Re: How do I show growth in a fish other than observation?

I'm not sure what to expect from your experiment, so choosing your assay is 
a bit tricky.  I will list the kinds of assays that might be informative:

1. Effect on viability:  do fish die more often when fed folic acid?
2. Effect on growth:  is the rate of growth affected by folic acid?
	A. weight:  measure weight of fish over the time course of your 			
experiment using a sensitive scale. 
	B. size:  use a ruler to measure them as they grow
3. Effect on regeneration:  is fin regeneration affected by feeding folic 
acid?
	- Fish regenerate their fins when they are damaged.  Use scissors to 
amputate fins and then go back to the fish at later stages and see if 
regeneration is altered (by simple observation of regenerating fins or 
measuring the extent of regeneration with a ruler).

Remember to include your negative controls too!