It is time to say goodbye to an epic survivor. The longest-lived spider ever recorded posthumously smashed her way into the record books, despite having been slain by her mortal enemy last year. Where the previous record-holder was just 28, the female Gaius villosus, a type of trapdoor spider, was 43 when she died.
Most classes of animals live longer in captivity than in the wild, but trapdoor spiders are not popular pets. The individual in question lived in the Western Australian Wheatbelt, known only as Number 16. Number 16 was recorded by “Lady of Spiders" Dr Barbara York Main as a new hatched spiderling in 1974 in the first year of a groundbreaking annual study of spider populations in the area.
York Main recently retired, but Leanda Mason, a PhD student at Curtin University is keeping the study going, telling IFLScience that York Main "inspidered her". After recording the recent death of Number 16 at the ovipositor of a parasitic wasp, Mason realized the victim's impressive age, and published a report in Pacific Conservation Biology.
“Through Barbara’s detailed research, we were able to determine that the extensive lifespan of the trapdoor spider is due to their life-history traits, including how they live in uncleared, native bushland, their sedentary nature, and low metabolisms,” Mason said in a statement.
Like other trapdoor spiders, Gaius villosus establish a burrow and only leave under the most extreme circumstances. Mason told IFLScience they wait at the mouth of the burrow at dawn and dusk until a passing insect or even small lizard triggers the lines they lay around their burrow, at which point the spider pounces.
At other times they live in their burrows, which remain cool and humid even in the fierce summer heat. Some species have trapdoors that fit so snugly they can keep out floods. It's not a very demanding lifestyle. Indeed, Mason said, it is the cool burrow conditions that make them such attractive prey for the wasps, increasing the chance the parasitic egg will hatch.
Males have shorter life expectancies, Mason explained, leaving their burrows at 5-7 years old to search for mates, and dying soon after. Mason expects that, on a complete examination of the data, she will find other venerably aged females, but has not yet done so.
As it lives in such a remote location, the species is not well enough studied to know if it is potentially dangerous to humans, but there is no record of any harm. The same cannot be said in reverse, however. “The WA Wheatbelt has been 97 percent cleared,” Mason told IFLScience. Invertebrates are so understudied it is hard to get the data to have them included on the official list of endangered species, but Mason thinks Gaius villosus would qualify.