48 Fun Facts About Spider

Spiders belong to which order?

Araneae is the order of spiders, with more than 50,000 described species placed in over 130 families worldwide.

Which is the only continent with no spiders?

Antarctica is the only continent with no spiders; every other continent has them, including a jumping spider recorded on Everest's slopes above 6,000 metres.

Unlike insects, spiders lack which sensory feature on their heads?

Spiders have no antennae; insects smell and feel with antennae, while spiders rely on sensory hairs and slit organs spread over their legs and body.

How do spiders extend their legs, since they have no extensor muscles?

Hydraulic pressure: spiders extend their legs by pumping hemolymph into them, since two leg joints have no extensor muscles; a dead spider's legs curl inward once that pressure is gone.

Which jumping spider was first reported in 2008 to feed mostly on plant matter?

Bagheera kiplingi, a Central American jumping spider, gets most of its food from protein-rich leaf-tip nubs grown by an ant-guarded tree; no other spider is known to eat mainly plant food.

Roughly how much prey do the world's spiders eat each year, according to one estimate?

A 2017 estimate put it at 400 to 800 million tons of prey a year, killed by a global spider population weighing about 25 million tons.

In which property does dragline spider silk beat both steel and Kevlar?

Toughness means energy absorbed before breaking; silk's stretchiness is what makes it so hard to snap.

Darwin's bark spider, discovered in Madagascar in 2009, holds what record?

Darwin's bark spider builds the largest orb webs ever found, slung across rivers on bridge lines up to 25 metres long with capture areas of up to about 2.8 square metres.

Which is the world's largest spider by mass and body length?

The Goliath birdeater, a tarantula of northern South America, is the heaviest spider, with a body up to about 13 cm long and a mass of up to around 175 grams.

Males of Patu digua, a Colombian contender for smallest spider, are about the size of what?

About a fifth of a pinhead: male Patu digua measure around 0.37 mm in body length, smaller than a grain of sand.

Which family, with about 7,000 species, is the largest of all, making up 13% of the order?

Salticidae, the jumping spiders, is the largest spider family with more than 6,000 described species; its members hunt by sight using large forward-facing principal eyes.

Which salticid genus is famous for eating its own kind and improvising hunting tactics?

Portia, a jumping spider that preys on other spiders, improvises tactics such as plucking a web to mimic struggling prey, and remembers which tricks worked.

The dancing peacock spiders of the genus Maratus are native to which country?

Peacock spiders are Australian; nearly all Maratus species live only in Australia, where males about 4 to 5 mm long raise coloured abdominal flaps and dance for females.

Which is the only species known to live almost entirely underwater?

The diving bell spider eats, mates and lays eggs inside an air-filled silk bell anchored to water plants, surfacing only to top up its oxygen supply.

Bolas spiders catch moths by doing what?

They lure male moths in with up to three fake sex pheromones, then reel them in like an angler.

What is the name for the way small spiders travel by releasing fine threads and riding the wind?

Ballooning: the spider releases silk threads that catch the wind or atmospheric electric fields and lift it off, which is how spiders have been found hundreds of kilometres out at sea.

Which two spiders are the only ones in North America with venom considered dangerous to people?

The brown recluse and the black widow are the only North American spiders whose venom is considered medically significant; recluse venom destroys tissue, widow venom attacks the nervous system.

How many eyes does a brown recluse have, unlike most spiders?

They sit in three pairs; the violin mark on its back is not a reliable identifier because other spiders have it too.

Black widows, redbacks and the New Zealand katipō all belong to which genus?

Latrodectus is the widow genus; its latrotoxin venom causes latrodectism, and its roughly three dozen species include South Africa's button spiders.

The Australian redback is one of a number of spiders that usually do what while mating?

Eat the male: during redback mating the male somersaults onto the female's fangs and is usually consumed, a sacrifice that lengthens copulation and raises his share of paternity.

After antivenom arrived in 1981, how many Sydney funnel-web deaths were recorded through 2021?

None: the 13 recorded deaths from Sydney funnel-web bites all came between 1927 and 1980; after the antivenom's 1981 release no fatality was recorded through 2021.

Who first described the Sydney funnel-web in 1877, naming it Atrax robustus?

Octavius Pickard-Cambridge, an English clergyman and arachnologist, named Atrax robustus in 1877; the species name robustus is Latin for sturdy.

Roughly how many tarantula species have been identified in the family Theraphosidae?

Over 1,000 tarantula species have been described, spread across well over 100 genera; New World species defend themselves by flicking irritating barbed hairs from the abdomen.

Wolf spiders carry their egg sacs how?

Attached to their spinnerets: a female wolf spider drags her round egg sac behind her, and once the young hatch they ride on her back for days.

Male giant huntsman spiders in Laos reach a leg span of about how much?

About 25 to 30 cm: Heteropoda maxima, described from Laotian caves in 2001, has the widest leg span of any spider, though heavier tarantulas outweigh it.

Which spider family has no venom glands, subduing prey with silk alone?

