Why would shells be a problem for fish and amphibian eggs?

Not only can shells contain tiny parasites, but they can also throw your water parameters out of balance. Both of which can cause fish lose.

Why would shells be a problem for fish and amphibian eggs?
I don't think shells would be a problem, but they would be a hinderance to fish and amphibian eggs.



shells are not permiable to water and therefore must contain all nutrients except air when created. That puts a great deal of burden on the mother to provide those nutrients.
Reply:It takes energy and nutrients to make an egg shell.

A prime function is to lock in moisture, and that isn't needed when your eggs are in water.
Reply:there's a few answers for this, to side with the answer that you don't need a shell when your eggs are in a consistantly wet place, the fish and amphibians also (mostly) fertilize the eggs once they're outside the mother's body so if they had a shell, the male's genetic material wouldn't be added and even if by some fluke they did live, this wouldn't create genetic variation.



also, fish and amphibians would need fewer nutrients to create the shell itself. in addition, most amphibians and fish use an adaptation in which they lay LOTS of eggs, taking the chance that a few of those eggs will survive rather than spending more time raising individual offspring, so the demand would be great for nutrients, seeing as how the number of eggs is so large