Serious 'green feet' (and attitude)

ArachnoJoost

Arachnobaron
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My P. murinus in her usual good mood... I'm amazed about the irredescense (sp?) of the footpads, does anyone know what causes this?
 

ArachnoJoost

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And a close-up of one of the footpads, not quite a sharp photo but the colours are beautiful:
 

Longbord1

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got to lov those pads i know what there used for the p irmina has it and so do the pokies its used for scaring like a moth has fake owl eyes on it's wings
 

SpiderTwin

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Nice pics Joost,
I don't remember reading anything on why T's have that coloring. But it's cool to see, all of the Avic's have it also. Hopefully someone can help you with your question, it would be interesting to know the answer.
 

Neo

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Originally posted by ArachnoJoost
My P. murinus in her usual good mood... I'm amazed about the irredescense (sp?) of the footpads, does anyone know what causes this?
Just some ideas I have. I'm full of ideas. Certain stuff certain things eat, are turned into something else. For example, you've seen many plants of many different colors, they all got that from the earth, the nutrients and so on to make that color, because they are meant for it. Certain things that need to make that color, goes to the leg, therefore you got that. A way blood flows to the leg can be another reason why the foot is blue as such. Or even the texture of the skin can be another reason.

I don't know just some crazy ideas.
 

Longbord1

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the color a plant get it called photosynthesis it's not from the ground
 

Neo

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I thought it was particially from the minerals they get from the ground as well as the sun?

Not a plant wiz so sorry.
 

Longbord1

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they use the suns rays and thewater which is semi nutritious ifrom the groungd to produce photosythesis which is how they make food im not a plant person either just a science nerd
 

Paladin

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photosynthesis is the process in which a plant gets energy...i think chloroform (spelling) is what gices it the pigment..correct me if im wrong...
 

Longbord1

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pretty much what i said i think its clorofil but i could be wrong
also most leaves are different colors under neath the green thas why in the fall they turn red yellow etc.
 

Henry Kane

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Originally posted by Paladin
photosynthesis is the process in which a plant gets energy...i think chloroform (spelling) is what gices it the pigment..correct me if im wrong...
LOL! That's chlorophyll. ;)
Chloroform is the stuff the bad guys in movies pour on a rag and place over someone's face to knock them out cold.


Atrax
 

Lostkat

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Re: Re: Serious 'green feet' (and attitude)

Colour of tarantulas is due to the actual chemical properties of the cuticle covering their entire bodies. The chemical properties of the chitin, or cuticle in the footpad area are different to, say, the clear chitin that covers the eye or the orange chitin that makes up the 'hairs', therefore giving these different areas different colours. Colouring on a tarantula is not determined by pigment, as you get with mammals for example. Our hair, eye and skin colour is determined by the presence and/or absence of pigments, which reflect various wavelengths of light to give the impression of a perceived colour. This isn't how it works with tarantulas (possibly insects as a whole, but I'm not sure about that).

My humble opinion:
These pads primarily seem to aid climbing. I make this assumption because both my Avicularia purpurea and versicolor hasn't got them yet as they're too small, they're both absolutely crap at climbing (can't 'stick' to sides and keep falling). My Avicularia geroldi (who has just got them in his last moult), Pokie and P. irminia all have them and are awesome at climbing. The chemical properties of the footpads must first and foremost be to do with adhesion to vertical surfaces.

I've noticed they have tonnes of tiny little grooves in them, which could be one of the properties allowing them better adhesion, just as you see in geckos and tree frogs (which have millions of tiny pads on each toe). When these footpads were first evolved, it could have been pure coincidence that they were a funky iridescent colour. However, those individuals with brighter footpads might have been more able to scare off potential predators by waving their legs at them. This would, in turn, allow the brightest-footed individuals to survive, breed and pass on their genes, giving a directional selection towards bright iridescent foot pads.

So in short, the beautiful footpads may just be an evolutionary result of their intended property, which is adhesion to steep surfaces to aid climbing.

And just for interest, I'll throw in a pic of my sexy-footed P. irminia, because he seems to like showing them off with a worrying regularity :D
 

Lostkat

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Originally posted by Atrax
LOL! That's chlorophyll. ;)
Chloroform is the stuff the bad guys in movies pour on a rag and place over someone's face to knock them out cold.


