Wierd axolotle death

Question
well this is just something i cant do anything about but intrigues me. last year i had two axolotls, one male and one female. they had bred once before with the eggs fertilised, though the parents ended up eating the newly hatched babies. when the male released sperm again next time they bred, the female started to float. she couldnt seem to swim down without just rising to the surface. she then started to lay eggs but this time the eggs were strange, with up to eight black spots (tiny baby axolotls) in an egg. she lay lots of eggs like this and the day after finishing laying, she died (still floating). both of the parent axolotles were only about a year and a half old and the first batch of eggs the female laid were normal with only one black spot per egg.the male is still alive and doing well and i raised the babies and although most died (there is a high mortality rate)i now have seven healthy juvenile axolotls that i will sell. some of the babies in the eggs with lots of babies were mutated and died very early on. i just wondered if you could provide an explanation for the strange eggs and the death of the feamle due to laying because i asked my friends mother who has been breeding axolotls for years and she said this has never happened to her.
thanks

Answer
Hi Zoe:  Fish and some aquatic animals have something called a swim bladder that helps them sink, rise, and swim right-side-up.  When something happens to the swim bladder...its usually filled with a gas not fluid... the animal/fish cant sink or it swims up-side-down.  This sounds to me what may have happened to your axolot.  The strange eggs were probably a symptom of the issue with the swim bladder... which can also mean fungus, bacteria, or even internal parasites.... hope this helps... dave