I got four baby jags 15 days ago. They are about 2 to 3 cm. The problem is while two of them swims normally like a healthy fish, the other two smaller ones tend to stay at the bottom most of the time. They seem to have a hard time to reach to surface and keep at any height. They seem to grow slower or don't grow at all. I got them from a near city and they were in a plastic bag for 3 hours in the bus. May this be the reason? Can they recover?