Tarantula documentary.

[skinheaddave]

Just caught a tarantula documentary on the Discovery Channel. Don't know if you'll get the same shows down there, but if you don't, consider yourself lucky. It was kind of fun to watch, but there were some questionable comments. Most were harmless enough, some were downright misleading. The two that made me laugh the most, however were:

1] They are talking about a H.lividum. They then say that "nearby," two scorpions are having a pushing match. The two scorpions are, of course, P.imperator. They look like they might be getting ready to breed, though they haven't quite sorted out chela positions yet. Does make you wonder what they meant when they said "nearby," though.

2] Apparently, vipers and tarantulas share the "same outdated fangs." I almost spit out my ginger beer when I saw that one.

Cheers,
Dave

 

[JacenBeers]

What is the true diffference in their fangs?

 

[MrT]

SHD,
What do you think they were implying by saying: "same outdated fangs"

 

[Vys]

I don't understand this either..normally, I'd do a bit of research on the net..but seeing as how I've reached rock bottom on my internetquota (well, 1 meg to go ) I'm just gonna say that I don't see any resemblance between viper fangs and tarantula fangs other than that they both go down..

 

[conipto]

In regard to outdated fangs, I would imagine they are comparing them to true spiders, which to my understanding are more evolved.

Bill

 

[Code Monkey]

The primitive versus modern fang arangement is a bit of b.s. imo. The argument goes something along the lines of comparing the opposing fang arrangement of true spiders to our opposable thumbs, i.e. you can get penetrating leverage without using the body - big whoopin deal. As anyone who has observed their Ts feed can attest to, their body is the leverage, the large fangs hook into the prey and it is pulled into the body giving quite efficient and deadly results.

Similar situation for the viper: it's goal is to capture whatever it's biting, defensive bites being a last resort. Which would work better, backwards curved fangs which prevent the prey from escaping and work in tandem with the rest of the snake's backwards curved teeth while poison is administered, or opposable fangs which would require far more muscular pressure to hold the prey?

It's a silly idea to assume that more recent equals improved in evolution. In fact, that's one of the biggest misconceptions about evolution, that things improve. Things simply adapt. True spiders have a fang arrangement that makes sense for living in delicate webs and small bodies. Tarantulas have a fang arrangement that makes sense for having a large, strong body and hunting in primarily stable terrestrial or tube webs. Each is well adapted for the niche they evolved to thrive in.

 

[skinheaddave]

Well, both T fangs and viper fangs are hollow, have the venom forced out by muscular action and are articulated. I don't know about the spider world, but in the snake world, vipers have the most highly advanced venom delivery system. Also, it doesn't strike me that either vipers or Ts have a hard time of life because their fangs are somehow substandard. If they were truly substandard, something else would have evolved or the whole family would have gone extinct by now.

Cheers,
Dave

 

[conipto]

Originally posted by Code Monkey
True spiders have a fang arrangement that makes sense for living in delicate webs and small bodies. Tarantulas have a fang arrangement that makes sense for having a large, strong body and hunting in primarily stable terrestrial or tube webs. Each is well adapted for the niche they evolved to thrive in.

That's a good way of explaining it, and I have to mention I agree and realize all of that... However, I was just saying that's what the geniuses at Discovery Channel probably meant...

 

[Code Monkey]

Originally posted by conipto
However, I was just saying that's what the geniuses at Discovery Channel probably meant...

I knew what you were getting at, I just saw at an opportunity to do my usual Cliff Claven impression It's just funny how the first thought that pops into a naturalist's head hundreds of years ago still stays stuck in popular knowledge. Someone decides that true spiders must have the better fang arrangement, and everybody else, even the snakes it seems, get panned for having parallel action

 

[skinheaddave]

The thing that gets me is that I have yet to see a decent snake documentary that didn't go into how marvelous the viper fangs are. It seems that snake people can at least appreciate verticaly articulated fangs.

Anyhow, good points C-M.

Cheers,
Dave

 

[Wade]

About the emperor scorpions being "nearby", this is typical...

I saw annother Discovery Channel documentary where they showed a desert Brachypelma sp. with an eggsac. When the slings dispursed, they wanted to illustrate the long odds against survival, by showing them being eaten by various predators. These predators included an amazonian frog (probably thousands of miles away from the Mexican desert!) and a old-world cameleon (other side of the world!). Boy, those little slings sure got around!

I realize that it's necessary to artificially set up many senarios in order to capture them on film, but it seems that they could AT LEAST try to do it accurately!

Wade