Spiders, with their diverse forms and behaviors, often spark curiosity, particularly concerning their size. While many are small, some species reach impressive scales. Exploring the largest spiders on Earth reveals a fascinating aspect of arachnid biology, highlighting the remarkable adaptations these creatures have developed.
Defining “Largest”
The term “largest” when applied to spiders can refer to different measurements, primarily leg span or body mass. A spider with the greatest leg span might not be the heaviest, and vice versa.
Leg span measures the distance from the tip of the longest leg on one side to the tip of the longest leg on the opposite side. Body mass, or weight, focuses on the spider’s bulk and overall volume.
Giants of Leg Span
The Giant Huntsman Spider, Heteropoda maxima, holds the record for the longest leg span among all known spiders. Discovered in a cave in Laos in 2001, this species can boast a leg span of up to 30 cm (11.8 inches), roughly the size of a dinner plate. Its body, by comparison, is relatively flat and measures about 4.6 cm (1.8 inches) long.
This spider’s coloration is typically yellowish-brown, often with dark spots on its rear section and dark bands on its legs. Unlike many spiders, the Giant Huntsman does not build webs for hunting, instead actively pursuing its prey with remarkable speed and agility. It relies on its large, strong legs to pounce on insects, small rodents, and reptiles, injecting them with venom. They are primarily nocturnal and prefer to live in dark, warm environments like limestone caves, often near entrances rather than deep inside.
Giants of Body Mass
The Goliath Birdeater, Theraphosa blondi, is widely recognized as the heaviest spider in the world. This tarantula can weigh up to 175 grams (6.2 ounces), comparable to a small puppy or a regulation pocket billiards ball. Its body length can reach up to 13 cm (5.1 inches), about the size of a human fist, and its leg span can extend up to 30 cm (12 inches).
The Goliath Birdeater is typically tan to light brown with a hairy body, including stinging hairs that it can flick as a defense mechanism. It inhabits the humid rainforests of northern South America, particularly in countries like Suriname, Guyana, French Guiana, and Brazil. These spiders are terrestrial and nocturnal, often living in deep burrows they either dig themselves or take over from other animals. Despite its name, the Goliath Birdeater rarely preys on birds, with its diet primarily consisting of other large arthropods, worms, amphibians, and occasionally small rodents, lizards, or snakes.
Other Notable Large Spiders
Beyond the absolute record holders, several other spider species are notable for their impressive size. The Brazilian Salmon Pink Birdeater, Lasiodora parahybana, is another substantial tarantula, with a leg span that can reach up to 28 cm (11 inches). This species is native to the tropical rainforests of eastern Brazil, where it burrows on the forest floor. It is known for its distinctive reddish-pink hairs on its limbs and abdomen, which give it its common name.
The King Baboon Spider, Pelinobius muticus, is among the largest spiders in Africa. Found in the shrublands and grasslands of East Africa, including Kenya and Tanzania, it can achieve a leg span of up to 20 cm (8 inches). This tarantula has a rusty brown to orange coloration and is a burrowing species, using its thick hind legs for digging.
Another large tarantula, Theraphosa apophysis, also known as the Pinkfoot Goliath, is a close relative of the Goliath Birdeater. Found in Venezuela, Colombia, and Brazil, it can also reach a leg span of up to 30 cm (12 inches), though it is generally considered slightly less massive than T. blondi. Young T. apophysis spiders display pink shading on their leg tips, which fades as they mature.