Pauly D First Baby Pic -- My Kid's Already Fist Pumping!

Meet the new princess of Jersey ... Pauly D's 5-month-old baby girl, Amabella.

We broke the story ... Pauly D hooked up with a chick he met in Vegas in the Fall, 2012 ... and this is what happened.

Pauly has already taken a DNA test which pretty much conclusively proved he's the daddy ... so Maury, stand down.

As for the name ... we're told Amabella means lovable in French.

She was born on May 15 and, based on the pic obtained by TMZ, already needs a haircut ... just like her daddy.