mottled ducks?

[Jededia]

I live in Karachi (Pakistan) a few months a go I purchased a pair of ducklings, when they grew up i searched for possible clues as to what breed they belonged. their description did fit that of a mottled duck but there's only one problem they are white from the bottom please help me identify these ducks

 

[Amiga]

Do you have a photo or a link?

 

[Amykins]

They could be bibbed. I'm with Amiga, could you please take a photo to show us? I like mottled ducks, they look like mallards only with REALLY big noses. Also, welcome to BYC!