urticating hairs on A. versicolor

[Poec54]

Maybe Avics are in transition to losing the urticating hairs altogether. Versicolor, being an island species and isolated, may be on it's own plan, with a different set of circumstances.

Pslamo's and Taps are interesting, because they have no urticating hairs at all, anywhere, and there's been debate for decades amongst taxonomists as to which subfamily they belong in. Some think they're closest to Poecs, others place them in with the Avics, and still others say they don't belong in either. Maybe they'll get their own subfamily one day. If you didn't know where they were native to, the first assumption would be that Psalmo's are Asian. They're very different from the Avic group in a number of ways. But logically, Psalmo's should have some common ancestor with Avics. The Asian arboreals evolved long legs, slender bodies and most are large. Psalmo's followed suit, except not always for size. Why are so many Asian arboreals so large? Why did Avics go in another direction, with most downsizing, and having shorter legs and bulkier bodies? Since Asian/Indonesian rainforests are similar to NW rainforests, why didn't any Asians take the Avic route, since it's been so successful for them? Is there something that makes that undesirable or unsuccessful in the OW? Or maybe there are some yet-to-be-discovered OW arboreals that are Avic-like. There's still a lot we have to figure out.

 

[SuzukiSwift]

My versicolor has kicked hairs before, the bald spot was turquoise in colour just like the carapace. At the time I was very surprised because I didn't know versis could kick hairs like terrestrial Ts so I thought it must have been just me going crazy but now I've seen this thread it seems I'm not, yay lol She just moulted anyway, back to pretty pink

 

[viper69]

My versicolor has kicked hairs before, the bald spot was turquoise in colour just like the carapace. At the time I was very surprised because I didn't know versis could kick hairs like terrestrial Ts so I thought it must have been just me going crazy but now I've seen this thread it seems I'm not, yay lol She just moulted anyway, back to pretty pink

There ability to flick is news to me now. Suzuk, their exoskeleton is turquoise? Do you have a pic of that, I'd love to see that one!

---------- Post added 11-27-2013 at 12:48 AM ----------

Maybe Avics are in transition to losing the urticating hairs altogether. Versicolor, being an island species and isolated, may be on it's own plan, with a different set of circumstances.

Pslamo's and Taps are interesting, because they have no urticating hairs at all, anywhere, and there's been debate for decades amongst taxonomists as to which subfamily they belong in. Some think they're closest to Poecs, others place them in with the Avics, and still others say they don't belong in either. Maybe they'll get their own subfamily one day. If you didn't know where they were native to, the first assumption would be that Psalmo's are Asian. They're very different from the Avic group in a number of ways. But logically, Psalmo's should have some common ancestor with Avics. The Asian arboreals evolved long legs, slender bodies and most are large. Psalmo's followed suit, except not always for size. Why are so many Asian arboreals so large? Why did Avics go in another direction, with most downsizing, and having shorter legs and bulkier bodies? Since Asian/Indonesian rainforests are similar to NW rainforests, why didn't any Asians take the Avic route, since it's been so successful for them? Is there something that makes that undesirable or unsuccessful in the OW? Or maybe there are some yet-to-be-discovered OW arboreals that are Avic-like. There's still a lot we have to figure out.

I've wondered these very questions for a long time. I've always been surprised by the OW arboreals size and more slender morphology vs their NW arboreal cousins which are a bit more stout generally. Alternatively, aside from selection pressures, every once in a great while, nature puts forth morphologies which appear to make no sense out of no where, the classic example being the Burgess Shale fossil record, MAYBE that is what happened with OW vs NW morphologies. Though different, they both worked, I certainly don't know.

 

[Poec54]

I've always been surprised by the OW arboreals size and more slender morphology vs their NW arboreal cousins which are a bit more stout generally. ...every once in a great while, nature puts forth morphologies which appear to make no sense out of no where

Tarantulas have been around for at least 65,000,000 years, and in that time have had ample opportunity for a number of different variations from environmental influences and climate changes. You'd think the Avic design would have been tried at some point in the OW. It's nothing radical. All the OW arboreals I've seen are sleek and long-legged; speed and agility are a priority, as it is with Psalmo's and Taps. Their larger size means their strides are longer, and they can cover greater distance in a shorter time. Or is their greater size to allow them to subdue larger prey? Or is it both? Avics are certainly agile, but their speed is mainly for shorter spurts. Why don't they need to run as far, when the others do? Have they evolved away from the sleek arboreals, or are they more-recent terrestrials evolving towards them? Is not being able to kick hairs an indication of a move from ground to trees? If they came from ancestors that didn't have urticating hairs, is it possible that they're developing them separately (convergent evolution)? Possible, but unlikely, especially considering the time period and geographical range that OW's encompass, that they haven't done this at all. Maybe the Avic group are latecomers to an arboreal lifestyle.

 

[Keith B]

If I were to venture a guess, I would guess that it's cause Avic's being so small, were probably designed to run away while poo'ing, and take wild suicide jumps to escape. Once in the clutches of a predator, the bristles and biting would be a form of last resort. But this is, of course, just me guessing