US red swamp crayfish introduced to Spain in 1973 now impossible to eradicate

In 1973, Spain introduced red swamp crayfish from Louisiana, US, hoping they would help farming. However, more than 50 years later, the invasive species has become impossible to eradicate, Hindustan Times reported. The crayfish could walk across dry land, dig tunnels over three feet deep, and survive severe drought conditions. They also ate underwater vegetation, reducing food for native fish.