Interesting read

tyrantuladub

Arachnosquire
Joined
Feb 3, 2013
Messages
100
Well, seeing as the hairs are connected to nerves that are very sensitive to vibrations, and seeing that sound is nothing more than a series of vibrations, I could buy it to a degree haha. The sensitivity to the sub-bass to midrange (by human standards) is also quite intriguing. I could go on to list hundreds of music production analogies and how they correspond to my music but I've come to the general consensus that based on this article, and to put it rather bluntly, they're extremely sensitive to my Dubstep. I'll keep that in mind and not turn it up very loud haha. Thanks for posting, good read.
 

BaddestRuffest

Arachnosquire
Joined
Mar 10, 2013
Messages
121
Thanks I thought so as well, intriguing what we are constantly learning about our little 8 legged friends. I'm still not whole heartedly convinced on the subject of their eye sight though. How can anything with 8 eyes nestled so closely together have such poor quality eye sight? Then again counter to my own thoughts you have to take into consideration the evolutionary effect and because they "hear" movement so well why do they need to see at all ?
 

Balvala

Arachnosquire
Joined
Jan 10, 2013
Messages
95
Thanks I thought so as well, intriguing what we are constantly learning about our little 8 legged friends. I'm still not whole heartedly convinced on the subject of their eye sight though. How can anything with 8 eyes nestled so closely together have such poor quality eye sight? Then again counter to my own thoughts you have to take into consideration the evolutionary effect and because they "hear" movement so well why do they need to see at all ?
To expound upon the eyesight topic, I'll provide these two posts from the BTS forums as some insight. They both reside within the same thread: http://thebts.co.uk/forums/showthread.php?4465-A-hello-and-a-few-questions!&p=33958#post33958

Phil Rea (Moderator at British Tarantula Society forums) - 13-10-08 said:
It's ocular tubercle

From experiments carried out on the ocelli of Aphonopelma chalcodes by R. Dennis Dahll and A. M. Granda, they could 'see' wavelengths between 350 and 640 nm (which actually includes red) if I remember far enough back to my schooldays
Spectral sensitivities of primary and secondary eyes in the Theraphosid spider, Aphonopelma chalcodes Chamberlin, were investigated by recording intracellular receptor potentials from single photoreceptors. The responses of all cells were graded depolarizations, monophasic in waveform. All cells showed dual spectral sensitivities, with a primary peak near 500 nm and a secondary peak in the near ultraviolet at 370 nm. The 500 nm peaks were fit well by a Dartnall nomogram. Spectral sensitivity curves were similar under both dark and light adaptation suggesting the presence of a single photopigment. Intensity-response functions with white light showed sensitivity differences between primary and secondary eyes. Secondary eyes had greater sensitivity ranges and smaller slope coefficients showing them to be more sensitive than primary eyes.
As well as a second post for clarification:

Phil Rea (Moderator at British Tarantula Society forums) - 13-10-08 said:
Bear in mind that despite the fact that they can theoretically see the wavelengths that comprise red light, it's unlikely that they are very sensitive to it.

They have sensitivity peaks near 500 nm, which would be round about blue/green light, with prominent peaks in the near ultraviolet at 370 nm.

You're right about the learning something new stuff. I'm the same. They never cease to amaze me
Keeping that in mind, you were right in the way that you have to pay attention to the evolutionary traits considered more significant among the rest to refine over a given amount of time. Of course, the species within Theraphosidae differ in development from other spiders or, in a broader sense, other arthropods in general (to a degree.) You have to realize, however, that a tarantula possesses a brain (more of a cluster of neurons, I suppose) with a connected nervous system that is nowhere near developed enough for any acutely refined vision, an ability to reason through detailed circumstances, et cetera... to be present in the way we might perceive them ourselves.

What you would gather from the information above is that, if the relative majority of tarantula are a little more sensitive to direct light, they would obviously be driven to spend more time in darker areas to avoid it or take advantage of less visibility for hunting purposes, et cetera... (which I'm not insulting your knowledge by conveying, I'm merely building up to the conclusion.) This behavior is then presented in various species as evolving aspects for the purpose of survival begin to develop among the entirety of their bodies. It leads to making clear eyesight less of a priority than other senses within a progressively developmental stage taking place over a vast period of time. Once one sense becomes slightly sacrificed, the body's adapted response is to, at a faster pace, more efficiently enhance other sensory organs to better compromise for any imbalance presented: E.g. - the value of more attention given to the primal nature of the creature's survival tactics and additional, habitual traits passed on genetically. [Prior Implication]

You could probably akin this type of development to that of a blind human being who develops other keen senses due to the body's adaptation to compromise for the condition. That isn't a common trait and the adaptation occurs in a relatively short period of time in comparison to the commonality of moderate eyesight in tarantulas and other senses that have had millions of years to develop accurately in a specimen with significantly less, if any at all, sentience. There's so much more to gain knowledge of, though. This is just my consensus based upon observations and some... common sense-analysis through various comparisons evaluated for funsies.

You've all more than likely been aware of this information, though. I'm just informing for the audience that has not. :)

ON TOPIC TO THE ORIGINAL POST::

That was a fairly interesting read. I'm curious as to what the results for their goal research mentioning "prey signals" might end up being, as well.
 
Last edited:

prairiepanda

Arachnoknight
Joined
Sep 12, 2012
Messages
209
Well, seeing as the hairs are connected to nerves that are very sensitive to vibrations, and seeing that sound is nothing more than a series of vibrations, I could buy it to a degree haha. The sensitivity to the sub-bass to midrange (by human standards) is also quite intriguing. I could go on to list hundreds of music production analogies and how they correspond to my music but I've come to the general consensus that based on this article, and to put it rather bluntly, they're extremely sensitive to my Dubstep. I'll keep that in mind and not turn it up very loud haha. Thanks for posting, good read.
Humans perceive sound through hairs also, very similar to how spiders "hear". Our "hearing hairs" are submerged in fluid though, I think. But they get damaged and fall off over time, leaving us unable to hear certain frequencies. Imagine the handicap a spider would have if it were missing half it's hairs!
 

tyrantuladub

Arachnosquire
Joined
Feb 3, 2013
Messages
100
Humans perceive sound through hairs also, very similar to how spiders "hear". Our "hearing hairs" are submerged in fluid though, I think. But they get damaged and fall off over time, leaving us unable to hear certain frequencies. Imagine the handicap a spider would have if it were missing half it's hairs!
That is indeed a scary thought! I guess the best thing I could compare how they perceive what's around them to is echolocation... Without the echo of course. Haha
 
Top