Man I guess these things are fragile at a juvie state. Mine for no reason started breathing really rapidly yesterday morning and by tonite she was toast. Ph was stabile, no ammonia, nitrites. Truly puzzled, and she was looking so vivid.
Belly Crawlers come from heavily oxygenated waters, so if your tank got warmer and you didn't have enough aeration going its very possible she affixiated.... Pikes are relatively sensative to water conditions when they are smaller, especially below 4"...but your baby was quite a bit larger than that.