More than 1,000 young spiders from a hybrid species have been released into the Suffolk broads.
The Dolomedes plantarius spiderlings were released into suitable dykes at Castle Marshes between Lowestoft and Beccles on Wednesday.
About 4mm, they are hybrids between species found in Sussex and Suffolk.
The 1,600 spiderlings were hand-reared in the kitchen of project leader Dr Helen Smith, with the surplus reared at the John Innes Centre in Norwich.
Dr Smith said: "The hybrids bring the advantage of increased genetic variability to the new population.
"This... should give the new population at Castle Marshes the best potential to adapt to its surroundings and to cope with the impacts of climate change."
The project was organised by Natural England and Suffolk Wildlife Trust and was aided by a grant from the BBC Wildlife Fund.