Sunday 16 November 2014

Lampshade Spider

Image: Ryan Kaldari
At last! Spiders who use their silk to make useful, household objects! Someday we'll be able to go to IKEA and instead of taking home an annoying flat pack bookcase to assemble, it'll just be a box of trained spiders.

Whatever you buy... SPIDERS!

Image: Marshal Hedin
Building a web
The Lampshade variety are a mere 12 species belonging to the family Hypochilidae. They're split into two genera:

The two species within Ectatosticta are found in China...

Image: Marshal Hedin
Sitting in a web
While the ten species in Hypochilus come from the United States.

The American ones are further split into three groups, the ones from the Appalachian Mountains in the east, the ones from the Rocky Mountains in the west and the ones from the California Mountains. In California. They didn't need to think too hard about that last one.

Image: Marshal Hedin
Catching a harvestman in a web
As you may have gathered, Lampshade Spiders quite like mountains. They live on bare rock, often on cliffs overhanging rivers or in the mouth of caves. Even though caves are dark, they only have lampshades. No lamps.

The lampshade in question is their web.

Image: squamatologist
Look at them from above and you see a flattened spider, long legs sprawled as they clutch the circle of webbing that surrounds them.

Image: Jonathan Coddington
Look from the side and you can see how the walls of the web rise up around them and get wider and wider in the shape of a lampshade. With this web the spider can catch all sorts of flying and crawling prey which it will carry back to the centre of the web, consume and then throw out the empty husks.

At the appropriate time of year, males will go through their final moult and give up on eating. Each male heroically leaves the confines of his Cage of Feasting and marches forth in search of a mate.

When he discovers a promising belle cooped up in her own cage, he politely taps the walls to make his presence known. If she's resolutely uninterested she may leap out and chase him away. If not, he continues his tapping and draws closer until he's confident enough to enter her silken abode.

They copulate in the lampshade. Now the male will assume a guarding posture and rest nearby...

Video: caverdaveeee

Because you never know when some other fellow may come along with his toes tapping.

The female lays her eggs and when they hatch, the young spiderlings seem to just wander away to build their own, tiny lampshades. In many other species, the young spiders can release a length of silk into the air and let the wind whisk them away to new, far flung adventures. Lampshade Spiders appear to rely on sheer walking.

They're on a kind of housing ladder. They build their web, feed, grow and then walk away to find a place to build a new, bigger web.

Image: Marshal Hedin
Serious camouflage
They can't wander too far, though. And it's not just because they like the feel of stone beneath their feet.

You may remember that spiders are split into two really big groups: the Mygalomorphs, which includes tarantulas and other beefcakes, and the Araneomorphs, which are all the really good web-spinners. There's also Mesothelae, but they're like some old janitor everyone keeps forgetting about. If you're ever in the corner of the office whispering with your co-workers about how to murder the boss and get away with it, don't forget that the guy emptying the bins is a real, live human with ears.

There are two big differences between the two main groups. One is in the fangs; Mygalomorph fangs point straight down and back, while in the Araneomorphs they point towards each other. The second difference involves breathing. Mygalomorphs breathe using two pairs of internal structures called book lungs. Araneomorphs, on the other hand, have only one pair and sometimes a long, branching tube to go with it.

Image: Marshal Hedin
Lampshade Spiders are oddly in between. They're placed with all the other web-spinners in Araneomorphae, but they're kind of separate from all the others. In fact, you could say there are two kinds of Araneomorph, Lampshades and proper ones.

The thing is, while they have fangs that point toward each other as in other web-spinners, they also have two pairs of book lungs like a Mygalomorph. Book lungs are quite inefficient, which is why tarantulas and the like tend to live in moist, tropical habitats and the ones that live in dryer areas spend most of their time in burrows. Araneomorphs, with their snazzy, branching tubes can survive habitats the tarantula types simply can not.

Image: kestrel360
Thus, with their comparatively inefficient book lungs, it's no wonder Lampshade Spiders prefer to live in the moist surroundings of caves and cliffs that are near rivers. If one got into your house, it would probably head straight to the bathroom and stay there.

Who knows, maybe you'll get a nice, silky toilet seat cover out of it?


Porakiya said...

pretty nifty spiders. and were those hooked pedipalps(spell check?) that I saw in the video? o_O

TexWisGirl said...

handy spideys. :)

Joseph JG said...

@Porakiya Draekojin: They do look hooked don't they? I don't know, those things are supposed to be used in copulation so I hope not!

@TexWisGirl: They'll change the world one day!

Crunchy said...

That Coddington picture is wonderful.

You know, I bet if you could glue an LED to a Lampshade Spider's back, they actually could serve as a little lamp. Just if you reach to turn it off it'll bite you, so... maybe not a great lamp after all.

Joseph JG said...

That one picture is fantastic. I'd love to see the shadows it would cast!

You know, I think a lamp that bites you when you try to turn it off could be a pretty cool study aid.

Crunchy said...

When you put it that way, there just might be a market for that. Also it'll catch annoying flies for you! Sold!

Joseph JG said...

You just never know where the next big thing will come from!

Unknown said...

I enjoyed your characterization of Mesothelae as the janitor people ignore into anonymity. I enjoyed this post on Lampshade Spiders.