(W.A. Swainson 1831) - Common name Pink Mouthed Murex - Size range 45mm-153mm - Range: Sea of Cortez, West Mexico
 
Nice color, larger than average Erythrostomus Murex. Most of these that I see collected are at most 110mm.  Collected live by local panga boat hooka divers somewhere between Puerto Penasco and Desemboque, Mexico. 7-10 meters depth.  Tides range 7 meters / 24 feet in Puerto Penasco, so the divers usually go out during  low tides to collect murex and other species for meat.
 
The snail was removed by the local Mexican fishermen for the meat, for once I am shocked, as there is little to no damage by them. Due to the very warm waters of the Sea of Cortez, these murex come completely covered in heavy build up.  Shells this size and age are deteriorated naturally.  I've never seen any better.  Nothing can be done about the deterioration.  I clean all my shells the same.  So any defects and color variations are natural as seen in the photos.