Scientific Name: Heteropoda venatoria
My Invertebrate: The Huntsman Spider
Life Sciences/Biology 11 – Mrs Mireau – Block A
- I started with looking at types of bees because I have always been interested in their nature and I know that they are at risk of extinction.
- While searching the word wasp I found the wasp spider, and after hearing Mrs. Mireau talking about students commonly picking animals they are afraid of, I decided that I wanted to do a spider instead.
- I wanted to do something that I was really afraid of, and I have always said that I will never go to Australia because of how large their spiders are.
- I thought about the wolf spiders that we have here, and made the correlation between wolf spiders and the Huntsman spiders in Australia. I decided on the Huntsman.
My Invertebrate: The Huntsman Spider
Scientific Name: Heteropoda venatoria
All spiders are thought to have evolved from crab-like chelicerate ancestors. Chelicerata is a subphylum of the phylum arthropods, and several of the animals under this category are now extinct. However, a key characteristic for the organisms in this subphylum is 6 appendages, crab-like, spider-like features. Most chelicerates fall under the Arachnida class, and they consist of both marine and land animals. This means that spiders evolved from originally marine animals to land animals.
Huntsman spiders are land animals, and the oldest known land arthropods are the Trigonotarbids. Trigonotarbids share many characteristics with the modern spiders that we see today, however they are not credited to being direct ancestors. A very small portion of Trigonotarbids did give way to the tetrapulmonates, which portions of evolved into the modern-day spider, including the Huntsman spider. Other tetrapulmonates consist of multiple different types of scorpions, so spiders and scorpions are actually quite closely related. They are also under the class Arachnida.
The oldest true-spiders to date are documented to be about 300 million years old, belonging to the Mesothelae, and the major difference between them and our modern day spiders are the location of the spinnerets. This means that spiders are older than the dinosaurs! The Mesothelae are a suborder of spiders and only have one living family today, the Liphistiidae, the rest being extinct. In the ancient spider, the spinnerets are located underneath the abdomen, and in modern spiders they are located at the end of their body. Spiders with spinnerets located at the end of their bodies were first documented at about 250 million years ago. The principle reason for the change of location of spinnerets appears to be related to the use of their silks. It is thought that with their spinnerets located at the end of their bodies, it is more useful to create more diverse and complex web patterns. Their silks are used to capture prey, both on the ground and on vegetation, climbing, creating webs, creating egg sacs, as well as safety lines. Safety lines are used as parachutes, especially in newly hatched spiderlings. In the ancient spiders, their silks were thought to be used for fewer functions, such as the egg sacs and simple ground sheet webs. The Huntsman spiders spinnerets are located at the end of their bodies.
Huntsman spiders are carnivores and therefore heterotrophic. They are a very active spider compared to others and expel a lot of energy. Usually spiders build webs to conserve energy that would be used hunting for prey, the webs catching their prey for them. However Huntsman spiders do the hunting themselves and actually don’t typically use webs at all in adult hood. Instead, they are extremely agile and move incredibly fast to catch their prey; they can move up to 3 feet per second! They also jump using a spring board motion while running, and some types of Huntsman spiders can even do cartwheels during their runs.
The typical Huntsman spider habitat is rock crevices and underneath tree bark and are most active during the night. They have been nicknamed as Wood Spiders because of their choice of habitat, and they are commonly found in Australia and South Asia. They also have the tendency to find their way into sheds, basements, houses, and surprisingly enough cars; they like to hide behind the sun visors. They are adapted to their small crevices and habitats of choice through their legs. Their legs are unique compared to other spiders, and have twisted joints. This allows them to move in crab-like fashions, anyway they choose, hence the crab movement comparisons. This, along with their long and flat bodies, allows them to fit into these small crevices.
Huntsman spiders are very social creatures and are often found in large groups, up to 300 per colony! They are typically not aggressive, and would rather run away from a human than attack and show aggression, however they can be aggressive and even cannibalistic with other spiders that are not from their colony. Because they are so social, people have gone so far as to describe their mating as romantic. Their rituals can last for several hours, with the male Huntsman caressing his female mate and drumming his palps, shorter appendages located on the head surrounding the mouth (often compared to antenna), along a tree. A certain type of male Huntsman, the Heteropoda venatoria, have recently been discovered to anchor themselves onto a surface, and then release vibrations which creates a sound to attract females that are interested in mating. Once the male and female have mated, through the male inserting his palps into the female, the female lays a sac of eggs created by her silks. The females commonly place the sacs once again underneath a rock or tree bark, however some attach the sacs to the undersides of their abdomens, but this significantly restricts their movement. Females can lay up to 200 eggs at a time, and once the eggs are laid they guard them fiercely. They will stand over their rock or piece of bark for up to three weeks, without eating. Whether they have decided to plant their eggs somewhere or carry them, they become quite aggressive when guarding them. The new spiderlings will crawl out of their sac, however some females have been known to tear open their sacs to help their babies crawl out. The spiderlings stay with their mother for a considerable amount of time, and stay with her through several molts of their skin. After that, they move on by themselves. Surprisingly, the life span of a Huntsman spider is only about 2 years.
