Why are arachnids, and tarantulas in particular, so fascinating?

Honestly I am not sure why I am so drawn to them.  I like to think I am able to find something to like about every aspect of God's creation, but for some reason I really find spiders and their kin most fascinating.

The reasons are many and varied.  For example, motion... tarantulas (spiders and other arachnids - but I will tend to focus on tarantulas here) have ONLY flexor muscle attachments in their limbs.  That means that using muscular contraction spiders can only bend their legs inward (they have multiple types at the attachment points to move legs forward / backward in range).  So how do tarantulas extend their legs?  Blood pressure.  They literally use a hydraulic system; they force blood / fluids into the legs under pressure which extends them.  Pretty cool!  Another example is how they feed.  Tarantulas cannot ingest solids.  They literally have filters around their mouth and in their hard esophagus that prevent particulates from entering their stomach and intestines.  So how do spiders eat?  Well, they basically masticate (chew) their prey while regurgitating digestive fluids onto it.  They create a nutrient-filled, gooey mash which they then suck on with their little vacuum-like mouth.  How do they suck it up?  They don't have cheeks or tongues like we do.  They have a special "device" that is part of their stomach called a "sucking (or pumping) stomach".  It works both ways, it can eject fluids from the spider or suck them into the spider.  They have internal cheeks.  Pretty smart.

Speaking of smart, tarantulas have relatively large brains but what I think is most interesting is the shape of their brains.  Tarantula brains are torus shaped... a donut.  The size is necessary to be able to accept sensory input from all the sensory organs all over the spider as well as control the legs and in some spiders with good vision, to be able to judge depth and distances and identify potential prey.

Finally (for now) something that always amazes is me is the fact that the esophagus and sucking stomach run right through the hole in the brain and are part of the exoskeleton.  This means when a spider molts, the esophagus and stomach are pulled out of the body and left with the rest of the exoskeleton.  You can see them clearly in larger tarantula molts.

A couple other, minor factoids...  one of the primary waste elements in spider poo is the same chemical that provides the reflective part of dog and cat eyes (when they shine at night if you point a flashlight at them).  Also, not ALL spiders are venemous... there are actually at least two know species that do not have venom.  Most do have venom, but in general, spider venom is designed to disable their prey and has little effect (can you say no worse than a bee sting?) on humans and other mammals, assuming they actually do inject you during a bite (venom is precious, they don't want to waste it).

Hope you enjoyed my little spider rant.  :)

Long time, no post.

I've been a bit reclusive and not overt the past few weeks.

I have mostly been working, playing games, doing some geocaching with my wife and family. Quiet, less social stuff. Well I guess geocaching with the entire family is sort of social. :)

I am traveling to Boston the week of the 22nd for work. Next week kids have off for Spring break.

That's about it! I have a few Tarantulas that had better molt soon or they will explode. My GBB molted and is getting too big for her current cage.

Sorry to be so boring!

I did attend a seminar which was basically about how we got our [modern/English] Bible. That was interesting. Some of the speakers were good (a couple of archeologists were excellent), some of them were not so good - their presentations turned into sermons. I was disappointed that they did not include a section on the separation of church and state in America, but all in all it was worth the price of admission (free - accommodations paid for by a large donation).