'Why"

[Malhavoc's]

Why is it that some scorps have abnormaly large 'fat' tails.. What is the point of this evolutionary wise?

 

[Runaway987]

To look like a badass

 

[WorldTour]

To hold more venom would be my guess. As for looking like a badass... I guess they got to do something to draw attention to themselves since the ultimate badass scorpion doesn't have a fat tail.

-Mark

 

[carpe scorpio]

The powerfully built metasoma is used to push out the sand/soil that the scorpion has dug loose. I have noticed that Androctonus rely heavily on this. They are also less vulnerable to predators that would tear off the tail of a more lightly built species.

 

[buthidae46290]

The powerfully built metasoma is used to push out the sand/soil that the scorpion has dug loose. I have noticed that Androctonus rely heavily on this. They are also less vulnerable to predators that would tear off the tail of a more lightly built species.

Its always nice to hear an answer from someone who knows what they're talking about(thats why I didn't post anything here before, my guess would have been similar to the first two, lol).

 

[carpe scorpio]

Thanks, but even though there are several burrowing species with vastly differing chela to metasoma proportions, if enough of the scorpions that have larger "tails" survive to breed, that genetic characteristic would be passed on. There are probably other factors involved as well.

 

[WorldTour]

There's always someone coming in and killing the the Smartass' fun... ;P haha
-Mark

 

[Fergrim]

I feel -that- pain, Mark. And I always thought the size of the tail was a good indicator of how venemous it is.. Or at least how willing it'd be to sting

 

[carpe scorpio]

I feel -that- pain, Mark. And I always thought the size of the tail was a good indicator of how venemous it is.. Or at least how willing it'd be to sting

Well, there is an inverse relationship(typically) between venom and chela size. Having a more powerful metasoma to defend itself and deliver venom with certainly has it's advantages. And by the way, only the vesicle of the telson contains the venom glands.

 

[Malhavoc's]

So why arn't scorps brghtly coloured? wouldn't it be easier to say "Hey I CAN kill you.." rather then waist all that venom to sting.. [and yes I know not many of them are deadly..]

 

[carpe scorpio]

So why arn't scorps brghtly coloured? wouldn't it be easier to say "Hey I CAN kill you.." rather then waist all that venom to sting.. [and yes I know not many of them are deadly..]

That may have something to do with a specific scorpion's habitat and whether or not any birds etc. are looking to eat them. Some species of Tityus are beautifully colored however.

 

[carpe scorpio]

One interesting observation with Androctonus is that after they nail a cricket, they turn so that anything attempting to enter the scrape or burrow is confronted by that massive metasoma.

 

[Nazgul]

Hi,

there are even some hints that some species might be evolving the metasoma as a sensory organ. A really interesting paper about it is this one:

FET E.V., NEFF D., GRAHAM M.R. & V. FET (2003): The Metasoma of Orthochirus (Scorpiones: Buthidae): Are scorpions evolving a new sensory organ? – Revista Iberica de Arachnologica Vol. 8: 69–72
It can be downloaded here: http://www.science.marshall.edu/fet/euscorpius/fetpubl/Ortho.pdf .

I guess a massive meatosoma is often used as a shield to defend the body. Burrowing species are protected against enemies coming from above by their burrows. However do they have to protect the entrance of their burrow. Massive chelae are useful doing this whereas a massive metasoma is not needed. Furtheron a large metasoma could be hindering while agitating in the small space of a burrow. On the other hand do a few species with massive metasomas burrow. But as mentioned they are often protecting the entrance with their tail. One should have a look if those species are pure sit-and-wait hunters like for example some Opistophthalmus spp or if they are leaving the burrows from time to time. But as Stan said a lot of factors are involved in the process of evolution and trying to know all will end up in speculation I guess.

Scorpions are having a lot of predators. A few are immune against the venom and a lot developed certain techniques to avoid being stung. I guess for being extra colorful scorpions are not venomous enough. The coloration of some Tityus spp is some kind of "mimese" (I don´t know the english expression) for being invisible against a background of bark I think.

Greetings
Alex

 

[Malhavoc's]

Camaflouge? IO think thats what you mean and all of this sounds very intresting. so if it is another sensory organ, what do you think it senses?

 

[carpe scorpio]

Alex, this information regarding the metasomal pits of Orthochirus is absolutely fascinating, I had not heard of this, thanks for the PDF.

 

[fusion121]

Interesting article Alex, the other sensory function of the metasoma thats been studied a bit is its light sensitivity: "Zwicky, A light response in the tail of urodacus, a scorpion" is a good paper on the topic, apparently scorpions are able to detect light intensites with their metasoma though I doubt it has much to do with the size of the metasoma.

 

[Nazgul]

Hi,

mimese is a special biological term in german. Yes, it describes the camouflage effect some animals developed. But what´s the exact english term for it, is it really just camouflage?

In the mentioned paper it´s concluded the metasoma may be some kind of antenna-like chemoceptory device in some species (probabely of the genera Microbuthus, Butheolus, Orthochirus and Karasbergia).

Greetings
Alex

Edit: Ha, I found the term in English, it´s mimesis . Do you have a full citation of this paper, Oliver? I don´t know it but it sounds interesting.

 

[mactans]

Fascinating articles, thanks for presenting them. The enlarged cauda of Androctonus and Parabuthus definitely serves purposes. A popular old one, is it serves a dual role for batting enemies, delivering a most painful strike behind a venomous aculeus.

Take for instance Centruroides and their metasomas or Hadogenes, obviously well adapted for crevices and small passageways. Especially the Centruroides as they lay their metasomas to the side. Also offers a means to deliver a sting when there is not alot of space offered or circumstances are cramped.

 

[fusion121]

hi I've uploaded the paper here: ARTICLE
Sensory aparatus is definitely one of the most interesting areas of scorpion research.

 

[Nazgul]

Hi,

thanks a lot for this paper, it´s amazingly interesting. Do you know more publications on this? It should have been researched further.

Greetings
Alex