A whole lot of chompin’ and sexin’ going on

This is a beautiful video about the arachnids of Uruguay — great videography and information, and some spectacular closeups of spiders in action. They do seem to spend a lot of time murdering insects and sucking them down, and the sex scenes, especially in the sexually dimorphic species, can be graphic and moderately distressing — tiny males scurrying up to the abdomens of huge females, it’s like trying have sex with a wall topped with fangs that can descend when you’re done and kill you.

It’s all still pretty, and now I want to visit South America. I’ve been to Ecuador, but that was before I discovered the wonders of spiders. I should go again, except…damn this legal weight on my shoulders.

I wouldn’t have recognized this spider from last week!

Before I left for the Twin Cities this weekend, I’d fed the spider colony fat juicy waxworms, and they fell upon them furiously. Today I checked on them, and boy were there a lot of bloated, indolent spiders lounging about in their webs, reluctant to even move. One surprise…I took a peek at Yara, who I’ve photographed before, and the change was striking, not just in her size, but in her pigment patterns.

Look how dark she is! This isn’t just the lighting, either — I tinkered a fair bit to get good illumination. Compare it to the previous photo, where she’s much lighter in color, and I would have said she was one of the more lightly pigmented members of the colony. Now I’m wondering how rapidly they can change color and what prompts it, especially since I’ve been following pigment development in the babies.

I was also looking at cobwebs today. There might be some potential for student projects here.

My wife went to Colorado and all I got was… #SpiderSunday

Mary has been away the last few weeks, helping Skatje and Kyle handle a ravening, demanding 15-month old, Iliana. She finally got back home last night, and she brought me a present! It was a spider. No one is surprised.

Well, I was, a little bit. Spiders show so much variation — I’m pretty sure this is Steatoda triangulosa, as it’s obviously a theridiidid, and it’s got that pretty pair of zig-zag stripes down the abdomen, but it’s so golden, and it’s got more zigs than I usually see in S. triangulosa here in Minnesota, and the patterns break up in a messy and different way. Species are so goddamned complicated. Why did I ever leave my nice, inbred, isolated zebrafish?

Anyway, she was guarding a nest in my daughter’s garage, and Mary brought back 6 egg sacs, all of the fluffy type we see with S. triangulosa. Most, probably all, are hatched out, but I’ll find out when I take them into the lab later.

Spidercloth!

I need this:

It’s spidercloth, a single piece of silky fabric made from silk drawn from a million spiders. It might be a little bit labor intensive.

To produce this unique golden cloth, 70 people spent four years collecting golden orb spiders from telephone poles in Madagascar, while another dozen workers carefully extracted about 80 feet of silk filament from each of the arachnids. The resulting 11-foot by 4-foot textile is the only large piece of cloth made from natural spider silk existing in the world today.

So I can’t pick up a spidercloth cloak at Target?

We’re going to have to figure out the chemistry, and we also have to figure out the machinery in spinnerets.

Of course, spending four years to produce a single textile of spider silk isn’t very practical for scientists trying to study the properties of spider silk or companies that want to manufacture the fabric for use as a biomedical scaffold or an alternative to Kevlar armor. Several groups have tried inserting spider genes into bacteria (or even cows and goats) to produce silk, but so far, the attempts have been only moderately successful.

Part of the reason it’s so hard to generate spider silk in the lab is that it starts out as a liquid protein that’s produced by a special gland in the spider’s abdomen. Using their spinnerets, spiders apply a physical force to rearrange the protein’s molecular structure and turn it into solid silk.

Well? Get right on that!

What the hell, Chad?

After Chad and Yara hit it off and mated, I started shuffling Chad off to meet other spider ladies. First up, I paired him with Melisandre.

This morning, I find one live spider and one dead spider. My immediate thought was that the little witch had murdered the male, but no — Chad was fine, it was Melisandre’s corpse that was dangling from a silken thread. This is not right. Chad, you brute. Now I hesitate to move a known domestic abuser to a new cage, the rotten killer. Mate, don’t murder.

I suppose it’s possible Melisandre lost her magic necklace and just died of old age…

Oh, how I detest textbook publishers

I was not going to go into the university today. It is miserable outside — bitter cold, stiff winds, piles of drifting snow — and I had resolved to stay warm indoors and focus on getting prepped for spring term classes. And I did! I was about to post the first homework assignment for my class, and I was double-checking all the details, when I noticed that the list of textbook problems was from the 10th edition of Concepts of Genetics, while the syllabus specifies the 11th edition. Oh no, crap. If there’s one thing I know, it’s that this publisher loves to fuck around with problem numbers. They may not have changed a thing in the content between editions, but they will still juggle around the order of the problems and call it a new “edition”.

