While exploring a forest in Guyana at night, the entomologist Piotr Naskrecki found himself face to face with a monstrous arachnid. It was a Goliath spider, known as the largest spider in the world.
Venturing into a tropical forests can sometimes lead to impressive discoveries, and Piotr Naskrecki would certainly agree. This entomologist from the Museum of Comparative Zoology at Harvard University has a habit of going out into the field to observe insects in their natural environment. But one day, the exploration took an unexpected turn, as the researcher stated on his blog.
A few years ago, while exploring the rainforest in Guyana at night, Piotr Naskrecki heard a strange noise. 'I was listening to the sounds of the night in complete darkness when I heard the sound of an animal running, and I could clearly hear its paws hitting the ground and the dry leaves bending under its weight,' the entomologist says. He expected to see a small mammal, an opossum or a rat but that was not the case.
'When I turned the flashlight on, I had trouble understanding what I was seeing,' he continued. The brown, hairy creature actually resembled a rat but a second glance quickly confirmed that it was not a rodent. The body that had eight legs became clear, it was a Goliath spider.
The biggest in the world
The Goliath spider, also known as Goliath birdeater (Theraphosa blondi) is an arachnid with impressive dimensions. Its legs can extend to over 11 inches, the 'length of the forearm of a child,' and its body is as wide as a 'big fist' according to Piotr Naskrecki as he said to LiveScience. Mass wise, the spider can reach up to 170 grams, as much as a 'young puppy.'
Unsurprisingly, these measurements give the Goliath spider the title of biggest spider in the world by the Guinness World Records. 'Because of its gargantuan size, the spider is probably the only one in the world that makes noise when it moves, its legs have hardened ends and claws that make a very distinct clicking sound,' the scientist claims on his blog.
But this is not the only sound that this reputedly aggressive spider makes. When Piotr Naskrecki approached the specimen, it began to rub its hind legs against his abdomen. 'My first thought at seeing this adorable behaviour was "Oh how cute!" until a cloud of stinging hairs flew towards my eyes, making them itch and water for several days,' he explains. An adorable behaviour, which is apparently becoming less and less commonplace as spiders have seen an observable difference in their level of aggression by scientists.
The Goliath spider is particularly good when it comes to defending or attacking. The stridulation observed by the entomologist is usually a first warning. Then the spider bombards the intruder with stinging bristles that are supposed to dissuade him from getting any closer. For Piotr Naskrecki, this was obviously enough to scare him off but the arachnid pulled out his other weapon, fangs almost an inch long.
As a venomous spider, the Goliath birdeater produces a neurotoxic substance but it is not fatal to man. On the other hand, its big and powerful fangs can deliver a painful bite. This 'feels like digging a fingernail into your hand,' says the entomologist. But even if it bites you, 'a chicken could probably cause more damage,' he says. So you see, no need to be afraid of them!
According to a 2005 study, the gargantuan sized Goliath spider, who is only active at night, has in fact a slower metabolism than its 'cousin' species which allows it to reduce its oxygen requirements. All in all his immense body allows him to tackle larger sized prey.
Anything it can get its hands on
Despite its nickname 'bird-eater,' the Goliath spider does not really feed on birds. However, it is capable of catching and killing small mammals, including rodents, frogs and sometimes larger insects. 'It will essentially attack everything it encounters,' says the entomologist.
According to Naskrecki, its main prey is nevertheless earthworms, who come out from the ground as soon as it is a little wet. 'Earthworms are very nutritious,' he adds. Although the lifespan of females exceeds 10 years, Goliath spiders are not that common. After more than 15 years of exploring the forests of South America, Piotr Naskrecki has only encountered three.
'Two or three years after my first meeting with the Goliath spider, I was back in South America, walking alone at night in the rainforest of Suriname when my foot suddenly grazed something big and alive and I almost tripped. I froze, expecting a snake, but it was just another Goliath spider' he concludes.