Avicularia morphotype identification

RHawk

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0.1 Avicularia variegata morph 1 - ex sp. Amazonica ‘Manaus’.. the real bicegoi?
 

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RHawk

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Avicularia rufa.. also has a pretty big range across South America, across Brazil, Bolivia, Peru, and according to the map in the revision, even as far as Ecuador. Like A. avicularia, rufa has back legs roughly 10% longer than the front legs - that can distinguish them from juruensis and variegata when at a small size... of course they have vibrant yellow banding above the tarsi, and they have the pink bangs at the end of the tarsi. They have a very grizzled appearance and get pretty large (mature males can get to be 6.5-7” DLS. Once misidentified as A. juruensis
 

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DaveM

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Thank you very much for this excellent information, @RHawk 👍

Ok, so I have a dumb evolution question. How did some A. avics get to be on Trinidad and Tobago when all the rest are from South America? Did they float there on driftwood and just set up shop? Or were the islands once part of the mainland South American continent millions of years ago and over time they just separated with all the flora and fauna that was part of the mainland?
That's a great question, very interesting to me. Today, it's only about 10 km from Trinidad to the mainland, and about 33 km from Trinidad to Tobago. The waters that separate these islands from the mainland are shallow enough that there would have been land bridges during ice ages, when the sea level was much lower (due to much more of the world's water being locked up frozen as ice at the poles). The most likely explanation is that ancient Avicularia populations expanded across the land bridges, then were separated as the sea level rose and cut off these islands. Then the separate populations evolving independently became different species through allopatric (allo = other, patric = fatherland) speciation.
This is also the currently accepted view of how ancient tarantulas got to Australia from Asia.

There are other less likely possibilities, such as a hurricane uprooting an Avicularia-populated tree that floated some distance across the sea water. I think I read somewhere about one known example of some trapdoor spider species from South Africa having become established in Australia having floated long-distance across the ocean (amazing! but this must be very rare, and is a much less probable way for tarantulas to move between land masses, especially at that distance). Rainer Foelix notes, in his excellent text, that the spiders populating Madagascar are very different from those in nearby Africa, and that no tarantulas from Australia are populating the barrier reef islands.

There are many questions about the evolution of these Avicularia and other tarantula species, how long ago they diverged from one another, what is more closely related to what, whether certain genera are justifiably separate from an evolutionary standpoint. I've read comments on AB that tarantulas have been evolving for many hundreds of millions of years. Not quite true, not many hundreds, but maybe one hundred million years. Most of the species we have are separated by much less evolutionary time than that. DNA sequences from many Theraphosid species are becoming available now. I'm salivating in excitement. I've been thinking about doing some focused sequence analyses to post here on AB, geared toward answering specific questions, if that would be of interest. I do this kind of thing for my profession and as a hobby, but I can write in ways that anyone would understand. With the wealth of knowledge here on AB, in the scientific literature, and now with DNA, we're really going to be able to sort out many of these messes held over from the past.
 
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Marlana

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Thank you very much for this excellent information, @RHawk 👍



That's a great question, very interesting to me. Today, it's only about 10 km from Trinidad to the mainland, and about 33 km from Trinidad to Tobago. The waters that separate these islands from the mainland are shallow enough that there would have been land bridges during ice ages, when the sea level was much lower (due to much more of the world's water being locked up frozen as ice at the poles). The most likely explanation is that ancient Avicularia populations expanded across the land bridges, then were separated as the sea level rose and cut off these islands. Then the separate populations evolving independently became different species through allopatric (allo = other, patric = fatherland) speciation.
This is also the currently accepted view of how ancient tarantulas got to Australia from Asia.

There are other less likely possibilities, such as a hurricane uprooting an Avicularia-populated tree that floated some distance across the sea water. I think I read somewhere about one known example of some trapdoor spider species from South Africa having become established in Australia having floated long-distance across the ocean (amazing! but this must be very rare, and is a much less probable way for tarantulas to move between land masses, especially at that distance). Rainer Foelix notes, in his excellent text, that the spiders populating Madagascar are very different from those in nearby Africa, and that no tarantulas from Australia are populating the barrier reef islands.

There are many questions about the evolution of these Avicularia and other tarantula species, how long ago they diverged from one another, what is more closely related to what, whether certain genera are justifiably separate from an evolutionary standpoint. I've read comments on AB that tarantulas have been evolving for many hundreds of millions of years. Not quite true, not many hundreds, but maybe one hundred million years. Most of the species we have are separated by much less evolutionary time than that. DNA sequences from many Theraphosid species are becoming available now. I'm salivating in excitement. I've been thinking about doing some focused sequence analyses to post here on AB, geared toward answering specific questions, if that would be of interest. I do this kind of thing for my profession and as a hobby, but I can write in ways that anyone would understand. With the wealth of knowledge here on AB, in the scientific literature, and now with DNA, we're really going to be able to sort out many of these messes held over from the past.
I would definitely be interested! It’s one of my annoyances with keeping arachnids, I have so many unanswered questions.
 

CEC

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Avicularia variegata M#1
(Manaus, Brazil)

Sling .5"
FB_IMG_1536499812817.jpg

Sling .75" FB_IMG_1476747652114.jpg

Sling 1"
FB_IMG_1536499799282.jpg

Juvenile 1.5"
FB_IMG_1536499792735.jpg

Juvenile 2"
FB_IMG_1536499782846.jpg

Sub-Adult 3"
FB_IMG_1536499775411.jpg

Pen-Ultimate Male 4"
FB_IMG_1577508958663.jpg

Female 4"
FB_IMG_1544352817685.jpg

Mature Male 6"
IMG_20200625_050309_780.jpg

Mature Female 6"
20200515_024318.jpg
 

Matt Man

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so glad I used the search function. Thanks all this is an awesome thread
 
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