An adult Desertas wolf spider in the wild © Emanuele Biggi
Keepers at Bristol Zoo Gardens are rejoicing the hatching of over 1,000 Desertas wolf spiderlings, one of the rarest species of spider in the world.
The tiny spiderlings are currently only four millimetres in diameter, but will grow to be up to 12 centimetres in size (including legs).
This breeding programme is a world first as this species has never been bred in captivity before.
“Because this was the first time this species had ever been taken into captivity to breed, it was a steep learning curve,” says Mark Bushell, curator of invertebrates at Bristol Zoo.
“After some of the female spiders were mated, it was an anxious wait to see if they would produce egg sacs. We were thrilled when they did, and to see the tiny spiderlings emerge was fantastic – a real career highlight.”
An adult female Desertas wolf spider with young on her back © Bristol Zoo Gardens
The Desertas wolf spider is listed as Critically Endangered on the IUCN Red List, and is found in only one valley on one of the Desertas islands, near Madeira, Portugal.
In 2016, Bushell and a team of conservationists visited the islands to collect 25 of the spiders to try and breed at the zoo.
A conservation strategy is being developed by Bristol Zoo, the IUCN and the Instituto dast Florestas e Conservação de Natureza (IFCN) to prevent the species becoming extinct.
There are thought to be only 4,000 adult spiders in the wild, and it is hoped that some of the captive-bred spiderlings can be returned to help boost these numbers.
Hundreds of spiderlings will also be sent to other zoos in the UK and in Europe to create an international breeding programme.
Mark Bushell with a Desertas wolf spiderling © Bristol Zoo Gardens
“Establishing the world’s first captive breeding programme for this species is a fantastic step towards protecting it for the future,” says Bushell. “Now we have successfully created a ‘safety net’ population here at Bristol Zoo to help safeguard this impressive creature for the future.”