The 11 pages listing of North, Central and South American oysters in opening pages of The Grand Central Oyster Bar & Restaurant Cookbook (Stewart, Tabori & Chang- October 2013) counts a few offerings from Mexico.
Two of them are Carlsbad del Sol (Baja, Mexico) described as Sweet and of Regular size and Meximoto (from Kumamoto family- also from Baja, Mexico) described as Cream and Sweet with a Hint of Brine and of Regular size.
I now feel the need to taste them since they are completely new to me.