How long does it take for Tarantula venom to kill its prey?

[Ezekiel400lux]

I've learned about how potent the TS venom is against small animals especially their prey. I just fed my King Baboon a regular-size Dubia and the roach just happened to be wiggling while held by the Tarantula's fangs for almost 7 minutes - which made me wonder how strong their venom is if it the roach wasn't immediately dead after the TS made its bite.

 

[Gevo]

I think it could depend on a lot of things: species of tarantula, size of tarantula, size of prey, type of prey, where they place their bite...

My understanding is that tarantula venom (very generally speaking because they have different types and potencies!) is mostly meant to paralyze prey and begin digesting it, so it doesn't always kill the prey directly. I think the insects you feed the tarantula mostly die from being sucked dry as the digestive compounds get to work. Roaches also have nervous systems that allow them to keep moving and twitching even after being decapitated, so that might also be a factor in your case, though I notice that crickets continue to move for a bit too and my tarantulas usually go up on their tiptoes when feeding while their prey is still moving a bit.

If you're interested, here's an article with some cool information about how tarantula venom is being studied and what they've found about how it affects human nervous systems: https://www.wired.com/2016/06/tarantula-toxins-teach-us-science-pain/

 

[SpookySpooder]

What if it doesn't kill them but just paralyzes and digests them? I've seen feeders twitch until the moment they are rolled into a bolus...

 

[Tentacle Toast]

What if it doesn't kill them but just paralyzes and digests them? I've seen feeders twitch until the moment they are rolled into a bolus...

Man, watching bugs eat other bugs is downright horrifying, LoL

 

[l4nsky]

IIRC, the venom incapacitates and death usually results from physical trauma like mastication via the chelicera or a lucky fang piercing something vital in the initial capture.

 

[jbooth]

Yes, long after it has been ripped to shreds. Some seem very fast, like H. gabonensis though, those little suckers go back for another like 5 seconds later and the first is done twitching.

 

[corydalis]

What if it doesn't kill them but just paralyzes and digests them? I've seen feeders twitch until the moment they are rolled into a bolus...

Legend says that some feeders even twitch as a bolus..

 

[viper69]

I've learned about how potent the TS venom is against small animals especially their prey. I just fed my King Baboon a regular-size Dubia and the roach just happened to be wiggling while held by the Tarantula's fangs for almost 7 minutes - which made me wonder how strong their venom is if it the roach wasn't immediately dead after the TS made its bite.

Most damage is done by mastication not venom

 

[Kada]

Sometimes their fangs miss altogether and seem to be more like chopsticks

 

[Biancaxoxox]

I've learned about how potent the TS venom is against small animals especially their prey. I just fed my King Baboon a regular-size Dubia and the roach just happened to be wiggling while held by the Tarantula's fangs for almost 7 minutes - which made me wonder how strong their venom is if it the roach wasn't immediately dead after the TS made its bite.

Depending on what species we’re talking about…. but maybe 2 maybe 3

 

[The Snark]

I think it could depend on a lot of things

So the answer is somewhere between never and weeks of slowly advancing debility. Give or take a pineapple.

 

[spideyspinneret78]

Depends on the species and the type of prey.

 

[Olan]

Roaches especially seem to keep moving till totally masticated.
But they’re also the animals that can run around without a head…

 

[klawfran3]

When it comes to determining "how quickly does venom take effect" or "how venomous is this animal", it's a very hard thing to determine. Different types of animals will have different reactions to the venom. A great example is with Atrax spiders, the funnel webs in Australia. Humans get absolutely wrecked by the venom, and a small dose can easily kill someone. Dogs and cats, on the other hand, are mildly effected if at all and would need a very large amount to die from it.

This is why scientists use whats called an "LD50" to work with toxins***. LD stands for "Lethal dose" and 50 is the percentage of individuals to die. Basically at what concentration of this toxin will cause half of all subjects of this species to die. It's usually measured in milligrams of toxin per kilogram of body weight (mg/kg). This allows us to compare toxicity rates, since killing a median amount of individuals seems to be a relatively good way to compare toxicity between groups and toxins.

Let's make up an example. A theoretical viper that eats mostly birds in tree canopies has its venom sampled. When this venom is injected into 100 house sparrows or pigeons (model species we use in labs), 50 of them die at the dose of .001mg/kg. When we inject it into 100 mice, 50 of them die at .15mg/kg. When we inject it into 100 macaques, 50 die at .02 mg/kg. So the mice seem to be significantly more resistant to the venom than the both birds and monkeys do, despite mice being closer in size to the birds in the study.

This is what makes studying the toxicity of venom so hard, because all the different groups of animals will have varying reactions just due to how their bodies metabolize certain things, how their biological pathways are setup, or how different their anatomy is. This is what makes an LD50 so useful, because we can compare it across different species and say "venom A is more toxic to mice than venom B, but it is less toxic to birds than venom B." And get a reasonably more standardized comparison than we would otherwise.

All that being said, I don't think anyone has done a study on the LD50 for any tarantulas. And we also know that different Ts do a hell of a lot more damage to us with their venom than others (pokies vs brachys), but this doesn't translate to how easily it kills their prey animals.

Plus most tarantulas are large and strong, and venom is biologically expensive to make, so they're not going to waste it on a cricket or roach when they can just overpower it and crush it up instead. This is why so many roaches and bugs twitch for hours after being caught. They weren't injected with venom at all, and their decentralized nervous system makes it pretty easy for them to handle severe trauma and disfigurement. Tarantulas very rarely inject their prey with venom, and unless they have a large prey animal like a vertebrate they're unlikely to do so.

***Also tangentially and not as important, but there can be LD95s and LD20s and LD1s (or whatever percentage you want to die) to determine some trait of the venom you want to figure out like "what's the maximum amount of venom that individuals of this species can take before any of them die" or "what's the minimum amount of venom we can give this species to kill all individuals". Toxicology is fun and teaches us so much but you kill a LOT of model organisms. It's not for the faint of heart.

 

[Olan]

There are a very few actual toxicology studies on T venom floating around:

Pharmacological analysis of Poecilotheria spider venoms in mice provides clues for human treatment - PubMed

Bites of tiger spiders belonging to Poecilotheria genus cause moderate to severe pain and long-lasting local or generalized muscle cramps in humans. Bites occur in regions of the spiders' natural habitat, India and Sri Lanka, but the popularity of these colorful tarantulas as pets leads to...

pubmed.ncbi.nlm.nih.gov

Tarantula LD50 information?

Hey, I'm potentially going to be doing a meta analysis on tarantulas for my third year project at uni. The focus would probably be on indicators of toxicity (I'd love to do aggression but its too subjective) for which I'd require comparable toxicity information. I've been seaching out ld50...

arachnoboards.com

But not much