Observations from the Spider Lab

It was a busy morning, good thing I got in early today.

  • I have too many spiders.
  • I fed the growing horde of 2nd generation Steatoda triangulosa. I’m discovering that after their 3rd molt, they are no longer content to wait quietly in their tubes for flies to rain from the sky — they rush for the exits when I pop the tops, which means I have to work fast to feed and re-cork everyone.
  • Two spiders escaped this morning. I let ’em go, I’ve got too many spiders.
  • The first of the 3rd generation hatched out today, after 26 days of incubation. There were 45 of them. These are the progeny of 2g-4 and 2g-7. I put about half of them into individual vials and threw a bunch of flies at the remainder. I have too many spiders.
  • Another 3g egg sac was laid a day after the 4-7 sac. I think that means I’ll have another hatching soon. More spiders!
  • Looking ahead, these 3g spiders should reach maturity sometime in November, I’ll do another round of matings and get some more egg sacs around that time, and then…the 4th generation for Christmas. Even more spiders.

If I keep this up, I do believe I’ll be able to start doing some genetics in the spring, optimistically.

New baby picture at the Patreon.

Everything everywhere all at once, spiderling edition

This week is a mess: I gave an exam, I need to get it all graded. I have two students doing senior seminars, with rehearsals tomorrow and the day after. We have two — count ’em, TWO — faculty meetings this week. And then there’s the usual course load.

So of course this is the day another Steatoda triangulosa egg sac has to start spewing spiderlings. It doesn’t look like much right now, that blurry dark blob is the egg sac itself, and I count a whole six newly emerged spiders, but more will be coming in the next day or two. Just these few are a handful, as soon as I popped the lid they were rushing to balloon off into the sunset. We have an experiment in mind for this batch, so we’ll be setting that up real soon.

Oh, right, this also meant that this morning I was frantically scrubbing the dishes I’ve been neglecting in the sink, because we’ll need a lot more containers.

It doesn’t look like much, but tomorrow that will be a seething box of baby spiders.

Jackie Chan of the spider world

They’re a little guy, capable of absurd acrobatic stunts to take out a bigger opponent. It’s Euryopis umbilicata!

“It has this crazy way of hurtling itself at an ant, doing this fabulous cartwheel then, like Spider-Man, attaching a piece of silk in mid-air to the ant,” said the study’s senior author, Prof Mariella Herberstein of Macquarie University.

“Then it keeps on twirling away from the ant while the ant is being captured. At that stage [the prey’s] fate is sealed.”

I’ll have to see it to believe it.

Yep. That’s Drunken Spider style.

I’ll have to show the video to my spider colony. They have a rather sedate and unspectacular style of just charging forward and stabbing their prey with a venomous fang, no flash or style.

Listen to them. Children of the night. What music they make.

It’s unfortunate they’re so hard to hear, but did you know that spiders can make sounds?

Instead of catching flies in a web, the wolf spider hunts and runs down its prey, including small bugs and even other spiders. They have excellent night vision and because they make a hiss-like sound, they are among the so-called hissing spiders.

“Hissing is kind of a misnomer,” Dill said. “What they do is actually called strigulation, like crickets do when they rub their legs together.”

In the case of a wolf spider, it makes sound by rubbing its front legs together.

“Those front legs have hairs that are best compared with Velcro with little hooks on the end,” Dill said. “Some people say it sounds like a hiss when they hear it.”

The behavior is partly a defense strategy and, for the male spiders, mating behavior. In fact, they will turn up the volume during mating season by rubbing their legs while sitting in a pile of dry leaves, according to Dill.

“The rustling of the leaves helps them make more noise,” Dill said.

I don’t think my quiet little Theridiidae make any noise — they’re homebodies, they’re interested in vibrations but not at any detectable auditory level — but now I’m tempted to get some teeny tiny sensitive microphones to check them out.

Also…here is the required “creature of the night” video.

BEEFCAKE!

Well, today is another overloaded day, with a lab this morning, and then I volunteered to take a group of students on a spider tour of campus (we’ll walk around and do some observations), and then I have a division meeting this evening. But somewhere in there I’ve got to set up some Beefcake Fruit Flies for an experiment I describe on Patreon. Yeah, it turns out you can bulk up flies with dietary supplements. It’s true. I’m going to see if musclebound flies are better for spiders.

If it works, look for my profitable line of Spider Food Supplements on sale online.

