Spider Math

I have spent many hours today, counting spiders. I’m trying to keep track meticulously to figure out where the danger zone in spider raising is, and I don’t think I’ve reached it yet. I’m dealing with 3 clutches of spiders from 3 different mothers and 3 different fathers (they were caught in relatively different locations), and I’m simply tracking numbers right now.

Runestone line, 16 days old: 22 spiders, 96% survival, density of 1.1/vial.

Horticulture line, 15 days old: 94 spiders, 90% survival, density of 2.2/vial.

Myers line, 14 days old: 71 spiders, 93% survival, density of 3.0/vial.

There’s an accidental experiment in there. The first hatching from the R line was small and manageable, we were able to quickly and efficiently move them into vials, no sweat. They’re mostly living as single spiders in each vial.

The H line, on the other hand, just erupted with lots of spiderlings and we were a little overwhelmed and rushed. A fair number simply escaped, some we just gave up on and left in the cage with their mothers, and we were straining to get them all contained…so we had on average 2 per vial, and the max was 5 in a single vial.

The M line also taxed us, because I ran out of racks to store all these tubes. We tried to get as many as we could into the available slots, so there you go, on average 3 spiders per vial. I could at least look and see if the density in the first few weeks of mobility made a difference in survival.

And no, it doesn’t seem to. In fact, most of the deaths were in vials with single spiders, which makes me wonder if there might be some cooperative work in bringing down fruit flies, which are much bigger than the spiderlings. I did see, though, that big size disparities are emerging — some individuals were twice the size of their siblings in the same vial. I haven’t seen any sign of cannibalism yet, but that may arise if I don’t keep everyone well fed. Which reminds me, I’ve got 187 spiders down in the lab waiting for dinner.

The spider struggle continues

13 days until classes begin, and this last batch of spiders are now about 13 days old. I took a few pictures (I stashed one on Patreon and Instagram) and had to struggle a bit with the photomicrography system, which I’ve mostly neglected this summer, on top of struggling with putting a lab demo together on video. Tomorrow is going to be busy feeding a few hundred spiders…well, maybe. Another thing I’ve noticed is that some of the babies have died, just out of natural mortality, I think, and tomorrow will involve counting the living and the dead, hoping the former outnumbers the latter.

Somewhere in here I’ve got to get my syllabi order, too.

Mighty Huntress

I learned something today! There is this spider I keep on my office desk. I’ve always wondered, since these spiders are so passive and patient, and I’m feeding them wingless Drosophila, do they just wait until one stumbles into their web, or do they ever actively hunt? The answer is…they’ll hunt when opportunity arises.

So this spider has webs strung across this wooden frame, and she tends to hang out near the top of one of the sticks.

This afternoon I watched her abruptly descend on a drag line from her perch to the gravelly scree directly below to drop on a fruit fly walking by, bite to kill, and wrap it in silk before hauling it right back to her starting point. It was spectacular!

In case you’re squeamish about this sort of thing, I’ve put a closeup of the proud hunter below the fold.

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ENCODE is back, and Larry Moran is on it

The ENCODE project is a massive international program to get papers in Nature, and as Larry notes is better described as a publicity campaign than a research project. Every couple of years they pop up with another paper with sensational, but unfounded, claims — in 2012, for instance, they claimed that 80% of the genome was functional, using a wobbly and useless definition of “functional”, and the creationists loved it. They still fling that claim in my eye every time I engage them.

But this time around they’ve dialed the hype-meter down, which is good, I guess. It does mean the paper is dry as dust and not particularly interesting, with nothing but description.

Both of these publicity campaigns, and the published conclusions, were heavily criticized for not understanding the distinction between fortuitous transcription and real genes and for not understanding the difference between fortuitous binding sites and functional binding sites. Hundreds of knowledgeable scientists pointed out that it was ridiculous for ENCODE researchers to claim that most of the human genome is functional based on their data. They also pointed out that ENCODE researchers ignored most of the evidence supporting junk DNA.

ENCODE 3 has just been published and the hype has been toned down considerably. Take a look at the main publicity article just published by Nature (ENCODE 3). The Nature article mentions ENCODE 1 and ENCODE 2 but it conveniently ignores the fact that Nature heavily promoted the demise of junk DNA back in 2007 and 2012. The emphasis now is not on how much of the genome is functional—the main goal of ENCODE—but on how much data has been generated and how many papers have been published. You can read the entire article and not see any mention of previous ENCODE/Nature claims. In fact, they don’t even tell you how many genes ENCODE found or how many functional regulatory sites were detected.

