The sheer size of some spiders can spark both fascination and apprehension. Many people wonder which spider holds the record for being the largest. Exploring the world of giant arachnids reveals remarkable creatures that have adapted to various environments, showcasing impressive dimensions.
Measuring Spider Size
Determining the “biggest” spider involves specific measurement criteria. Scientists commonly use two primary metrics: leg span and body length, with weight also playing a role. Leg span is typically measured diagonally from the tip of the first leg on one side to the tip of the fourth leg on the opposite side. Body length refers to the measurement from the spider’s head to the end of its abdomen, excluding the legs. Different species might excel in one measurement over another, leading to varied contenders for the “biggest” title.
The Goliath Birdeater
The Goliath Birdeater, Theraphosa blondi, is recognized as the largest spider in the world by mass and body length. Found in the rainforests of northern South America, this tarantula can weigh up to 175 grams (6.2 ounces), comparable to a small puppy or a hockey puck. Its body can reach up to 13 centimeters (5.1 inches) in length, roughly the size of a human fist. The leg span can extend up to 30 centimeters (12 inches), about the size of a dinner plate.
Despite its name, the Goliath Birdeater rarely preys on birds in the wild. Its diet primarily consists of large arthropods, worms, amphibians, and small terrestrial vertebrates like rodents, frogs, and lizards. This nocturnal hunter lives in silk-lined burrows beneath rocks and roots in humid, swampy forests. While their fangs can break human skin, their venom is not considered dangerous to humans, with effects often compared to a wasp sting. As a defense mechanism, they rub their abdomen with their hind legs to release irritating, barbed hairs.
Other Impressive Arachnids
While the Goliath Birdeater holds the record for mass, other spiders are notable for their impressive dimensions. The Giant Huntsman Spider, Heteropoda maxima, found in Laos, is considered the world’s largest spider by leg span, reaching up to 30 centimeters (12 inches). Its body length is about 4.6 centimeters (1.8 inches), and it weighs around 167 grams (5.9 ounces), making it slightly lighter than the Goliath Birdeater. Huntsman spiders do not build webs for hunting but actively pursue their prey with incredible speed, moving up to a meter per second. Their legs are twisted, allowing them to move in a crab-like fashion.
The Brazilian Salmon Pink Birdeater, Lasiodora parahybana, is another large tarantula, with females weighing over 100 grams and reaching a leg span of up to 28 centimeters. This species is known for its distinctive salmon-pink hairs. The King Baboon Spider, Pelinobius muticus, and the Colombian Giant Tarantula, Megaphobema robustum, also rank among the largest, with leg spans potentially exceeding 20 centimeters. These species demonstrate the diversity of large arachnids.
Common Misconceptions About Large Spiders
Many misunderstandings surround large spiders, often fueled by exaggerations in popular culture. A common myth suggests that people swallow spiders in their sleep, but this is highly unlikely due to environmental factors and a spider’s natural avoidance of large, noisy creatures. Another misconception is that all spiders are aggressive and actively seek to bite humans.
In reality, spiders are generally timid and will only bite if they feel threatened, such as when accidentally stepped on or squeezed. Some believe that certain spiders, like the Daddy Long-legs, are the most venomous but cannot bite humans due to short fangs. This is false; their fangs are not too short, but their venom is not dangerous to humans. Additionally, not all spiders spin webs; many, like the huntsman spiders and wolf spiders, are active hunters. These common myths often create unnecessary fear and misrepresent the actual behavior and characteristics of even the largest spider species.