Muricanthus ambiguus Reeve, 1845 165mm Puerto Escondido, Baja Sur On a huge boulder at 50'

These two shells are the same length but vary greatly in width and bulk. The nigritus weighs 10.8 oz. and the ambiguus 12.9 oz. This is almost a 20% difference between the two. I think it is obvious why many consider them separate species

Muricanthus ambiguus Reeve, 1845 186mm Isla Danzante, Baja Sur On a huge boulder at 60-80' W.R. size

Muricanthus ambiguus Reeve, 1845 126mm El Golfo de Santa Clara, Sonora, Mexico On sand eating a Chione gnidia at extreme lowtide

Muricanthus nigritus Philippi, 1845 127mm Guaymas, Sonora, Mexico On rocks at 15' - Almost pure white, just a hint of color