While his preferred colony of choice was large enough to take it. My tailspot blenny constantly munched on montipora. I think a cardinal will be great as well as the gramma. Fang blennies did well in my 40 breeder. They just need their spot to sit that would be far enough away from gramma territory.
Sixlines, dottybacks are not gonna be peaceful.
Sixlines, dottybacks are not gonna be peaceful.

