The Desertas wolf is one of the only spiders in the world to carry its babies on its back until they are mature enough to hunt for food themselves.
Around 1,000 of the venomous critters have been bred in captivity at Bristol Zoo Gardens in what is believed to be a world-first.
Experts even hand-reared some of the tiny arachnids from eggs because they are so rare.
They are classed at critically endangered and will now be exported to other zoos across Europe to extend the breeding programme.
The species is currently found in one valley on Desertas Grande, one of the Desertas islands near Madeira, Portugal.
Mark Bushell, curator of invertebrates at Bristol Zoo, travelled to Desertas Grande last year and collected 25 Desertas wolf spiders to breed.
He said: “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.”
He added: “They carry babies on their back as a form of protection to them, and also when they’re ready to leave “home” they can drop off the female at opportune moments while she’s moving around the habitat, thus allowing them to disperse effectively.”
The spiders stay on their mother’s back for around a week before venturing out to feed on their own.
They will eventually grow to around 12cm is size and be capable of giving humans a painful and venomous bite, which would not be fatal.