Spiders come in all shapes and sizes, from the tiny jumping spider to the giant bird-eating Goliath spider. While there are over 47,000 known spider species, some stand out as particularly rare finds for arachnologists and nature enthusiasts. Here’s an overview of some of the rarest, most elusive eight-legged creatures on the planet.
Defining Rarity
Rarity in the spider world can be defined in a few key ways:
– Limited geographic range – Found only in certain remote areas.
– Ultra small population – Teetering on the brink of extinction.
– Newly discovered – Just unveiled and documented by scientists.
– Unique traits – Possess distinctive features unlike other spiders.
Some spiders check multiple boxes, making them exceptionally uncommon discoveries. Next, let’s highlight some of these remarkable rarities.
Gooty Sapphire Ornamental Tarantula
The Gooty sapphire ornamental tarantula (Poecilotheria metallica) stakes its claim as one of the rarest spiders on Earth. This tarantula subspecies is found exclusively in a tiny forest region of Andhra Pradesh state in central southern India.
| Scientific Name | Poecilotheria metallica |
|---|---|
| Range | Andhra Pradesh, India |
| Estimated Population | Less than 200 left in the wild |
| Size | Up to 6 inches legspan |
| Distinguishing Features | Vibrant blue abdominal coloring, ornate metallic chevron patterns |
First discovered by arachnologist Rajesh Sanap in 1899, the Gooty sapphire tarantula’s population was estimated at only around 100 individuals as of 2001. Captive breeding programs have helped boost numbers, but habitat loss places this flashy spider at high risk of extinction.
Skeleton Tarantula
The skeleton tarantula (Ephebopus murinus), also known as the burgundy skeleton tarantula, is a rare find originating from the tropical forests of French Guiana, Suriname, and northern Brazil. Named for its dark leg striping over a pinkish-orange body, it has an especially tiny worldwide population.
| Scientific Name | Ephebopus murinus |
|---|---|
| Range | French Guiana, Suriname, northern Brazil |
| Estimated Population | Less than 2,000 worldwide |
| Size | 3-4 inch legspan |
| Distinguishing Features | Skeletal black and white leg markings, orange/pink coloring |
Skeleton tarantulas are solitary creatures that inhabit deep burrows rather than spinning webs to catch prey. Their scarcity makes them highly sought after by tarantula collectors, despite their aggressive tendencies. More inventory monitoring will be needed to ensure the species persists.
Assamese Jumping Spider
The Assamese jumping spider (Paracyrba wanlessi) stakes its claim as one of the tiniest known spiders in the world. First documented in India’s Assam state in 2001, this rare species has an average body length of just 0.6-0.65 mm.
| Scientific Name | Paracyrba wanlessi |
|---|---|
| Range | Assam, India |
| Estimated Population | Unknown, only a few specimens collected |
| Size | 0.6-0.65 mm body length |
| Distinguishing Features | Tiny size, enlarged anterior medial eyes |
This miniscule jumper’s conservation status remains uncertain. With more habitat loss expected across Assam, the species’ limited range could spell trouble. Much remains unknown about the behavior and habitat preferences of these teeny hoppers.
Darwin’s Bark Spider
In Madagascar, a little-documented web spinner with a massive spinning sheet was unveiled in 2009. Darwin’s bark spider (Caerostris darwini) gained fame as its silk was found to be the strongest biological substance ever studied.
| Scientific Name | Caerostris darwini |
|---|---|
| Range | Madagascar |
| Estimated Population | Unknown, but range is restricted |
| Size | 1.5 inch body length |
| Distinguishing Features | Huge orb webs up to 82 feet across, super strong silk |
These sizable spiders build their elaborate webs spanning rivers, streams and lakes across central and northern Madagascar. While C. darwini’s conservation status has not been evaluated, its limited island range points to rarity. Fewer than 30 individual spiders have been sampled to date. Deforestation could threaten its obscure habitat.
Ladybird Mimic Spider
Oneparticularly obscure spider mimics a more common bug. The ladybird mimic spider (Eresus sandaliatus) is found across parts of Europe and North Africa. As its name suggests, its black-spotted red appearance imitates ladybird beetles as a form of protection.
| Scientific Name | Eresus sandaliatus |
|---|---|
| Range | Europe, North Africa |
| Estimated Population | Unknown |
| Size | 5-7 mm body length |
| Distinguishing Features | Ladybird-like appearance, velvet-like coat of setae |
Beyond its unusual looks, the ladybird spider has an intriguing lifestyle. It’s one of very few spider species known to be actively social. Females cooperate in building communal webs where they dwell together. While not globally threatened, these spiders have experienced marked declines across Europe. Protecting habitats like dry grasslands and heathlands will be key.
Assassin Spiders
There are over 2,300 documented species of assassin spider, yet most remain highly elusive. These stealthy predators, also called pelican spiders, allure and attack prey using an extendable “neck” topped by a set of jaws.
| Estimated Species | Over 2,300 |
|---|---|
| Key Range | Found on all continents except Antarctica |
| Estimated Populations | Most species are rare, even new discoveries |
| Size | Most under 7 mm long |
| Distinguishing Features | Neck-like structure with jaws for grabbing prey |
While assassin spiders live in a diverse array of habitats worldwide, very little is known about most species. Specimens are infrequently encountered, even by researchers specializing in collecting spiders. Their cryptic lifestyle makes assassin spiders a challenge to find and study.
Micro Cave Obligate Spider
Newly described in 2021, the micro cave obligate spider (Varacosa parthenos) has been branded Florida’s “lost spider.” This critically endangered species has so far only been documented in two north Florida caves.
| Scientific Name | Varacosa parthenos |
|---|---|
| Range | Two caves in northern Florida |
| Estimated Population | Less than 20 individuals observed |
| Size | Approximately 5 mm body size |
| Distinguishing Features | Troglobitic – bound to humid cave habitat |
This elusive spider’s status as a troglobite – a creature adapted for humid cave dwellings its entire life cycle – makes it incredibly vulnerable. With such a small known population and range, it ranks among North America’s most endangered spiders. Protecting its delicate cave ecosystems is crucial.
Rare Australian Jumping Spiders
Island continents like Australia harbor numerous endemic spiders found nowhere else on Earth. Several jumping spiders restricted to southeastern Australia stand out for their tiny ranges.
The Key’s jumping spider (Opisthoncus keyserlingi) and the pygmy jumper (Mopsus mormon) only inhabit a narrow coastal region near Sydney. Each occupies patches of natural bushland which are rapidly declining.
Meanwhile, Hickman’s jumper (Euophrys hickmani) clings to existence in periodically wetted riparian habitat in Victoria’s Grampians National Park. Fewer than 10 specimens have been collected as of 2020. Loss of its precarious wetland ecosystems could doom the species.
Protecting small pockets of specialized habitat will be key to these jumping spiders’ survival. Their limited ranges and dependence on unique niches make them inherently prone to rarity and extinction risks.
Conclusion
While the rarest spiders hail from an array of families, they share common traits like small population sizes, highly specific micro-habitat needs, and restricted ranges that make them vulnerable. From tiny subterranean blind spiders to ancient relictual captors like assassins, these extraordinary rarities highlight the immense diversity of arachnids still being uncovered by science. Conserving specialized pockets of habitat will be crucial to ensuring their secrets are not lost before they can be fully revealed and appreciated.