Arachnophobia is one of the most common fears people have. Even the smallest, harmless house spiders can evoke a shriek of terror. If that’s the case for you, might as well close this page right now because I’d like to introduce you to Theraphosa blondi, also known as the goliath birdeater, officially recognized as the world’s largest spider.
Okay, just kidding about the leaving part. This is a safe space, I promise. Besides, despite its menacing size and huge fangs, the goliath birdeater is quite harmless to humans unless you have a specific allergy. Although its fangs pack venom, as most spiders do, it doesn’t hurt more than a wasp sting.
Now that we’ve got that out of the way, let’s dive deep into the fascinating world of this South American tarantula.
A tarantula as big as a dinner plate that can eat an opossum
Let’s start with the most conspicuous item on the menu: size. T. blondi‘s body size can reach up to 12 centimeters (about 5 inches), and if you add its leg span it measures up to 28 centimeters (11 inches). It weighs up to 170 grams (6 ounces). If you were to have a tarantula dinner, it would occupy the entire plate.
Speaking of which, Rick West, one of the world’s foremost tarantula experts, actually ate one while out in the Amazon. This exotic meal was prepared by the local Piaroa people using a special cooking technique and recipe. According to West, the spider’s muscles taste like prawns while the abdominal contents, which are hard-boiled in a rolled leaf, taste gritty and bitter. As a proper way to finish this gruesome meal, it’s traditional to use the spider’s two-centimeter-long (three-quarter-inch) fangs as toothpicks.
Going down the food web, as for what the goliath birdeater likes to eat, birds are surprisingly rare on the menu. Its ‘birdeater’ nickname is a misnomer that can be traced to an 18th-century engraving depicting another tarantula from a different species eating a hummingbird.
Rather than birds, which are highly difficult to catch, T. blondi prefers to devour insects and worms. But when the opportunity presents itself, this tarantula won’t shy away from eating relatively large animals such as frogs, lizards, and other amphibians. Some individuals are quite bold and may go for even larger prey. During one night in the Peruvian jungle, Michael Grundler of the University of Michigan witnessed with his very own eyes how a goliath birdeater killed and started eating a mouse opossum (Marmosa murina).
“The opossum had already been grasped by the tarantula and was still struggling weakly at that point, but after about 30 seconds it stopped kicking,” Grundler said. “We were pretty ecstatic and shocked, and we couldn’t really believe what we were seeing.”
The spider didn’t catch the possum in a web. That would have been quite the sight. Instead, like all tarantulas, T. blondi leaps onto unsuspecting prey and uses its large fangs to bite and kill.
That’s not to say that T. blondi doesn’t produce and use silk. The tarantula lives in shallow burrows beneath the forest floor, which it lines with ultra-strong silk to enhance the stability of the structure.
Tiny hairs like a hail of arrows
This shelter is important for both hunting and escaping its own predators. After all, in the Amazon jungle, many dangers lurk. If a predator tries to attack T. blondi, it has its trusty fangs to help it fight back. But first, the tarantula employs its first line of defense consisting of urticating hairs that line its abdomen.
These tiny harpoon-shaped hairs are very irritating and itchy, and can be fatal to smaller mammals like mice that inhale them. T. blondi simply has to rub their legs on their abdomen to release a hail of these sharp hairs into the air, which inflict massive damage. When rubbing the hair together, the giant tarantula also produces a loud, hissing noise that can be heard from 4-5 meters (15 feet) away. The sound can sometimes deter predators, scaring them away.
Goliath birdeaters also have an intriguing reproductive pattern. After breeding, females will lay anywhere from 50 to 200 eggs in a giant sac spun from silk. For good measure, the tennis ball-sized sac is covered in the itchy hairs to keep predators away. The momma goliath will carry her sac everywhere she goes to make sure her offspring are protected, a unique feature among tarantulas. Rather than being fertilized internally, these eggs are fertilized by sperm collected from mating after they pass out of her body.
The younglings hatch 6 to 8 weeks after the eggs were laid, but it will take another two to three years before they reach sexual maturity, a mighty long time for a spider. During this time, the spiderlings can be expected to molt five or six times as they develop, shedding their old exoskeletons in the process and emerging in a new, larger one each time.
Females can live up to a staggering twenty years, but males usually don’t make it past three years of age, often dying soon after mating. That’s not a tragedy for the female. Goliath birdeaters are nocturnal solitary creatures that only come together to do the deed once in a blue moon.
Some claim that the giant huntsman spider (Heteropoda maxima) is, in fact, the world’s biggest spider. This is indeed a formidable arachnid, whose twisted legs can stretch to a span of 30 centimeters (almost 12 inches). Perhaps there are individuals of this strange spider, which walks like a crab and can only be found in a cave in Laos, that may be larger than the goliath birdeater. However, for now, the Guinness World Records recognizes T. bondi as the largest spider. Besides, the goliath is a lot chunkier than the huntsman. It’s like “comparing a giraffe to an elephant,” Piotr Naskrecki, an entomologist and photographer at Harvard University’s Museum of Comparative Zoology, told Live Science.
The goliath birdeater is considered to be quite common and not endangered. However, it is very shy.
“I’ve been working in the tropics in South America for many, many years, and in the last 10 to 15 years, I only ran across the spider three times,” Naskrecki said.
So I guess that’s good news for your nerdy arachnophobes.