(Original Forum Question : am quite into this shell collecting hobby already and as other collectors experience I begin to be more seroius on it and would want all if not most of my specimens with their individual information or data on them. I have been purchasing shells from shellshops in the philippines, auctions and sites in the internet and even exchanges ( of Phil. sp. only )from other places,,, but how can i be sure if the data labeled specially the place of origin plus the habitat where it was caught are the real or the right ones???? worst even how can I label shells which i bought from shellcraft stores ( who do not normally sell shells with complete data )with their exact place of origin...)

The only shells for which you can be certain of the collection data are those you collected yourself, and then only if you keep good field records and don't rely on memory. Receiving a shell from someone else who has personally collected it is reliable if that person keeps good records. But data on a shell purchased from a dealer cannot be verfied. For the most part, dealers do not personally collect most of the shells they sell. They purchase from wholesale suppliers, who for the most part likewise do not personally collect the shells they sell. Wholesalers typically purchase shells from various local collectors, fishermen, etc., some of whom may keep reliable records, many of whom do not. Some wholesalers try to keep separate data for each lot of shells they purchase. Others pool the shells of a given species, received from several suppliers. Some wholesalers, especially in the Philippines, make regular buying trips to various outlying islands, dealing with fishermen and local collectors, or with local suppliers who in turn purchase from local collectors. The chance that detailed collection data will remain with a specific shell through several changes of hands is, frankly, not good. That's why most dealers provide only fairly general locality data. Better to have accurate general data than inaccurate specific data. The above is not a criticism of the dealers in question. It's just the way it is, and it affects even the most honest and meticulous dealers. That having been said, there are of course some suppliers or dealers who will simply fabricate collection data because a specimen shell with data is worth more than a shell without data.
(Answer by M. Paul Monfils via the Forum)
 

I think You know the answer : if there are no data or if the data are not reliable , You just cannot know or be sure . At least if You find a cypraea englerti in a shell shop in florida You can presume it comes from somewhere on the Easter Island . Every collection has a good number of shells without or worse with wrong data . That is the real problem : shells provided with ( bona fide or MALE FIDE ) wrong data . I suspect data on some of my cernica from rare locations ( expensive )to have been manipulated , idem dito for cypraea ocellata that came from 5 " different " locations but looked suspiciously similar ( except the price who was tenfold for some of them ) .I prefer to have a nice cypraea without any data , than wrong data.
(Answer by M. PVDB via the Forum)