Some stridulating organs (hissy bits)

[KillerJuan77]

I've heard is annoying, and it may be heard 15 feet away

[ben9034]

K, thnx

[Otis Driftwood]

Ornithoctonus sp. Koh Samui

Prolateral maxilla


Retrolateral chelicerae



P. murinus

Prolateral maxilla and trochanter


Retrolateral chelicerae



E. pachypus

Prolateral maxilla and trochanter


Retrolateral chelicerae



P. ornata

Prolateral maxilla


Retrolateral chelicerae



Cyriopagopus sp. blue

Prolateral maxilla


Retrolateral chelicerae

[Wayne]

Great shots as usual. You must be working on a cataloging a library of these ?

[BayLee]

I agree with Wayne, your photos always have the most precise detail. Your work is outstanding. You are hired Otis….lol

[Otis Driftwood]

Thanks , i just do the pics for a couple of forums but maybe if i get enough together i might try and organize them into some sort of library.

[Derrick]

Originally Posted by Wayne

I know this sounds a little far out in right field but I really wonder how much of a difference there is in the sound from species to species.
It also makes wonder if they could identify a like species or ward each other off through (sound) vibrations.
Must be the Nyquil.

I am also very curious about this subject. I hear a "sandpaper-like" sound when my B. Boehmi kicks hairs. People have told me that its not stridulation. The strange thing is that my female B.boehmi works her palps up and down alternating with her hair kicking legs. It isnt very loud but I hear it EVERY time she is disturbed and kicks hairs. It seems high pitched so it may be hard to hear for some. If it isnt stridulation then what is it? She only does it when defensive. That seems quite like stridulation to me. Any clarifying input?

[Otis Driftwood]

Hi Derrick sorry to take so long to answer your question but i was waiting for my boehmei female to moult so i could show you the cause of the sandpaper noise. The answer is yes it is stridulation you are hearing , your spider produces this noise by rubbing together the plumose setae (feather like hair) on the retrolateral (outside) trochanter and femur of its palp with the plumose setae on the prolateral (inside) trochanter and femur of leg 1.

Retrolateral trochanter of palp


Retrolateral femur of palp


Prolateral trochanter of leg 1


Prolateral femur of leg 1

[Wayne]

As usual, nice pics.

[Derrick]

Thanks so much Otis. I really appreciate the great pics. I thought it was stridulation. She does it in defense. Why would the volume of the sound make a difference? Maybe the natural predators of B. boehmi (in the wild) can hear it like a siren for all we know. If that were the case then B. boehmi would have no need to evolve a louder stridulation. Just a thought.

[mexi-lexi]

Whoah! The size of that fang!!!!!!!!! Excellent pictures, i have never seen such clear close-ups. Keep up the good work!

[M.F.Bagaturov]

Hi Otis!

Great pics!!! Thank You very much, should use some on my site I will ask when!
BTW. B. boehmei is reported the most loud of all the Brachy's but still rare case to hear a sound from it.

[Otis Driftwood]

Hi Mikhail

You are more than welcome to use any of my pics for your site.
Actually i have a question you may be able to help me with , i was looking through Pérez-Miles, F., S.M.Lucas, P.I. da Silva Jr., & R. Bertani. 1996. Systemaic revision and cladistic analysis of Theraphosinae yesterday and noticed that according to the data matrix Brachypelma are not supposed to have any trochanteral stridulatory setae yet in the boehmei pics i posted it is quite clearly present. Is my spider a freak or is boehmei an exception to the rule and if so are there any other Brachypelma species with stridulatory setae on their trochanters as i know that the only Brachypelma material examined in that paper was emilia. I just got rid of all my old skins last week as well so i don't have anything to check with myself. Typical lol.

Edit: I have just found an email from you in my junk mail box from over a month ago (it seems Yahoo thinks i want to read spam emails about viagra pills and OES software (whatever that is?) rather than genuine emails ) so don't think i have been ignoring you lol i'll reply tomorrow when i get back from work.

[Derrick]

When I first posted my experiences with my B. Boehmi stridulating, nobody believed me and told me it was not stridulation and basically said I was hearing things. I know what I hear EVERY time she kicks hairs. Now everyone is saying B. Boehmi can stridulate. It doesnt make sense. Im very thankful to OTIS for posting the great pics of the B. Boehmi's stridulating hairs. I think that convinced a lot of people. It re-enforced my belief in the B. Boehmi stridulating. Its just frustrating that I didnt get taken very seriously when I posted that I thought my B. Boehmi was stridulating.

[jeremy]

Originally Posted by Derrick

my B. Boehmi stridulating

I hear you Derrick! My B. smithi stridulates quite strongly (to me) nearly every time she's disturbed and it was pretty hard to for a lot of (online) people to believe it. She's loud enough to make me jump (sounds like flesh on hot metal) every time she does it, even when I know it's coming. I would imagine stridulation wouldn't have to be very loud to warn most mammals that might make a meal of a T. Disturbing a T is almost always a close-range affair anyway. Amazing how many adaptations they have just for communicating with other animals - bright colors, postures, and even sounds.