Now for something totally different. I’m gearing up for a project in which I track the developmental progression of pigmentation in juvenile spiders, and along the way, also map out variation in that pigment. Analyzing all that will require a fair amount of data; I’ll have to do a daily collection of pigmentation images for a single cohort of spiders, and organize those for analysis. I have a poor idea of how much time that will take, so I did a speedrun this morning. I lined up 6 containers of juvenile spiders (all S. triangulosa from the same clutch, plus one S. borealis of roughly the same age), and racked them up for fast photography. I gave myself 30 seconds per spider to get a photo series, which turned out to be easily done, the fastest part of the whole process.

Then I took all the images and made a focus stack, which took a while but since it was all automated was fairly painless. Then I rotated all the images to the same orientation, anterior upwards. First glitch: some of the spiders were annoying and presented a side view to me, rather than the dorsal view I wanted. I went with it anyways; the only way to get them to oblige is to catch them in repose in the appropriate position, so that’s going to take a couple of trials to get right. Next, everything was scaled to the same size.

Data collection: a few minutes. Processing the images: over an hour. I think I’ll be able to automate some of the processing, though, which ought to simplify and speed it up. The end result is a series of standardized images of 6 spiders in which I can see the dorsal pigmentation fairly well, although two of them were not compliant about lying in an optimal position.

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Today was a feeding day, and since I’m trying to include some variety in their diet, I gave the spiders mealworms. Nice plump mealworms, conveniently placed directly in their webs.

They all turned up their noses, or what passes for noses, at them. They didn’t exhibit the slightest interest, which was disappointing after their spectacular voraciousness when fed waxworms last week. I don’t know whether it’s that they’re still full, or they just don’t like mealworms, or they’re just being obstreperous. I told them, “If you don’t eat yer meat, you can’t have any pudding. How can you have any pudding if you don’t eat yer meat?” and even that left them cold and uncaring.

So no pudding today, ladies.

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All right. One spider is nibbling on the delicious meal I prepared. Gilly gets pudding!

The pudding being served today is Jellied Beetle Grub Guts. I hear it’s very popular in England.

Some people mentioned I should try focus stacking on my spiders, so I fumbled around and found some inexpensive software to do it, and gave it a shot. Here are a couple of trial runs (including some spiders I photographed in a single plane yesterday.

I’m just going to say…nice. Also easy. I always take multiple shots anyway, so I just do what I always do, maybe being a little more careful about centering each shot as identically as I can, and then dumping 4-8 photos into the software. I especially like how the juvenile in the third image turned out, letting me see individual hairs on the legs while not compromising the sharpness of the abdominal pigment pattern.

A few words about how I’m doing this: this is my Spider Studio.

It’s nothing fancy, as you can see. I’ve got a Canon body and a speedlite; I’m using my lovely Tokina macro 100mm lens, with a couple of tube extenders for extra magnification, and there’s also a big white diffuser there. I’ve got a bright LED panel to the left and back, and a simple clamp light with a full spectrum light on a jointed arm.

There are some colored papers on the bench top that I can use for backgrounds, but they don’t matter much with the big adults, who are usually hunkered down in a corner of their cardboard frame. The camera is stationary on a tripod, and I’m doing everything manually, focusing by holding the spider’s container in one hand and moving it back and forth, while in the other hand I’m holding a remote trigger and clicking away madly. The juveniles are contained in these clear plastic boxes, about 5cm square — I just pop off the lid, and there’s plenty of light from all around to illuminate the animal.

Hey, if handheld focus stacking is good enough for Thomas Shahan, it’s good enough for me. I was worried that I was going to need a fancy optical bench and something that would allow me to do precisely calibrated advancement of the camera focus, but nah, it turns out to be far easier than I feared.

I was also concerned because I’d seen all these finicky tutorials about using Photoshop or some other software to prep and align each frame, which was going to be tedious. Nope, don’t need that either: I found a program called Focus Stacker that does automatic alignment and assembles all the images into a single sharp result. It’s totally mindless, which I need: shoot a bunch of images with changing focus, drop them into Focus Stacker, and a few minutes later it presents you with the stacked image. I’m going to do this with all my spider photos from now on!

