You won’t believe the size of this spider!

Yes, I employed clickbait; my bad!

I am not afraid of spiders; in fact, I used to have a collection of about half a dozen tarantulas when I was a graduate student, and would let them walk all over me. (I was never bitten.) They are fascinating creatures and mesmerizing to watch, especially when you see them molt.

The short YouTube video below shows two tarantulas: the Pumpkin Patch (Hapalopus sp.), a small one, and what appears to be a gynormous Goliath birdeater (Theraphosa blondi; it doesn’t really eat birds). Both are from South America. The Goliath is the world’s largest spider by mass; it can weigh up to 175 grams (over six ounces). And the females of both are remarkably long lived: the Goliath can live up to 25 years but, as in nearly all tarantulas, males live only a few years. That’s typical, but if you get a female, and take good care of her, she can live longer than your cat.

Here are the notes on this very short video:

The video goliath vs pumpkin patch shows the size difference between some of South Americas Tarantulas. Both are fully grown adult females. The Goliath in this was recently deceased, and 16 years old when she died. One of the few chances you get to actually stretch these spiders out and get a true idea of their size, just under 11 inches. The Pumpkin Patch tarantula is around an inch and a half across.

I saw tarantulas molt many times, as I kept mine well fed (with crickets and clean cockroaches), and I never got over the sight. It’s amazing to see a spider extricate itself from its body, with the cephalothorax popping open like a tank turret to allow the new spider to emerge, which finally draws each leg out of its old shell like someone taking off pajamas. And the “new” spider was always fresh and beautiful looking. I know nothing about the biochemical and physiological processes behind what see you below (not a Goliath), but whatever happens, it’s a marvel of evolution:


  1. Posted June 22, 2017 at 2:39 pm | Permalink


  2. merilee
    Posted June 22, 2017 at 2:42 pm | Permalink

    eeeeeek! Can’t help myself!

    • somer
      Posted June 23, 2017 at 8:24 am | Permalink

      I know people who’d never speak to me again if I sent this article to them, though have to say Im not overly fond of spiders. Touching them is not as bad as eating them though
      Deep Fried Tarantula anyone?

      • Merilee
        Posted June 23, 2017 at 9:22 am | Permalink


        • Merilee
          Posted June 23, 2017 at 9:26 am | Permalink

          Somer, I did teasingly tell a good friend that I was NOT going to share my tarantula videos with her and she thanked me for looking out for her best interests🐸 There is a (very small) part of me which would like to challenge myself and actually touch one, as long as it wasn’t in my house, and I could get the hell away from it afterwards…

  3. Heather Hastie
    Posted June 22, 2017 at 2:57 pm | Permalink

    Very cool indeed.

    However, I do wish they hadn’t used my favourite piece of classical music to accompany that amazing video of the tarantula moulting. For me, the feeling the music evokes is not what I feel watching a spider moult!

  4. GBJames
    Posted June 22, 2017 at 2:59 pm | Permalink

    I will not share this post with my wife.

    • rickflick
      Posted June 22, 2017 at 5:31 pm | Permalink

      So, your wife isn’t an arachnologists?

      • GBJames
        Posted June 22, 2017 at 6:28 pm | Permalink


  5. ploubere
    Posted June 22, 2017 at 3:29 pm | Permalink

    Sorry, but they creep me out. Can’t help it.

  6. Paul S
    Posted June 22, 2017 at 3:35 pm | Permalink

    Thanks for the heads up. I love to read the sciency bits, I can’t look at them. I can do small spiders in person, large or magnified spiders are off the list.

  7. Posted June 22, 2017 at 3:43 pm | Permalink

    You got me beat there, Professor C., as I never had more than two tarantulas at a time. My tarantulas were not pale like this one upon molting, but I do remember their enormous fangs were ivory white. The one that would most definitely bite had escaped from her pen, and I never did find her…

  8. darrelle
    Posted June 22, 2017 at 3:44 pm | Permalink

    Spiders creep me out. I can deal with them, but . . .

    So, raising our kids I tried hard to not bias them too much. For example by freaking out over spiders and thus instilling in them an irrational fear of spiders. This led to situations where one of the kids would find a cool spider, pick it up, have it crawling all over them while proudly showing it to me while I try to not let slip any hint that I am actually on the verge of a fight or flight reaction.

