I think (at) isn't capitalized because otters don't have the agouti pattern of ticking in their fur, and they look more like solid rabbits which is (a), but they do sill have the agouti trim - eye circles, around the nose, jowls, inside ears, back of the neck,and the underbelly - like the agoutis do. That is why they are still part of the agouti genetics. They are in-between and that is why I like to call them "solid agoutis"