopelma puriens specifically I believe) and I would assume that if the composition was noticeably different we would be able to find it stated.
 
Venom1080

Venom1080

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Sarkhan42 said:
Without specific citation of a study of this, I’m going to be extremely skeptical. While you state it’s common sense, based off of the composition of the majority of studied venom that seems to be incredibly unlikely to be the case. While yes venom can be used in defense, “the majority of characterized spider-venom peptides target voltage-gated potassium (KV) [25], calcium (CaV) [26,27], or sodium (NaV) [26,28] channels.”(Natalie J. Saez, Sebastian Senff, [...], and Glenn F. King) Aka are made to shut down processes essential to nervous system function. In addition to this, “Most of these peptides contain a unique arrangement of disulfide bonds that provides them with extreme resistance to proteases. As a result, these peptides are highly stable in the insect gut and hemolymph”(Glenn F. King and Margaret C. Hardy) another piece of evidence showing that venom is specified to be especially potent in invertebrates, which would be contradictory of a hypothesis in which venom is primarily used for defense, in that most predators would likely be non invertebrate for many species.

All of this being said, you may ask wether these venoms studied are specific to theraphosidae, and unfortunately the closest I was able to directly find was citation of macrothele venom. However, we do know theraphosid venom is being studied for medicinal purposes (thrixopelma puriens specifically I believe) and I would assume that if the composition was noticeably different we would be able to find it stated.
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Well, until you do. I think I'll continue to believe that they don't use venom for taking down weak prey. But I won't spread it as truth either.

I know they sort of vomit digestive fluids on prey that turns it into a bolus. But I'm still very much in the dark on the whole eating process.

@AphonopelmaTX I imagine you could clear this up..
 
Sarkhan42

Sarkhan42

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Venom1080 said:
Well, until you do. I think I'll continue to believe that they don't use venom for taking down weak prey. But I won't spread it as truth either.

@AphonopelmaTX I imagine you could clear this up..
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I found one! https://link.springer.com/article/10.1007/s00018-010-0359-x

“C. crawshayi show a high similarity with genes or peptides from spiders and proteins families of other arthropods.”

There’s a lot more to the paper as well, including a section on the effects of the venom on crickets specifically.
 
G

Garth Vader

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Chris LXXIX said:
Uhm, that cheese doesn't looks so yummi :shifty:

On the other hand, Italian cheese with living worms inside (Casu marzu*) is a Delicatessen, a food for Kings :hungry:

:rofl:

*https://en.wikipedia.org/wiki/Casu_marzu
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Oh no, it's really bad. Not yummy at all. It's one of those things that will be around long after the human race is extinct: roaches, twinkies, velveeta.
Cheese with living worms? Interesting. :pompous:

Now I will stop posting here about cheese here because we've done a major thread derailment here! :)
 
Sarkhan42

Sarkhan42

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Venom1080 said:
Well, until you do. I think I'll continue to believe that they don't use venom for taking down weak prey. But I won't spread it as truth either.

I know they sort of vomit digestive fluids on prey that turns it into a bolus. But I'm still very much in the dark on the whole eating process.

@AphonopelmaTX I imagine you could clear this up..
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“Several insecticidal peptides from Brachypelma spp. have been described; toxin Bs1 from B. smithi [23] and the peptides Ba1 and Ba2 from B. albiceps[24] are peptides which have been shown to be toxic for crickets, but not for mice.”
 
Venom1080

Venom1080

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Sarkhan42 said:
I found one! https://link.springer.com/article/10.1007/s00018-010-0359-x

“C. crawshayi show a high similarity with genes or peptides from spiders and proteins families of other arthropods.”

There’s a lot more to the paper as well, including a section on the effects of the venom on crickets specifically.
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Edit don't know where you found that part..

That would imply they use venom for smaller prey.. but it still doesn't make sense to me.
 
Sarkhan42

Sarkhan42

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Venom1080 said:
Very nice and all.. but I'm not paying 40 bucks for it..

Quite doesn't answer the question either.
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You can access the discussion and results for free... and later on they state that they’re nearly identical to other arachnids. Plus with the excerpt from my other post, they speak to specific action of the venom on crickets. I suppose if you want to be very technical it doesn’t test when they use and when they don’t use venom.
 
Sarkhan42

Sarkhan42

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Venom1080 said:
Identical as in they use venom for every takedown?
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Just edited my post to include this as you responded. That’s something that’s likely difficult to test, in that any extra resistance in attempting to retrieve prey to test for venom can result in a release of venom by your theory. I’m simply stating that via the evidence it would not only not make sense for their venom to be primarily defensive, but even be specifically targeted at average invertebrate prey, if it was only for large prey it wouldn’t make sense for it to be less effective in small vertebrates. I suppose it all comes down to prey variance in the wild, if they’re coming across large invertebrates regularly than perhaps your theory may have merit.
 
Venom1080

Venom1080

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Sarkhan42 said:
Just edited my post to include this as you responded. That’s something that’s likely difficult to test, in that any extra resistance in attempting to retrieve prey to test for venom can result in a release of venom by your theory. I’m simply stating that via the evidence it would not only not make sense for their venom to be primarily defensive, but even be specifically targeted at average invertebrate prey, if it was only for large prey it wouldn’t make sense for it to be less effective in small vertebrates. I suppose it all comes down to prey variance in the wild, if they’re coming across large invertebrates regularly than perhaps your theory may have merit.
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I agree. Hence my last post.

I figured it would be wasteful to use venom on a prey item that's going to be near torn in two on impact.
 
Sarkhan42

Sarkhan42

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Venom1080 said:
I agree. Hence my last post.

I figured it would be wasteful to use venom on a prey item that's going to be near torn in two on impact.
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It’s fascinating considering the assumed sequence of evolution in arachnids. I can only assume it’s due to their prey in the wild, and the defensive measures said prey can take. We only know them to take down what we feed them, but who knows what kind of dangerous insects they run into in the wild. Hell we’ve seen superworms munch on spiders while in their fangs, what else could do similar?
 
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