Uloboridae, the hackled orb-weavers, have no venom glands at all; they wrap prey tightly in silk and crush it before feeding.

Arachnophobia affects roughly what share of the world's population?

About 3.5 to 6.1% of people worldwide are estimated to have arachnophobia, one of the most common specific phobias, though very few spiders can harm a person.

In Ovid's Metamorphoses, the weaver Arachne becomes a spider after challenging which goddess?

Minerva (Athena): in Ovid's telling the Lydian weaver Arachne matches the goddess in a weaving contest, is struck in fury and, after hanging herself, is turned into a spider.

In E. B. White's Charlotte's Web, what is the first phrase Charlotte weaves to save Wilbur?

'Some Pig' is the first message Charlotte weaves in the 1952 book; 'Terrific', 'Radiant' and 'Humble' follow, and her full name, Charlotte A. Cavatica, echoes the barn spider's Latin name.

Little Miss Muffet, frightened away by a spider, was eating what?

Curds and whey: the rhyme, first printed in 1805 in Songs for the Nursery, has Miss Muffet eating the two on her tuffet when the spider sits down beside her.

Spiders' fangs are the final sections of which appendages?

Scorpions' chelicerae have three sections and no fangs; spiders' have two, folding away when not in use.

Which is the most primitive living group of spiders, lacking a fully centralised nervous system?

Mesothelae, the segmented trapdoor spiders of East and Southeast Asia, keep a plated abdomen and a less centralised nervous system; all other living spiders fuse every ganglion into one mass in the cephalothorax.

Which copper-based pigment carries oxygen in spider hemolymph?

Hemocyanin, a copper-containing protein dissolved in the hemolymph, carries oxygen in spiders; it turns faintly blue when oxygenated, unlike iron-based hemoglobin.

What are the sheet-like breathing organs found in tarantulas and other primitive spiders called?

Book lungs: stacked, leaf-like plates that exchange gases with the hemolymph; tarantulas and other mygalomorphs have two pairs, opening on the underside of the abdomen.

What is the narrow waist joining a spider's cephalothorax to its abdomen called?

The pedicel is the slender stalk between cephalothorax and abdomen; it carries the gut, nerve cord and aorta, and lets the abdomen swivel independently while spinning silk.

Which is more abundant and diverse: spiders that spin spiral orb webs, or those that make tangled cobwebs?

Cobweb spinners: spiders that build tangled, irregular cobwebs are more abundant and diverse than orb-weavers, even though the spiral orb web may be one of the earliest web forms to evolve.

Female spiders lay their eggs in what?

Silk egg cases: females wrap their eggs in a silk sac that may hold hundreds of eggs, and mothers of many species guard it or carry it with them.

Why do male spiders perform elaborate courtship rituals?

To avoid being eaten by the larger female: courtship signals identify the male as a mate rather than prey; males of most species survive a few matings, limited mainly by short lifespans.

Spider silk genes have been inserted into which organisms in the search for mass-produced silk?

Mammals and plants: spider silk genes have been expressed in goats, whose milk carried the silk protein, and in tobacco and potato plants, in the hunt for silk factories.

Which spider family are wolf spiders, named for their hunting prowess and excellent eyesight?

Lycosidae, from the Greek for wolf, hunt alone and mostly without webs, running prey down, pouncing on it or ambushing from burrows.

Which chelicerate group do spiders belong to, alongside scorpions?

Arachnids have two body sections and eight legs; ticks, mites and harvestmen are also arachnids.

The vegetarian salticid feeds on Beltian bodies, nutritious nubs produced by which trees?

It lives on Vachellia acacias in Mexico, Costa Rica and Guatemala, dodging the ants that guard them.

Which family of funnel weavers includes the hobo spider?

Agelenidae, the funnel weavers, spin flat sheet webs with a tubular retreat at one edge; the hobo spider and the giant house spider are members.

What is the especially fine silk that airborne spiders use to lift off called?

Gossamer is the especially fine silk spiders release to ride the wind; the word later came to mean any exceedingly fine thread or fabric.

Which family are the cellar spiders, the long-legged daddy long-legs of house corners?

Pholcidae are the cellar spiders; the common house species Pholcus phalangioides hangs in loose, tangled webs and whirls its body rapidly when the web is disturbed.

The world's heaviest tarantula lacks which structure found on most adult males' front legs?

Tibial spurs: males of Theraphosa blondi lack the tibial hooks most male tarantulas use to hold off the female's fangs while mating; the species burrows in rainforests of the Guianas and northern Brazil.

Which genus are the fishing spiders that run across water to catch prey?

Dolomedes, the fishing spiders, rest their front legs on the water surface to sense ripples, then run across it or submerge briefly to seize insects and small fish.

Besides the panther one, which two Kipling-named salticid genera did the Peckhams coin in 1896?

Akela and Nagaina, after the wolf leader and the cobra, were published by George and Elizabeth Peckham in 1896, along with Messua, in a monograph on Central American jumping spiders.