    Now my kids are better than I am in most ways and I try to live up to their example.

    • BJ
      Posted June 22, 2017 at 4:37 pm | Permalink

      The weird thing about my phobia is that my parents have never been afraid of spiders or bugs and never taught me to be either, but I’ve always had the phobia anyway. I don’t know where it comes from; all I know is that *I cannot deal with them*. No way, no how. Not happening.

      • rickflick
        Posted June 22, 2017 at 5:35 pm | Permalink

        An evolutionary biological explanation might be that you evolved from a species who’s environment contained a certain number of poisonous/deadly insects and other scurrying critters. Your line of decent comprises those who had a genetically based healthy fear of bugs.

        • BJ
          Posted June 22, 2017 at 5:59 pm | Permalink

          Would such genes be recessive? Neither of my parents have any problems with bugs or spiders.

          But let’s go with that explanation, since it’s either that or I’m just weird/crazy.

          • rickflick
            Posted June 22, 2017 at 7:01 pm | Permalink

            You could always blame it on your amygdala. The amygdala is the reason we are afraid of things outside our control. Spiders may seem outside our control because they often move quickly and catch us by surprise. That’s better than just weird/crazy.

            • BJ
              Posted June 22, 2017 at 8:37 pm | Permalink

              That’s why one of my biggest fears is crickets! Those things are so damn fast and you never know when they’re just going to start jumping, nor which direction they’re going to go. Are they going to jump at me? And then bite my face off? I don’t know!

      • Posted June 22, 2017 at 9:47 pm | Permalink

        I was just today talking about a lady we knew who was phobic over turtles. Even a stone pendant of a turtle would send her into the next room.
        So maybe there is a greater propensity to have phobias about spiders and snakes, but it goes to show that it can more rarely develop over just about anything.

      • darrelle
        Posted June 23, 2017 at 7:26 am | Permalink

        It sounds like I’m not quite as phobic as you, but enough so to understand exactly what you mean. I got stories!

  9. Posted June 22, 2017 at 4:14 pm | Permalink


    nope nope nope nope

    • BJ
      Posted June 22, 2017 at 4:36 pm | Permalink

      Seriously, spiders and bugs scare the hell out of me. I often let out a little yelp when I’m just flipping through a magazine and unexpectedly end up seeing a picture of one.

      I demand trigger warnings for all posts on spiders!

  10. David Coxill
    Posted June 22, 2017 at 4:46 pm | Permalink

    Really doc ,can’t you stick to Cats and Squirrels ?.
    Years ago i tried to get over my fear of spiders ,i bought a book full of photos ,one day book in hands ,number one niece(aged 6) on lap i began to leaf through it .
    I swear the photo of a giant spider moved ,book and niece parted company from me as i stood up .
    No lasting damage ,the book was ok.

  11. Posted June 22, 2017 at 11:00 pm | Permalink

    Biology is wondrous and wonderful – but spiders the size of my dog? Nay-nay no-no.

  12. Jonathan Dore
    Posted June 23, 2017 at 4:44 am | Permalink

    The moulting video is really remarkable. I was trying to imagine what it must be like to do that, and the best analogy I could come up with was trying to remove a disposable glove from an eight-fingered hand but without the help of an opposable thumb on another hand. The spider must be utterly exhausted at the end of it.

  13. Posted June 23, 2017 at 12:45 pm | Permalink

    Yes, pretty big but it doesn’t beat the spider I saw in 1990 at La Selva lodge on the Rio Napo in Ecuador. We had gotten back after a day trip and most of our group went to the common dining area to discuss the trip and wait for dinner. But I wanted a quick shower before it got dark so I went to our cottage, grabbed a towel and went to our shower. Holy moses! High up on the wall was a spider that looked a cross between a B1 bomber and a Japanese heavy metal insect from a manga comic book. Not fuzzy. Thorax and abdomen light grey, smooth, with a black mark in the middle and huge legs out to the side. For some reason I didnt have a camera so I started yelling to people to come with one quickly but no one heard me.So I just looked at it for a while but it was getting dark and I wanted my shower so I turned on the water faucet and of course it disappeared quickly up into the thatched roof.How large it was? I really dont know but it must have been at least ten inches wide including legs, and body at least four inches across.
    If anyone has been to La Selva or Ecuador and seen something like it, let me know!

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