I suppose I could ask if beefcake flies make beefcake spiders, and feeding beefcake spiders to birds makes beefcake birds, which could in turn be consumed by people…but that’s getting too renfield. It’s always a danger that one can be tempted to go down the renfield path.

Spider journalism isn’t great

I knew it all along. What I read in the popular press about spiders seems to be a lot of spook stories — it isn’t news unless it reaffirms peoples’ fears. I’ve wondered how bad the reporting is, and now it’s been quantified: a bit less than half are sensationalist. That’s slightly better than my impression, but still awful.

Overall, the quality of the reporting was poor: 47% of all articles contained one or more errors and 43% were sensationalist. Stories with photos of spiders or alleged bites were more likely to be sensationalized, as were stories that contained errors. Whereas quotes from medical or other experts were unrelated to sensationalism, stories that contained quotes from spider experts were much LESS likely to be sensationalized.

If it bleeds, it leads — or if it has fangs, too many legs and eyes, and is venomous, it justifies a freak-out on page 3. What to do about that?

We next conducted an analysis to describe the flow of spider news stories around the world and to get at what may be driving the spread of (mis)information about spiders online. Unsurprisingly, countries with shared languages and with higher proportions of internet users were more likely to be connected in the global network. The number of medically important spider species present (i.e., those capable of harming and potentially killing humans) also increased the connectedness of individual countries within the network. Most notably, we identified sensationalism as a key factor underlying the spread of (mis)information.

This study provides insight into what drives the global flow of information about spiders in particular, but can also teach us some more general lessons. Our results make us optimistic because they suggest a way to improve reporting on spiders, and in turn, to shift the quality and spread of online information more broadly. News stories are less sensationalized when they consult appropriate experts, and reducing sensationalism can help decrease spread of misinformation. We found that even local-scale events published by regional news outlets can quickly become broadcast internationally, which means improving news quality at the local scale can have positive effects that travel through the global network.

Journalists, you know you can pick up your phone and call your local university or extension service and contact someone knowledgeable about the species you’re planning to libel, right? It’s not hard, it makes your story better, and it doesn’t compromise your integrity. It would be less lurid and melodramatic, though.

Besides, everyone knows that spiders are really cute and playful.

The orgy had a happy ending

First thing I had to check in the lab this morning was the status of the spider couples I’d paired off yesterday, one pair seen in this video. I half expected carnage, with the grooms all bled dry and the brides bloated with spider juice.

But no! No deaths at all! All of them were resting quietly, a couple of them were even snuggled up together. It was very sweet. I still separated them all this morning, you know, just in case. After class today I’ll be moving the females into extra-large, roomy, deluxe cages, where they can produce all the egg sacs I could dream of. Don’t tell them, but I’ll need a fresh egg sac soon — I’m going to be popping out eggs and embryos, fixing them, and staining them a few at a time over the next few weeks with DAPI. Anyone got a good DAPI protocol for spiders? Or fruit flies? (This one will probably do. I also see that the embryos at the mid-blastula transition look, in some ways, like good ol’ zebrafish.)

Germ-disc formation in Parasteatoda tepidariorum. A contiguous blastoderm is present at stage 2 of embryonic development. The mid-blastula transition (MBT) is at the end of stage 2 and germ-disc formation needs the onset of zygotic gene expression. The germ-disc is formed by a condensation like mechanism. Cell membranes (red); nuclei (grey circles); perinuclear cytoplasm (black); yolk (yellow). Upper left corner: schematic representation of the cross-section of blastodermal cells (st. 2). Upper right corner: schematic representation of the cross-section of germ-disc cells (st. 4). Lower right corner: schematic representation of the cross-section of an extra-embryonic cell (st. 4). Not to scale

Meanwhile, that other egg sac I’ve had my eye on as being close to emergence is still doing nothing. The biggest difference between Parasteatoda tepidariorum and Steatoda triangulosa that I’m seeing is that P tep develops like lightning while S stri dawdles along. That may be an advantage for me since I have to interleave everything with a fairly robust teaching load.

Girls get growth spurts

This is a fairly trivial change, but I color coded the growth rate data for Steatoda triangulosa (yellow for females, blue for males), and what jumps out at me is how the females so distinctly surged in size above the males. It’s also obvious differences in morphology, with the females developing enormous abdomens and the males looking lean and rangy.

Also, some of the females started out as the smallest of the cohort, but even they started surpassing the males in the last two weeks.
Now, unfortunately, I am summoned to the doctor’s office for more tests (no worries, all routine), which means I have to wait another hour for the answer to the question: did any of those little males survive spending the night with the majestic massive females?