It will last until it is eaten. It has no expiration date. Early frontiersman used beef jerky on the trail when fresh meat was unavailable. They learned from the local Indians how to smoke fish.
This will depend upon the smoking process that has been used. Some smoked fish - like lox - must be kept refrigerated and will have a short shelf life, since there's still plenty of water activity. Meat that has been dried - like jerky - will last longer. Follow the manufacturer's guidelines. Also see Related Links.
Chat with our AI personalities
You should not hold the smoke in. It really doesn't make you very much higher, and apparently it is much, much worse for your lungs.
I will add to the answer above by saying that you should consider not smoking this stuff at all. It is a waste of time and is extremely addictive to some people.
[Additional answer deleted because the poster was obviously highly anti-MJ and went on a rant]
Only for as long as you can hold it. Don't listen to people that say you have to hold it in for long, because that's BS and you absorb the thc in seconds.