Spikes on tarantulas.

[basin79]

I was getting some pics of some of my tarantulas just now. Going through them I saw my Pamphobeteus sp Costa had leg spikes and spikes on her palps too. Now if I'd have noticed them I'd have taken pics of them so these cropped pics are the best I've got.

Now I knew Megaphobema robustum had defensive leg spikes but thought they where unique. What exactly are these?

 

[Greasylake]

There's another species from south America that has spikes on the undersides of its legs. I can't remember exactly what species it is, extremely rare in the hobby though.

 

[basin79]

There's another species from south America that has spikes on the undersides of its legs. I can't remember exactly what species it is, extremely rare in the hobby though.

So what's the deal with my lass? Are Pamphobeteus known to have leg spikes? To be honest I haven't been able to get a clear look at my juvenile Pamphobeteus antinous as she is very shy.

 

[Venom1080]

@Philth You've seen obese tarantulas with leg spikes puncture their abdomens while kicking hair, correct?

 

[basin79]

@Philth You've seen obese tarantulas with leg spikes puncture their abdomens while kicking hair, correct?

So many species have spikes? I could understand them on the legs but on the palps?

 

[Venom1080]

So many species have spikes? I could understand them on the legs but on the palps?

No, very few tmk. Couldn't tell you, sorry.

 

[Greasylake]

So what's the deal with my lass? Are Pamphobeteus known to have leg spikes?

This I do not know. I don't have any Pamphos big enough for me to check and I only have one so my sample size would be too small to be of any use.

 

[KezyGLA]

There are many species with these spines/spikes. Megaphobema robustum, Stichoplastoris sp., Crypsidromus sp. etc.

I think have seen them on Xenesthis and a few Pamphos too

 

[basin79]

There are many species with these spines/spikes. Megaphobema robustum, Stichoplastoris sp., Crypsidromus sp. etc.

I think have seen them on Xenesthis and a few Pamphos too

Cheers. I've looked back on previous pics of this lass and of course they're present. Can't believe I've only just noticed them. Also I'm surprised more haven't been surprised to find spikes on their tarantulas.

So what's the deal with them? Defensive? Why on the palps? Is it a case of nature knows best and no one knows?

 

[Clareesi]

So what's the deal with my lass? Are Pamphobeteus known to have leg spikes? To be honest I haven't been able to get a clear look at my juvenile Pamphobeteus antinous as she is very shy.

I looked at my pamphobeteus platyomma and see if either my male or female had them and I couldnt see any.

 

[basin79]

I looked at my pamphobeteus platyomma and see if either my male or female had them and I couldnt see any.

I'll have to see if I can get some pics of my antinous.

 

[Vanessa]

Tone Killick posted about that just today on The Silk Road on Faceboook.

"Spines are strong, thick, mechano-sensitive, modified leg hairs which are triple innervated, which means they are supplied by three nerves. They have the same triple innervation as smaller tactile hairs. Spines can be moved hydraulically and can be “switched” on and off by the spider’s hemolymph (blood) pressure. When the hemolymph pressure in a leg increases, the leg spines become “switched on”, erect and become sensitive to impulses from their three nerves. When the spider is at rest and hemolymph pressure returns to normal, the spines return to the flat resting position and no nerve impulses can be recorded. In addition to their sensory functions, leg spines might therefore act as hemolymph (hemostatic) pressure receptors."

 

[basin79]

Tone Killick posted about that just today on The Silk Road on Faceboook.

"Spines are strong, thick, mechano-sensitive, modified leg hairs which are triple innervated, which means they are supplied by three nerves. They have the same triple innervation as smaller tactile hairs. Spines can be moved hydraulically and can be “switched” on and off by the spider’s hemolymph (blood) pressure. When the hemolymph pressure in a leg increases, the leg spines become “switched on”, erect and become sensitive to impulses from their three nerves. When the spider is at rest and hemolymph pressure returns to normal, the spines return to the flat resting position and no nerve impulses can be recorded. In addition to their sensory functions, leg spines might therefore act as hemolymph (hemostatic) pressure receptors."

Absolutely fantastic. Thank you.

 

[Clareesi]

Tone Killick posted about that just today on The Silk Road on Faceboook.

"Spines are strong, thick, mechano-sensitive, modified leg hairs which are triple innervated, which means they are supplied by three nerves. They have the same triple innervation as smaller tactile hairs. Spines can be moved hydraulically and can be “switched” on and off by the spider’s hemolymph (blood) pressure. When the hemolymph pressure in a leg increases, the leg spines become “switched on”, erect and become sensitive to impulses from their three nerves. When the spider is at rest and hemolymph pressure returns to normal, the spines return to the flat resting position and no nerve impulses can be recorded. In addition to their sensory functions, leg spines might therefore act as hemolymph (hemostatic) pressure receptors."

Oh that's just really cool

 

[Vanessa]

Out of the species that I have, the most obvious spikes I have ever seen have been on my Hapalopus sp. Colombia Large.
Even more obvious than my adult female, is my mature male. Maybe because much of his regular setae has been rubbed away and the spiny setae are far more obvious, or maybe it has something to do with him being mature. Either way, there is no need to crop this photo down... they're practically poking your eyes out.

 

[Moakmeister]

Out of the species that I have, the most obvious spikes I have ever seen have been on my Hapalopus sp. Colombia Large.
Even more obvious than my adult female, is my mature male. Maybe because much of his regular setae has been rubbed away and the spiny setae are far more obvious, or maybe it has something to do with him being mature. Either way, there is no need to crop this photo down... they're practically poking your eyes out.
View attachment 300150

Can they accidentally slice open their own abdomen with those spines?

 

[WolfSoon]

I’ve noticed these on my Bumba cabocla female. It’s exciting to know how they function!
Forgive my subpar photography skills

 

[Vanessa]

I’ve noticed these on my Bumba cabocla female. It’s exciting to know how they function!

Mine isn't large enough to see on her yet, but I will keep my eyes open for them. They are tougher to see on the darker species, because they seem to always be black... regardless of the overall colouring of the tarantula.

 

[WolfSoon]

Mine isn't large enough to see on her yet, but I will keep my eyes open for them. They are tougher to see on the darker species, because they seem to always be black... regardless of the overall colouring of the tarantula.

That’s interesting! I wonder if it’s the same with true spiders. I’m seeing spines everywhere now in macro spider photos. So far they’re all black.
I think they’re easy to spot on B. cabocla (a larger specimen) since they have those otherwise sleek, spindly legs.

 

[z32upgrader]

My P. fortis has a bunch of nice downward-facing spikes on her metatarsus as well as pedipalps and front legs. Metatarsal spikes are much more numerous than anywhere else on her.
On the molt, the spikes are very easily seen when backlit.