Well the most common pearls people use for jewelry and stuff are oyster pearls however it is common for other bivalves to form pearls as well. A pearl is basically the result of an irritation in the soft tissue of the shellfish. Because it is irritating, the body walls it off the irritation as a natural defense, sort of how our body can form abscesses to wall off infection. So the shellfish deposits shell material around the irritation preventing it from getting worse thus forming a pearl Not all shellfish create white colored pearls either
(about the scallops) that is so cool and that makes a lot of sense y they clamp closed so tightly..and i never know that they could swim that is really fascinating:)...is it scallops that carry pearl or is it any fish that carry pearls or am i just watching too much tv lol:D??
The scallops can't breathe out of water persay because shellfish have gills just like fish inside their shells. They can survive out of water for certain periods of time by "clamming up" their shells tightly that's why bivalves exposed on the shore when the tide goes out will survive :D Scallops are also shellfish that can swim (not sure if you knew that) That's what made me so fascinated by them LOL
You could youtube them clapping to see what it was like in my photo lol I would link you to a good one but it won't not let me post it