I did not have a copy of the textbook at home. Therefore, I had to put my pants on — and boots and scarf and hat and gloves and heavy coat — and wade out into the wilderness to my office. Yikes, but it was cold. There were knee-high drifts of snow on the sidewalks at the university, which has not been cleared at all since we’re still officially on break. I nearly lost my hat to the wind twice. I stumbled in one drift and twisted my ankle…I think it’s OK, but it was also numbed by the cold, and I’ve been discovering that all I have to do is roll over in bed nowadays and something will ache, so I’ll probably be feeling that tomorrow. But I got my copy of the textbook! I staggered home, sat down, and started to pull out the changes when…sudden terrifying thought, what is the latest publishers edition?

It’s 12. Not 11, not 10, 12. I don’t have a copy of that. Goddammit.

Oh well, I’ll do the extra work I’ve often had to do: I post the problem numbers of the edition I’ve got, with the beginning phrase of the problem, and tell the students to figure it out. You know what we’re doing this first week? A review of basic probability and statistics, and an overview of simple Mendelian genetics, stuff that hasn’t changed in 50 to a hundred years, but we’re going to gouge $174.25 out of the students to get the latest arrangement of textbook problems.

(I do tell the students they should feel free to order older, much cheaper editions because of this absurdity.)


On the bright side of things, I had a chance to duck into the lab and check on Mrs Yara and Mr Chad. No eggs yet, but I’ll put some photos below the fold.

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What good are virgins in a developmental biology lab?

I’m back! I survived my trek to the lab! It wasn’t as bad as I made it sound — the wind is biting, and the snow is coming down sideways, but it’s fairly light so far — so, except for the wolves and the yeti that tried to block my path, it was a reasonably easy trip.

There were reasons I was eager to go in. I’ve been getting anxious, because I’ve got all these new generation spiders, and they’re all virgins because of the shortage of males. I need them to lay eggs! I’ve got new students who want to work with me this semester, and it’s hard to do developmental biology with a bunch of virginal female spiders not producing embryos for us.* That one pair mated yesterday was a promising start, so there were a few things I wanted to do.

  • See if Yara had produced an egg sac. She hadn’t, but there were signs that she was nesting, with some debris pulled up into her favorite corner (which makes me think she might be Parasteatoda tabulata, too.)
  • Make sure her current partner, Chad, hadn’t been eaten. He was fine.
  • Feed her some more, both to make her less likely to eat the male, but also to fuel a little more egg production. Mission accomplished.

Does she look plump to you? She does to me, a little bit. Also her abdomen is paler than it was yesterday, I think. Come on, mama!


*There are some behavioral experiments we could do, but really, development is where my brain is at. We’ll see what interests the students.

Ferda! Also, Yara ♥ Chad

You’ve missed the spiders, haven’t you? I was away for a week, and only today had time to spend a long morning working with them. They’ve been growing; I fed them a lot before I left, and when I came back I found that almost all of them had molted.

I gave them all a lot of flies today, because we’ve got another of those blizzards coming in tomorrow, and I may not be able to make it into the lab for a few days.

One big problem is that I’m down to only two Parasteatoda males, and no males for Steatoda triangulosa. This happened last year, too — the males are so much more fragile and they die off more rapidly. I resolved to invest more effort in raising da boys so this wouldn’t happen, and I didn’t do enough, obviously. Next year! I’ll do better! Or if I get a nice clutch of eggs to hatch soon, I’ll segregate the males and females as early as possible and make sure they’re well fed and protected.

Which may happen…

This is Chad, the biggest male I’ve got. Look at those bulging palps at the front of his head!

Chad got his chance. I put him in the cage with Yara, and they hit it off immediately. Yara scuttled over to him, and there was a bout of touchy-feeling probing, legs everywhere, and then she presented her epigyne to him, and he scurried right in there with those masculine palps. No fighting! No running away! I have high hopes for this encounter.

Aww, isn’t that sweet? I’m leaving them together for the next few days to make sure, then Chad is going to be introduced to some other ladies around the lab.