The spider colony wasn’t very lively today. Everyone is still bloated from that waxworm feast last week, and even when I threw flies right into their webs they wouldn’t move — they just sat there, at best they might waddle a bit and desultorily wave a claw at such mundane fare. They now expect more. I promised them mealworms for tomorrow, but no, this is not enough, they have acquired a taste for larger prey.

“Bring us man-flesh,” they whispered.

I countered by telling them that in their current state, they weren’t going to be able to run down a baby, let alone a college freshman. They waddled towards me and hissed, which wasn’t too scary. They look like barrage balloons with a couple of feebly waving legs underneath. Like this:

Look at that! She’s not in a state to scamper at all. She’s huge.

Also pretty. Parasteatoda has these mottled rings of pigment in shades of black and brown, not at all flashy, but subtle and elegant. With abdomens so distended, they’re easy to admire, too. (by the way, the white circle top right is scrap from a hole punch, so you can estimate the size.)

They’re also marvelously variable. Here’s another Parasteatoda with an abdomen that looks like it was made up as an abstract mosaic. If you stare at it long enough you’ll see patterns. I’ve got my eyes open for one with Jesus’s face.

Right now I’ve got a bunch of full-grown adult females that are mostly immobilized by their gluttony, and then a largeish collection of juveniles in the incubator. I’m hoping to upgrade some of them to the larger cages soon — probably over Christmas break — and then I’ve got to introduce males to these young virgins. The Parasteatoda babies really are babies, tiny little spiderlings, that will take a little longer. Meanwhile, the next generation of Steatotoda triangulosa are coming along.

I’ve also got a few S. borealis, but I’m not sure I want to expand their numbers, since the Parasteatoda and S. triangulosa ought to be enough to keep me busy. On the other hand, S. borealis is so goth, with their blackish-purple bodies and gray racing stripes.

They also grow to a larger size. I may have to keep a few around looking badass.

But I don’t think my spiders would be able to move. Look at Texanne here; she’s so bloated she’s not going to step out of that corner, I don’t think.

A few others are purging themselves into egg sac construction.

Anyway, I’ll check on them tomorrow, and as soon as they get active again I’ll throw them some more bugs full of ichor. The menu for Monday is mealworms.

Today was not a good day. My mission was to sort out the prisoners the newly emerged spiders into separate containers, and also to try to document the morphology of 4 day old Steatoda triangulosa. I started out well enough, using a small paintbrush to delicately pluck out the babies and move them, and then to snap their picture.

First problem: somehow, my scope had drifted out of whack, and the eyepieces were no longer parfocal with each other, or with the camera tube. This demanded immediate fixing, especially since the photos were coming out blurry and bad.

These were not acceptable. So I spent an hour fussing over the optics, tweaking the eyepieces, taking a bunch of photos of the tips of watchmaker forceps, etc., etc., etc., until I thought everything was nicely aligned. Then resume shifting spiders.

I was feeling pretty darned competent, deftly plucking up itty-bitty baby spiders, lifting them by their dragline to a new home, and then tossing them a few fruit flies. I got so confident that I deftly knocked over the source container, sending baby spiders flying all over the floor. Oops. Sorry, neighbors. Don’t worry, they won’t go far. I was down on my hands and knees trying to find them, but nope, they are very tiny and I’m pretty sure they made it to the Swiss border. I expect they’ll colonize the space under my benches quite nicely.

Well, that was about ten spiderlings lost in the architecture. So I decided I’d check out this large collection of egg sacs brought back from Texas. At a glance, though, I could tell they’d already all hatched out — after embryogenesis, they molt, and you can see the rumpled white sheet they’ve discarded inside, and then before they emerge, they molt again, leaving their spider-shaped cuticles behind. To be sure, I opened up the sacs and looked carefully, and nope, nothing but shed leg chitin everywhere.

No more spiderlings to deal with today. I do have some egg sacs in the adult cages that will probably hatch out in ten days or so.

Oh well. While I was down on my hands and knees, I did discover a previous escapee near the floor and baseboards. She was looking good!

I don’t know what she’s been living on, but she’s grown. I like to think my lab is a healthy, biologically rich environment, though, so it’s good news. I thought about scooping her up and putting her in the incubator, but instead decided to throw down some fruit flies. She snapped them up fast!

Don’t tell the custodian.

This has been a klutzy day, so I’m out of the lab for a bit, will focus on preparing for class tomorrow instead.