More than 100 crayfish which are threatened by a more aggressive American species have been rescued from a Leicestershire pond.

The native European white-clawed crayfish were in danger from the foreign breed which also carries a virulent disease.

Rescuers have now put the animals in a "hospital" tank to protect them from the North American signal crayfish.

The endangered crayfish were fished from a pond near Loughborough and will be reintroduced to a secure waterway.

The local breed

The operation is thought to be the first of its kind in the UK.

Fears for the safety of the endangered species began after a number of North American signal crayfish took up residence in the pond, threatening their native cousins.

The larger and more aggressive creatures were either illegally introduced into the wild or escaped from crayfish farms and ponds.

An Environment Agency spokesman said they had been been farmed in Britain for restaurant food and had been escaping since the 1970s.

Signal crayfish often walk overland in their search for a home and are known to colonise freshwaters, killing or displacing native crayfish.

They are also blamed for damaging river banks.

The introduced crayfish carry a virulent disease, known as crayfish plague, which can spread rapidly among more vulnerable native species.

Once the rescued crayfish are confirmed as being free from disease, they will be relocated to a secure pond, free of the threat from the alien species.