No. This is not generally done. The containers for delivery food will vary depending on the restaurant and type of food, but they are generally boxes and cartons that are not regularly sealed, let alone with tamper-evident seals (there's sometimes a piece of ordinary tape or a staple to keep a box or bag closed). I can't guarantee that nobody does what you ...
It's called 'Shirasu'. It's the juvenile offspring of anchovies, herrings or sardines.
In other parts of the world it's called 'whitebait' or 'gianchetti', or...other names. The exact species varies from place to place too.