huge snails in river!

huge snails in river!

Observation - huge snails in river! - UK and Ireland. Description: doing some litter picking with my local conservation group and found these huge, obviously non native, snails in the water, they were both dead. we assumed they were dumped from a fishtank but if anyone can identify them it would be nice to know what they

doing some litter picking with my local conservation group and found these huge, obviously non native, snails in the water, they were both dead. we assumed they were dumped from a fishtank but if anyone can identify them it would be nice to know what they are.