Giant rat-sized spiders that feed on fish return to the UK with 10,000 breeding females

22 August 2024, 14:15

The Fen Raft Spider is back in the UK in great numbers after a successful project to save them from extinction
The Fen Raft Spider is back in the UK in great numbers after a successful project to save them from extinction. Picture: Alamy
Alice Dear

By Alice Dear

The Fen Raft Spider is expected to have its best year on record after conservation work to increase the numbers of this once almost extinct species.

Listen to this article

Loading audio...

A spider species known for growing as large as a rat and feeding on fish is set to return to areas of the UK in huge numbers with an estimated 10,000 breeding females on the loose.

We're of course talking about the Fen Raft Spider, a large brown arachnid that can grow to the size of man's hand and spins webs of up to 30cm.

It is the biggest species of spider found in the UK (out of the 660) and eats anything from dragonflies to small fish and tadpoles, which they hunt as they run across water.

The Fen Raft Spider is back in such vast numbers after conversation work by the RSPB and Chester Zoo who have helped the spiders back from the edge of extinction.

The Fen Raft Spider can grow as large as a rat and feeds on fish
The Fen Raft Spider can grow as large as a rat and feeds on fish. Picture: Alamy

In 2010, the project was created to breed the spider species and later release them in the wild, in habitats more suitable for them to live. Two years later, the RSPB released the Fen Raft Spiders to Cantley Marshes and since then they have spread to surrounding areas, mostly around Norfolk and Suffolk.

The Fen Raft Spider lived for hundreds of years in the wetlands of the UK, however, during the industrial revolution many of their habitats were destroyed and by the 20th Century they were almost extinct.

While people who have a phobia of spiders won't be happy to hear this news, experts have reassured the public that they are not venomous and prefer to live in marshy areas - in other words, not in your home!

The Fen Raft Spider is not venomous and is mostly found in the wetlands of the UK
The Fen Raft Spider is not venomous and is mostly found in the wetlands of the UK. Picture: Alamy

Tim Strudwick, the reserves manager for the RSPB in Norfolk said on the project: "We just don’t know how far they are going to spread and that’s what’s exciting, seeing which bits of habitat they take over next."

He went on: "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.”