I wouldn't call it spoiled, but perhaps freezer burnt. My new hobby freezer in the basement is a frosty kind, so it will not induce freezer burn quite so readily.
This evening they are looking very well, but now I'm worried that I won't have enough rotifers for them. My rots started to crash after being quite abundant for the month that I did not need them. I caught it just in time to preserve a few live ones, and then three days later, too much success with the clownfish! Hopefully I can bide some time with frozen ones I stored away when I was having such an excess. The larvae seemed to be striking at some frozen rots I added this evening.