Leap in conte crayon

This week's Illustration Friday prompt is sight. And it might seem a bit of a stretch for even an arachnophile (hey, if there are 'phobes it stands to reason that there are 'philes as well, right?) like me to be able to use a spider for the word sight, but it'll make sense if you bear with me.

It's true that most spiders don't have very good vision. For your average orb weaver sitting and waiting in a web for the tell-tale vibrations of a trapped bug, there's really not much need for sight. Not all spiders are web hunters, though.

As their name suggests, the Jumping Spiders (Salticidae) hunt by jumping at their prey. They'll sneak up as close as they can without disturbing an insect, attach a safety-line of silk in case they miss, and then literally take a flying leap onto their dinner.

It's not a blind leap, either. Jumping spiders have some of the best sight of any invertebrate group. You have to, if you're going to be accurate enough in your jumping to survive. It leads to some interesting interactions with their environment, as well. Jumping spiders tend to act as though they're interested in what's going on around them (they probably are...) and will often inconveniently turn around to face the camera lens when a nerd like me is trying to get a good shot of them. It can be fun, though, too. I've been known to tease the tiny Zebra Jumpers that occasionally show up in the office with the tip of my pen. Who says you can't play with spiders?

For anyone who's not phobic, there's some pretty neat footage of a hunting jumping spider here. Get a load of those eyes.

----------

This sketch is pretty loose and scribbly, but it's not bad considering that I'm still getting over a wrist sprain. Do you have any idea how often we use our wrists in a day? I certainly do after these past few weeks. I might have liked to have added a bit more detail in the picture, but things started getting a little wobbly so I thought I'd better put the brace back on. Things are coming along, though. Maybe next week I'll even get brave enough to pick up a pen instead of a crayon.

Lichen in art stix

This week's Illustration Friday prompt is hitched, and there are few more things in the world more "hitched" than the components of your average lichen.

Lichens are associations between algae (or cyanobacteria as well) and fungi. The blanket term for long-term close association and interaction between two species is symbiosis, and if I remember right it was originally coined specifically to describe how an alga and fungus work together as a lichen. This particular brand of symbiosis used to be taught as the prime example of what's called mutualism, where both organisms benefit from the association and sometimes can't even exist without it. If I was going to call a lichen a mutualistic association I'd explain it by saying that without the alga the fungus wouldn't survive because it can't make its own food, and without the fungus the alga wouldn't survive because it would desiccate.

You'll notice that I said if I was going to call this mutualistic. Thoughts on that changed a number of years ago in the scientific community. Now some scientists prefer to call it commensalism, where one partner benefits and the other isn't harmed. Sort of a marriage of indifference, I guess. Some scientists have even gone so far as to call the association a form of parasitism by the fungus, although I think that's a bit extreme.

Me? I just figure that the two organisms are pretty permanently hitched.

What you're seeing in today's scribble is a loose (very... see below) interpretation of some SEM views of lichens that I found on the web. The green blobs would be algae, and the brown... things are the fungal hyphae surrounding them. And the reason why it's so scribbly when I usually like working on details?

Yeah, I'm still splinted up. Turns out that the sprain was a little less minor than I thought it was.

Ah well.

Scribbles for the near future then, I guess. Probably good for me, in the end. It doesn't hurt to loosen up a bit now and then, even if it's not something you're exactly choosing.

I suppose.