I do agree you'd be better off starting with a newly hatched shark that you the store can verify is already feeding than starting with an egg. It would help to see it feed in the store if you don't know how reliable the store is. A lot of people will tell you a fish is eating even if it's not just to make a sale.
But if you do get a shark egg or already have one, check to see how large the shark is inside by holding it up to the light. The smaller the embryo the more risky it is to reach hatching. If the egg is full you have a very good chance of hatching. At this stage they aren't very delicate. The only problem is you have about a 50/50 shot to get it to feed. But if they do they well do great under most situations and should feed very well.
Try encouraging them with garlic extract. Feed meaty foods like chopped clam, squid, octopus, shrimp, fish, scallops, and most anything else in the sea food section. There not to pick and if feeding take to most meaty foods readily.
You tank will diffennty be suitable for a year. The less you feed them the slower they will grow if you are concerned but you should put there health first and never under feed. I'd say every two to three days would be find and you can feel out how much to give them because they are very eager happy eaters when they do eat.
It's one of my favorites but the only downside I see is that it's nocturnal and doesn't swim much during the day. But they do still spend fair amount time in the open and not hiding during the day.