Atrax
LOL :D That just cracked me up :D


Yes, chrorophyll is one of photosynthetic pigments found in the leaves of plants to give them their green colouring. However, as I've just said, T's colouring is not determined by the presence or absence of pigments. Whilst you may be able to enhance, say a flamingo's colouring by feeding it certain things, there is absolutely nothing you can do to change a T's colour, bar spray painting or dying it (not recommended, they don't like purple rinses, trust me) ;) Colour in a T is genetically programmed and chemically inbuilt into the chitin.
 

Neo

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Hahah he did say chloroform...I wasn't reading it carefully, just skeeming through the sentence.
 

Henry Kane

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I don't think what a T eats has too much to do with color or iridescence.
I checked the Scultz's book and it doesn't say much about it there.
I'll keep checking around though.
I do have 2 theories...it may have something to do with their threat display (warning colors and all...), or possibly something to do with the climbing ability. The bristles that form their scopulae are obviously specialized for this task. I wouldn't doubt that the iridescence is relative to it as well. I'm curious to know if the iridescence is the actual color of the bristles or if it may be a coating of some sort. :?

Atrax
 

nemesis6sic6

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hi

actually you guys are almost right
photosynthesis is divided into two parts light reaction and dark reaction light reaction is the energy of sunlight is captured and used to make energy storing compunds and the dark reactions dont need this because they use some cycle that i dont remember
well any ways. The choloplast is the site of photosynthesis. where the photosynthetic membrane contains clusters of pigment molecules that are able to capture sunlight there are two photosystems in green plants : phototsystem 1 and 2 . the energy traped by the clorophyl in the cells. cholrophyl only absorbs red and blue light wave lengths of light by pigments. thus they refelct the green color because the absorb the other : It absorbs Violet colorwell and blue does not absorb green and yellow but rather reflects it, it does absorb some orange and it absorbs alot of red.
well any ways i think what i just wrote sounded confusing but um yeah. hopefully you'll understand it. I just woke up :(
um yeah it's interesting how they have that underneath color under their legs. My P.Irminia has them and it's fantastic


geo
 

Henry Kane

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Hey Lokstat! Looks like we posted at the same time. LoL!
I agree most with the climbing theory. I'm going to check with a few people to see if any more light can be shed.

By the way, your male irminia, very nice! A bit vain but nice. ;)

Atrax
 

Lostkat

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With regards to the iridescence relating to the grooves OR a coating of some sort, I just found a very interesting abstract about mother of pearl in a species of clam (bear with me.. this is relevent :p ).

They seem to think that the cause of this iridescence by light diffraction. By looking at the iridescent surface of the shell, they noticed that it was covered with tiny grooves. It was found that the higher the density of grooves, and the smoother the groove surface, the more intense the colouring.

Relating back to the T's, this makes sense really. No terrestrial T's I know of have bright footpads. My B. vagans, A. geniculata and B. emilia all have footpads, but they're not gorgeously stunning like my arboreals. It's a possibility that the iridescence is coupled with more numerous grooves, which give a greater ability to climb. Terrestrials don't need to be able to climb, so their foot pads aren't as densely ridged.. it makes sense to me anyway.

Sorry if noone understands this.. I can't put it any simpler :)


Woohoo - just found another article on the colour of butterfly wings about the whole ridges/diffraction mechanism outlined above.
 
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Lostkat

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Originally posted by Atrax
Hey Lokstat! Looks like we posted at the same time. LoL!
I agree most with the climbing theory. I'm going to check with a few people to see if any more light can be shed.

By the way, your male irminia, very nice! A bit vain but nice. ;)

Atrax
Yeah, looks like we're kinda thinking along the same lines. It makes absolute perfect sense to me anyway! I should actually be revising for my uni exams.... but this has got me more interested than 'the complex inner workings of the kidney' ever could :D :D
 

Ultimate Instar

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I'm pretty sure that it's a diffraction effect. Take a look at a DVD or a CD. That's caused by a diffraction grating, i.e. the grooves are lined up next to each and evenly spaced. The reflected light is split up into its component parts, a rainbow effect. My guess is that the hairs on the T's foot pads are very thin and evenly spaced to allow adhesion to slippery surfaces. The hairs reflect some light and the result is a very pretty iridescence. I doubt that it's much of a threat display, just a coincidence related to their ability to climb smooth surfaces.

Karen N.
 
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