In English, the only names for this mark are 'the at sign' or, sometimes, 'the commercial at sign', as the answers above indicate. It has the latter name because it is often used in business in sentences such as: "14 items @ �12.50 = �175.00.
There simply is no other name in this language. The French, apparently, call it an 'arobase', but that's of little use to you unless you live in France or Quebec! The Dutch, apparently, call it a monkey's tail! However, I guess you're not in Holland either.