Help! Newt baby is more vertical...

Newty, the FBN larva first noticed on 3/12, appeared to be belly-up a minute ago. His belly only recently began looking pigmented like his parents and the boys and were excited. I went to get him and he swam away. I isolated him. He can be horizontal in the water but his head has a tendency to be above his tail and I'm fearing the worst. I have four about his age, ten that are 3-4 weeks younger and about 10 new hatchlings. The water is OK - just ran a quick ammonia and nitrite test. He's a good size, almost an inch maybe. I think it's too young to morph so I'm very worried. Should I call my exotic vet? I'm worried my diet for him is inadequate. I've dragged my feet on getting the blackworms so it's been live Daphnia (diminishing pool left), frozen Daphnia-like mix, and frozen baby brine shrimp. I don't want to lose the whole gang - feeling guilty over wondering an hour ago what we'll do w/ all these newts...

Thanks,
Dana