Huntsman spiders significantly vary in size depending on their type, however their common feature is their long legs and flat bodies.
The Heteropoda maxima, found in Laos, are the largest Huntsman.
This is a Heteropoda maxima, found in 2001 in Laos, and is the largest spider ever recorded simply because of it’s leg span.
These diagrams are not specific to the Huntsman spiders but a general look at the anatomy of the average spider. It still gives a good look into it’s anatomy as the only main specific trait that Huntsman spiders have are their differently jointed legs.
Huntsman spiders have an average body span of about an inch, with the average leg span being about 5 inches. Some can stretch to almost a foot with their legs outstretched. Most Huntsman spiders are a brown or grey colour, with a few exceptional patterns. They have been compared to have crab like movements which is due to the anatomy of their legs which allows them to splay to the side versus have them curled underneath their flat and commonly hairy bodies.
First Peoples Knowledge:
The legend of Wururi is associated with the Huntsman spiders. It is related to the Native People of Australia, the Ngarrindjeri. Ngarrindjeri means tribal constellation and belonging to men. They are known as a nation of 18 language dialects, the legend telling the story of the dialects originating from the body of the old women, Wururi. Wururi, much like a Huntsman spider, would become active during the night time and would roam, spreading fires as she went. Her aggressive and dangerous behaviours were also characterised by growling. When she died people gathered and rejoiced in happiness, feasting from her body. People from many corners came, and its said that after eating they all began speaking a related language, but with distinctly different dialects. It was speculated that she may have been a tarantula, but once looking at how the female reproduces, it was connected to the Huntsman spider. The females spin a sac for their young and stay with them as they grow, being their source of food, the spiderlings eating from her. Once they are grown, they part, much like how people fed off of Wururi’s body and left full with new languages.
Spiders, specifically females, in general are an important part of Native People’s history. They are seen as life givers and creators. In another legend and a poem called “Grandmother,” a spider is depicted as weaving the world together herself, bringing about new creation from her own body, from pure thought. It is considered a sacred moment of creation. Like in the Huntsman spiders nature of dispersing from their mother once grown, after her creation of the world is finished, she too perishes.
From a personal point of view, I find this connection both beautiful and confusing. Spiders weaving a beautiful creation into existence from their own bodies and giving birth to new things. But in contrast, in Wururi’s legend she is shown as something bad and trouble-causing, and it is only after her death that she creates something beautiful. In both however it shows sacrifice of ones own body to bring about new existence. I wonder why there is negative correlation in one and not in the other. I also wonder if there is a connection to be made between the definition of Ngarrindjeri, meaning tribal constellation, and the gift of the 18 new dialects. It could possibly symbolise the difference and separation between them as well as the connection between them, originating from the same place.
Environmentally, Huntsman spiders are helpful with insect and pest control as they are their meal of choice, specifically cockroaches. Even though they are fast, they also make meals for lots of other animals such as the obvious bird, but surprisingly the much smaller geckoes, spider wasps, and even nematode worms and egg parasites. If the Huntsman spiders were to go extinct, there would obviously be ramifications in the species of their prey and their predators. However, there is not a lot of information out there about what would happen if they were to disappear, or the role they play in our ecosystem. In a broader category, if all spiders were to go extinct, even though that would be a dream come true to most people, the effects would be absolutely devastating and the our ecosystems would fall into absolute chaos. The world would become overrun by insects, as spiders largely contribute to their population control (one spider is estimated to eat around 2 000 insects a year), which would obviously cause a major imbalance environmentally. Obviously farming would be affected, and it’s reasonable to say that almost all of our crops would be consumed by insects, as well as everyone being eaten alive by mosquitoes. Spiders may seem like creatures with no purpose other than to instill fear, but they actually play a major part in keeping the ecological pyramid in check.
Arachnophobia is one of the most common phobias in the world. And while most people consider that fear of the common spider, maybe the size of a toonie that you sometimes find lurking in the corner of a room, Huntsman spiders are the stuff of nightmares. There is a lot of stigma surrounding these animals simply because of their size. Lots of people would assume that they are aggressive and/or dangerous to humans, when in reality they are big babies and really only show aggression in females when protecting their young. They aren’t even poisonous, with very low toxicity rates. Rather then scrap it out, they would prefer to run away from human interaction. Lots of people that are familiar with the Huntsman spider and their capabilities are scared simply for the fact that they can run so fast and jump so far, along with their ability to move in any direction. I know that I have met people who would never travel to Australia simply for the fact that the Huntsman spiders live there and they are so big in size, along with some other pretty intimidating animals that Australia hosts.
Spiders have been mentioned all over the world throughout our entire history. They have represented mischief, patience, malice, creation and persistence. However when mentioned, usually the first thing that comes to mind is fear. They have made appearances in pop culture, television and Hollywood, music, and mythology, both ancient and modern myths. Overall spiders generally have a bad reputation, even though they contribute a lot to the health and balance of our natural world.