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.


  1. nevillepark says

    Could she be in pre-molt? Sometimes a darker colour (especially on the legs) comes from the new exoskeleton thickening underneath the old one.

  2. says

    I remember a study from decades ago where they gave spiders various kinds of drugs and looked at the webs that ensued. LSD produced a web that was an absolute miracle of order and beauty. Amphetamines produced a web that was a hot mess, a disorganized disaster. So did caffeine IIRC.

  3. brucegee1962 says

    PZ, I’ve been reading the SF novel “Children of Time” by Adrian Tchaikovsky, and I would highly recommend it to you. It’s about a human attempt to terraform a world and then uplift a bunch of apes (in the aptly-named ship Brin when something goes wrong, as it usually does. The net result is that the monkeys never make it and the uplift virus that was supposed to infect them ends up working on spiders instead. So much of the novel is from the POV of intelligent, meter-long spiders, imagining the society they would build. What more could you ask for in a planet?
    I checked and couldn’t find any other mention of the novel on FtB, so sorry if I’m not the first to recommend it. It really is enjoyable for spider-lovers, though. It’s also available on audio.

  4. Sengkelat says

    As I recall, black widow spiders start out fairly pale, and they darken with each molt. Could something similar be going on here?