In summary,

The ENCODE Consortium seems to have learned only two things in 2012. They learned that it’s better to avoid mentioning how much of the genome is functional in order to avoid controversy and criticism and they learned that it’s best to ignore any of their previous claims for the same reason. This is not how science is supposed to work but the ENCODE Consortium has never been good at showing us how science is supposed to work.

What it is is good public relations. Gotta keep the money flowing in and papers flowing out, you know.

Everyone needs a pet spider!

If there’s just one thing I miss from my zebrafish days, it’s being surrounded by fish tanks. Lovely burbling fish tanks, filled with little dancing fish, so soothing. So nice. So restful.

Well, they’re gone now, so I wanted something to replace them, so I threw together a couple of terraria with spiders. It was easy. First I thought of repurposing all these fish tanks I’ve got, but they’re too large — my spiders are small, these aren’t tarantulas — and the lids were perforated and wouldn’t be any kind of obstacle. Then I found these acrylic display boxes, which are intended for 1/32 scale model cars, or dolls, or action figures. I can do better than that — spiders! So I made a few.

The one on the left holds a bronze jumping spider and a chunk of stick, while the one on the right is Parasteatoda with a simple frame I slapped together with coffee stirring sticks and hot glue. The jumper has its own charm, but is a little on the small side right now (I’ll fatten him up). The house spider is fascinating and is a real distraction in my office. She immediately started assembling a web on the frame, scurrying about, jumping from stick to stick. I really recommend them for everyone’s office. You should get one or two or four.

I also needed some distraction. Oh no! Another egg sac erupted with babies!

I’m not sure what I’m going to do. My incubators are full to capacity. I might have to try feeding them en masse, until they’re big enough to thrive, and then turn them all loose somewhere. Like my house. Mary won’t mind.

Alternatively, you could all buy some of those acrylic display boxes, stop by the university, and I could stock them up for you. Seriously! They’re fascinating! Like aquarium fish, only dryer!

In case you have no idea what you’re looking at in that last picture, here’s a key.

Hope that helps!

Spider feeding day!

It’s been a long day of preparing my mighty army of baby spiders. All have now had flies sacrificed to them, so while I was flicking flies into vials, I recorded and uploaded this short clip of one Parasteatoda happily finishing off her prey.

They are so young, and yet they’re already murderous hellbeasts. At least from the perspective of Drosophila.

Spiders of the Industrial Wasteland

Today I had to take the car in to get new tires. We’re a rural bit of the country, but that doesn’t mean we’re all green and soil and fresh sprouts — this was a tire store next to the railroad tracks with a line of grain elevators across the street. I wasn’t about to hang around in the waiting room, so I went prowling about the industrial wasteland next door.
What did I find? Cryptic machinery, corrugated sheet metal buildings, and iron rails, of course. With spiders!

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Dispelling the aura of danger around spiders

I keep telling everybody — spiders aren’t as scary/dangerous as you think. Now I have a paper that quantifies the risk of deadly spider venom. It’s low.

• The increasing popularity of pet arachnids urges some governments to take protective steps to prevent serious envenomations.

• A literature review was carried out to assess which arachnids can be classified as potentially dangerous.

• About 0.5% of all spider and 23% of all scorpion species were classified as potentially dangerous.

• Even envenomations from the most dangerous arachnids have a low percentage of serious or even fatal consequences.

• We conclude that the public threat from pet arachnid envenomations has been overrated.

Here’s the list of potentially dangerous genera.

Note that the list errs strongly on the side of caution. It lists Eratigena, the hobo spider, but says in the text that “there is not a single verified bite that confirms E.agrestis or other members of this genus as dangerous to humans”. Latrodectus, black widow spiders, do have a real record — 23,000 incidents reported over 8 years — but less than half of those cases involved envenomation, and only about 1% exhibited severe effects, and there were 0 deaths. The Parasteatoda and Steatoda species I work on are only briefly mentioned and dismissed because their effects are much weaker than those of Latrodectus.

I’ve also never encountered any of the spiders they list, and I’ve been looking. I guess if I lived in Malaysia or Brazil I’d experience more of the thrill of danger, but here in Minnesota we’ve got a non-existent concern, and even in those tropical countries it’s a relatively minor worry.

(Of course I learned about this paper from Gwen Pearson. It’ll be useful if anyone at the university expresses concern about the hundreds of spiders currently in my lab.)