when can an infant be allowed to eat fish?

Answer 1

A general rule of thumb for fish is waiting until the infant is 12 months, or 1 year...

But, pureed fish as early as 7-8 months would not cause any problems for for the infant...(unless the baby is allergic to fish!).

Here is a great and reliable source of info on feeding infants:
http://www.med.umich.edu/1libr/pa/pa_menu7411_pa.htm