As I eagerly wait for a fresh delivery of spiders and breeding group of scorpions,(damn my impatience) I thought I would post some photos and info about tarantula mouth parts, as you do.
Spider mouth parts are called chelicerae. I recently cut up an exuviae (resh moult) from a P.regalis and took some photos.
The chelicerae are at the front of the promosoma, just in front of the eyes, highlighted here on this photo of a P.regalis
Here is the right chelicerae, the photo is taken from the inside view using a USB microscope. Actual size 6 or 7 mm ish.
chelicerae have several functions. They hold the fang, contain the venom glands, and hold the spider's cheliceral teeth, which are used for grinding food and in some species for communication.
This photo shoes where the cheliceral teeth are located.
This photo shows the cheliceral teeth more closely.
Some species of spiders, and tarantulas, make a sort of hissing sound by rubbing their cheliceral teeth together, a bit like a grasshopper does with its legs. This is a warning sound and will usually be heard before a defensive bite.
Spiders fangs are very sharp and are used to inject venom, but can also be used to moves rocks or soil arround and sometimes to dig. This hole where the venom is injected through, is a little way up from the tip. So the tip can retain full strength. You can see the hole in this photo here.
I will finish by mentioning some bites are dry, don't contain venom, but they will only bite to eat or for protection. While all spiders contain venom most is harmless to humans.
