3 Cool Spider Facts
Spiders are fascinating critters. More than they are often given credit for. If you want to learn three cool facts about spiders, read on!
1. The longest-lived spider was 43 years old
And she didn’t even die of old age!
Her “name” was Number 16, and her burrow was marked back in 1974. In 2016, the researchers who were in charge of this long-term study site found the burrow of Number 16 vandalized. By a parasitic wasp no less!
In 1974, Barbara York Main, a famous arachnologist, initiated a long-term study into the spiders in the area. An area of South Western Australia which had been cleared for agriculture. Clearing that left only 7% of its native vegetation.
An area of 26 m by 40 m was delineated, and all spider burrows found were marked. Then, over subsequent years, scientists went back to study the state of the burrows and spiders living within.
This is possible as spiders never change their burrows. Although males abandon their burrows once they are sexually mature (at about five years old), they die soon after. Females, on the other hand, remain at their burrow and never leave (as they are almost blind and would be very susceptible at the surface).
Between the burrow fidelity, the presence of wasp marks & the absence of a spider, and the fact that the researcher had seen Number 16 alive in her burrow just 6 months ago, the researchers were extremely confident that Number 16 had indeed died.
2. Not all spiders have eight eyes
Some have no eyes at all!
The first eyeless spider was described in 1847. This Slovenian spider, by the name of Stalita taenaria, literally has no eyes!
The record of having zero eyes is shared by more than 1,000 spiders worldwide. These eyeless spiders inhabit caves and other subterranean habitats around the world.
But are eight eyes the most eyes a spider can have? Yes. It is also the most common number of eyes in spiders. Interestingly, once a scientist thought they had found a spider with sixteen eyes!
The species Troglohyphantes polyophthalmus was originally described in 1881. It was described based on a spider killed during an early stage of moulting, so it appeared that it had sixteen eyes instead of eight.
3. There is a bioluminescent spider
It’s a jumping spider, of course!
Cosmophasis umbratica can be found from India to Indonesia. This Asian spider has the ability to both reflect ultraviolet (UV) and to see UV too.
Interestingly, males and females do not have the same UV abilities.
Males of C. umbratica have markings on their bodies which reflect UV. Meanwhile, females fluoresce green when exposed to UV. Their complementary bioluminescent abilities are crucial for the successful mating of these spiders.
UV spectrums of light are naturally present in the sunlight Earth receives. While we are not able to perceive it, many animals can. Scientists tested the ability of these spiders to see UV, and its importance to mating, by comparing spider matings under normal light versus spider matings while using a transparent filter that blocked UV wavelengths.
Without their respective UV abilities, both females and males basically ignored each other.
