This could be ( and I stress COULD be) part of the problems with domesticated Angels today. Repetative inbreeding is known to cause dwarfism which in turn is past along the more generations of inbreeding that goes on. This is from breeders not bringing in "new blood" every few generations to keep the master genetic code strong. Whether intential or unintentional, not adding outside genetics to a line will have disasterous results at some point. (You and I may be witnessing this point
) It's why there are so many fish on the market with short or bent fins. Breeders not caring about the genetic lines kept breeding deformed fish and putting them in the marketplace. Unsuspecting hobbyists come and buy the fish and breed them to another fish without knowing that they are breeding to a sibling thus creating this genetic mess. In my recent case, I was told by the store owners that they each got their Angels from a local breeder. Since I bought 2 fish (of the same color) from the stores, I have to assume that these fish are siblings or, at the very least, from the same parents. These are not good fish to breed together. Considering that the only fish of mine that right now is big enough ( in my eyes) to breed is my straight Koi, my Silver spawning is already a disappointment. I bought her when she was about a 1/2 dollar size so that should have been too small to breed for a few months. It's only been a few weeks since I've been back home with her. ( You see where I'm going with this?
)
What you are seeing with wigglers not free swimming 5 days after hatching may be the results of these poor genetics in your fish. Not knowing the exact age of your fish doesn't help eliminate this as a possibility. Being young should not be the cause of this. ( e.g.: Is the pregnancy time of a 13 year old human different in length from a 25 year old? ) I'd also check the accuracy of your thermometer. At 80 degrees, fry usually become free swimming in about 3 days. If yours is accurate and this is the results of your spawn, I'd consider not breeding this pair again and try to find a much larger proven breeding male to get the size genetics back into the line. (That's my plan if mine doesn't start growing more.)
A long winded answer I know
but I think the crux of the matter in your case.