Thursday, 7 April 2011

Gold Silk Orb-Weaver Spider

The female Golden Silk Orb-Weaver (genus Nephila) can be up to 18cm (7.2inch) toe to toe while the males are 2/3 that size. The females are so big that they are known to catch small birds and small lizards in their huge webs and eat them. If any spider will induce arachnophobia, this would be the one - they're huge! If you put that aside, they are quite a beautiful creature, sporting colours like yellow, white, orange, black and red in a variety of patterns unique to each spider. Most of the time they have black, orange and red striped legs, a white thorax and orange/red abdomen with white spots. They are solitary spiders only meeting to court, they are not very aggressive but the female will eat the male after courting if the male does not get away fast enough. Talk about a one-night stand.

The female will wrap her eggs in a silk pouch, then cover that in a brownish silk and most of the time hang it from her web so she can keep an eye on it. An egg sack can contain 300 to 1000 eggs. Spiderlings (babies) do not have fully developed venom glands, mouths, digestive tracts or the ability to spin their own silk. They will live with their mom for while until they cannot tolerate each other (other Spiderlings), at which point they will cannibalize each other. They usually leave not long before that point and start making their own lives.

They are not aggressive toward humans but they will bite if they feel threatened and cannot escape. If they feel threatened they will vibrate their web at a 40MHz frequency to try and warn the possible threat to back off. If that does not work then they will run, drop or jump away in the bush or foliage. If they do decide to defend themselves they have large fangs that can scar even hard tissues like the tissue on your fingers. Their venom* is potent but not lethal to humans, their venom is a neurotoxin like the Black Widow's but not nearly as strong. It will cause some swelling and blistering in the bite area that will only last for a few days unless you have an allergic reaction.

The most EPIC feature of this spider is the web they weave, they spin a huge orb shaped web that is yellowish-gold in colour when the sun is shining on it. Experimental evidence suggests it serves two purposes: the sunlit areas of the web attract bees that are attracted to bright yellow strands whereas the shady spots blend into the background foliage. The spider can control the intensity of the colour of the web so as to blend in or show more, they will produce more intensely coloured web if there is more sunlight in the area. When this spider weaves its web it makes a huge web one meter or so across. It first weaves a non-sticky spiral, then 2 to 20 more sticky spirals in between and when she is finished she will go in and fill in all the gaps. There are usually many support strands reaching many feet away. An adult spider may weave a web anywhere from eye level to high up in the tree canopy. A top horizontal support strand causing it to look incomplete and messy usually truncates the web. The spider has also been known to dismantle the bottom of the web on rainy and windy day to help prevent damage, that is very smart if I don’t say so myself. I do not know if I would think of that.

Some spiders have been known to abandon their web (although it is rare) and another spider may take over the web. When this is done the spider will change and make additions with her own unique style as each spider weaves their web differently. We may not be able to tell the difference at a glance but they are all as unique as every person’s handwriting. These spiders have been given the nickname "Writing Spider" because of the zigzag style the web appears in.

If an army of these spiders where to get together and built a web together they could easily entrap a human - thank god they do not eat us, they eat small birds, small lizards and other insects. Some people have thought that they eat some fruit because they often make webs around fruit but that is actually because it’s a prime location for catching fruit flies which are one of the insects they are most effective at catching. They make a good garden pet as they are effective pest controls and they will work for food, just don't piss it off.

Scientists tried to make their web synthetically and failed, they also tried coiling the thread from a spider (held down while pulling the silk out. Uck.) until it ran out to make clothes from them, thankfully that did not work out either. Some people do make clothes from their silk and there is one on display in the American Museum of Natural History, it took over one million females orb spiders to make it, does not sound like a good idea to me. From trying to do that they discovered a possible use in tissue engineering. A study from Medizinishe Hochschhule Hannover reports that processed Nephila silk is an excellent scaffold material thanks to its biocompatibility, mechanical strengths and it's property to promote cell adhesion and proliferation. Basically it acts as a guiding material for peripheral nerve regrowth. It may help people with nerve damage in the arms or leg, feet or hands and fingers or toes. That seems EPIC to me...

With its size, what it can eat, the amazing properties of its web and web weaving and possible uses of it's silk I deem this spider EPIC.

*Writing this blog I am going to end up talking about creatures with venom and poison so I would like to explain the difference as it is a common misunderstanding that they are the same when they are not. Venom is mostly used for hunting and self-defense, venom needs to be injected and if ingested then it will just make you sick but most likely not kill you. Poisons are substances that can cause damage, illness or death to organisms. Poisons cause a chemical reaction or other activity at the molecular level, this can be done by inhaling, injecting, contact or injecting, every poison is different. Both poison and venom are used for hunting or self-defense and never used in the animal kingdom just to kill. Killing for pleasure is only a human trait.


  1. 7.2 Inches is 18 centimeters, not 120 :)

    1. Yes, thank you! I was going to mention that, myself.

    2. Just what i needed to know. I have several around the house

  2. cats kill for pleasure :/
    recent studies showed that they only eat a small fraction of what they kill, and most domestic cats kill even when well fed, just for fun

  3. Killing for pleasure is not just a human trait. Cats do it too. For example cats like to hunt shrews, which are unedible rodents. They just leave the bodies laying around on the yard. Or hide them in your shoes...

  4. Can anyone tell me why the golden orb weaver in my yard has a clump of old web and old meals slightly above the center of the web? She keeps it there. Unsure what an egg sack looks like.

  5. Cats are simply the most notorious non-simian animals that kill for fun (after all, murder is well documented in chimps and gorillas). Coyotes and other wild dogs will kill for fun, weasels have been documented killing hundreds of chickens in a single attack.