I heard they were deeper water fish and when they are collected they don't bother to deco the fish. As a result the fish eventually withers away becuase it's air bladder has been ruptured.
Of course this is just my theory, guys at roozen once told me this and I did some reserch on it. Came across a couple of collectors in Hawaii and south pacific that verified the deeper the fish is caught the less likely it is to stay alive.
But just cause i read it on the internet doesn't make it true.
B