Spider silk

It’s awesome stuff, as this video explains.

Also recommended if you want to learn more: this book, Spider Silk: Evolution and 400 Million Years of Spinning, Waiting, Snagging, and Mating. There’s so much coolness in spider biology, I’m tempted to offer an elective in the subject…except that I think it might be too narrowly focused for our curriculum, and about half the students would refuse to go anywhere near it.

I maked a video

I’ve been naughty. I haven’t been keeping up with my intended schedule of one video per week. But finally I got something done.

There have been lots of distractions, but honestly? This is tough for me. There are days I don’t want to look at my face or hear my voice, and making these videos compels me to sit down and wrestle with my lack of charisma. I’ll keep plodding along, mainly as therapy — I do enjoy the process, it’s just that final step of subjecting it to the eyeballs of the world that is hard.

Trying to figure out why this spider appeals to me

I think it’s the idea of living in your home for 16 years and never leaving it except for brief forays to leap out, kill, and eat passers-by.

I still have questions, though. What about sewage? How do they clean up the spider poop that accumulates? Also, they show a spiderling … are males more prone to wandering from home? How do they avoid getting eaten when they tap on the turret door?

Spider update

First, the bad news. I now have no adult males, because Xena ate her consort, as I feared she would. I am beginning to suspect that she’s one of those radical feminist lesbian spiders who is going to kill every male she encounters. I don’t know if they successfully mated before the murder, and she hasn’t yet produced an egg case.

Also, one of my second generation spiders, a young female, abruptly died. Before she curled up and expired, though, she did produce an egg case, so maybe her line will live on.

The good news is that right now I am keeping an eye on three egg cases. The next few weeks will tell if can keep any spiderlings alive any more.

Bad day in the lab

The good news: I’m getting roughly one new egg sac every week, so I’ve had one produced on 27 December, another on 4 January, and another this week, on 7 January. I can make progress with that level of production.

Except the bad news: that egg sac from December should have hatched out by now. I opened it up: mostly dead. There were a total of 35 eggs in it; 6 had made it to the postembryo stage, and then died; 4 had made it past the first instar, and then croaked; 24 were arrested in an earlier embryonic stage, and were clearly not going to make it any further. There was ONE second instar survivor, waving its legs weakly in the midst of the charnel house of its siblings. That’s not very good. I’m not even certain the survivor is going to make it — I put it in a little chamber of its own with a fruit fly it can try to eat.

The other egg sacs…well, I’ll have to wait and see. I isolated the one from 4 January, and like the December clutch, put it in a petri dish on a cotton pad, which I spritz with water daily. Unfortunately, I’m finding that the pad doesn’t seem to help, acting more as a dessicant, I think. So I threw out the cotton on that second clutch. I’m leaving the 7 Jan sac with its mommy, in a large vial. We’ll compare outcomes under those two conditions.

Another hypothesis for this problem is that my original wild caught stock produced vigorous clutches of spiderlings, where the majority were healthy and fine…and cannibalistic, which contributed to a rapid culling. All of the egg sacs recently have been the product of inbreeding between progeny of the extraordinarily fecund Gwyneth. So I’ve placed my sole remaining male, a son of Gwyneth, in the company of a daughter of Xena, and will, I hope, get a new outbred clutch to compare. Or maybe Xena1 will consume the puny male. It was tough to get Xena0 to put up with any mates at all.

It would be interesting if Parasteatoda were sensitive to genetic inbreeding, rather than this low output being a result of my poor spider husbandry skills. I’m so used to zebrafish and flies that don’t care if you cross an individual with its sibling, its offspring, its parents, its grandparents (The Aristocrats!), but it is possible that wild species that engage in more mixing might be carrying a higher load of recessive lethals…although I’d also think there’d be limits to how much mixing there’d be in a synanthropic species with limited mobility in adults. Maybe there’s a lot of juvenile ballooning going on that I’ve missed? I’ll have to keep my eyes open in the spring, and see how my garage gets repopulated.

I’ve also noticed something strange going on in my brain. The questions I’ve been asking myself have been shifting from the generally embryological to something more ecological — I might turn into an eco-devo guy yet.

Spider update: I peeked

Just a little bit. I tore open a tiny corner of the one egg sac I have right now, and it looks like a batch of fine healthy eggs, and then I quickly folded the bit of sac over it and restored it to the incubator. I’ve been maintaining moderate humidity for it, and it seems to be working.

Otherwise, while I’ve been waiting for the spiders to reproduce, I’ve been cleaning up my lab fairly thoroughly. I threw out stuff from 15 years ago today, and the benchtops are looking tidy, and I washed a mass of dirty glassware. I’ll have to give everyone a video tour once I’m done. It’s been surprisingly pleasant doing mundane tasks around the lab space lately.

End-of-year spider report

Quick update, nothing exciting. The colony has been cleaned up and fed, I’ve got an egg case made on 27 December that I am not touching at all, other than to move it to chamber that I’m maintaining at a constant temperature and moderate humidity. With any luck, I’ll have spiderlings by the end of the week.

I’m still hanging on tenterhooks, though. I’m down to ONE (1) male, who gets rotated around to each of the vials (except to Vera’s — she’s a male-eater). I’m hoping a) he doesn’t get eaten, and b) I get a viable egg sac, otherwise I’m not going to have any embryos until the weather warms up and I can find new spiders around town. To get a sustainable colony, I’m thinking I have to get up to around 50ish adults, which is easily doable.