The queen conch (pronounced “konk”), or pink conch, is becoming endangered.  The strombus gigas can grow to be quite large and has a pearly pink inside.
The shells I own (in the photo below) were purchased many years ago at a shell shop…can’t even remember where, but probably on Sanibel Island or Fort Meyers in Florida.
The Queen conch is an edible sea snail and a prized delicacy in parts of Florida and the Carribbean has been overly fished as a food source. This mollusk is found in the tropics from Bermuda to Brazil and fortunately some areas now have strict guidelines against over fishing.  (See the links below for more info).

The Southern Regional Aquaculture Center (SRAC) has photos of baby conchs and the life cycle and info on what can be done to help relieve the problem.    And read more at this site.