Yes.
This is a blog entry from their site
http://www.aquariumofpacific.org/blogs/c ... It explains about the sharks laying eggs in the big shark display tank, and how they collect them and move them to the sump filters to hatch. That's 5 to 20 eggs every day.
I'm also sure that in those big display tanks many of the smaller fish breed naturally, just as they would out on the reef. And some freshwater fish, well it's almost impossible to stop them breeding if they are kept in good conditions.
Ian
