The spider species has had its largest mating season on record in the UK
TENS of thousands of giant spiders the “size of your hand” which can run across water have invaded the UK.
Chester Zoo has released thousands of Fen raft spiders after the species had its “biggest mating season on record”.
The Dolomedes plantarius or Fen raft spider can grow to the size of a person’s hand
Arachnophobes may be terrified to hear that there are currently more than 10,000 breeding females with this number having the potential to rise.
The all time high for the arachnid in the UK has been seen as a victory for the zoo with the species found to be in terminal decline a decade ago.
Fen raft spiders are semi-aquatic and they have the ability to run across the surface of water to catch their prey.
Their legs are covered in tiny hairs that detect the slightest of vibrations on the water’s surface allowing them to actively hunt, rather than rely on building webs.
Chester Zoo said: “Ten years ago we helped release thousands of giant spiders back into the UK!
“The Fen Raft Spiders were bred right here at the zoo, and we’re super happy to report there are now more than 10,000 breeding females and they’ve just had the biggest mating season on record!”
While they may look scary the fen raft spider is harmless and plays a vital role within healthy aquatic ecosystems, the zoo said.
The wildlife charity also explained that the species can “grow to be the size of your hand” meaning “you can’t miss them”.
Their diet includes other spiders, damselflies, dragonfly larvae and pond skaters, and they will even catch fish and tadpoles.
However, 15 years ago, the species almost became extinct after the destruction of its wetland home.
In order to save the species, the zoo set about rearing hundreds of baby spiders in individual test tubes as part of a collaborative conservation breeding rescue programme in partnership with the RSPB.
The RSPB estimate there are 10,000 breeding females across the UK – the best year on record.
Chester Zoo said: “Our team delicately hand fed tiny flies to each of the hundreds of spiderlings using tweezers, day in, day out, for weeks on end in our bio-secure breeding facility.
“Eventually, the young spiders grew strong enough to be returned to their natural habitat, which our partners worked to restore, and we released them in their hundreds!”
Many have been quick to respond to the announcement by Chester Zoo on X, formerly known as Twitter, with a mixed reaction.
One user commented: “Crikey! Hope they don’t come into homes.”
Another said: “Fantastic news! I’d love to see them up close.
“Maybe one day, hopefully!”
Someone else put: “Is there any way at all you can post about this with literally any other image??
“Very arachnophobic here.”
A fourth wrote: “Wow, not sure how I’d feel if I came across one of those – where exactly were they released?”
RSPB Mid Yare nature reserves site manager, Tim Strudwick, said: “The Fen Raft Spider is one of the UK’s rarest invertebrates and we are proud of the role our reserves and teams have played in its recovery.
“These spiders have an important role in maintaining the rich aquatic diversity found in the grazing ditches on our reserves. The females are impressive in size, but also beautiful – they are truly special to see!”