I found a great underwater video stream of an Amazon aquarium. It captured my daughter's attention for a few minutes and I think if there was a sound feed as well it would be even better. The feed is a bit slow but there are some great fish in this display.
Here is an excerpt of what is happening in the aquarium:
Here is a glimpse into the rich and vibrant underwater life of the Amazon. When the large, serpent-like arapaimas swim past the camera, you will get a close-up look at one of the largest freshwater fish in the world. The ones you can see here range from 5 to 6 feet in length, but may reach up to 10 feet and weigh 300 pounds. Red-tailed catfish, black pacus, and other fish share this 27,000-gallon aquarium below a living tropical forest.
I've had a number of the fish seen here in my aquarium over the years. I really don't have time these days to care for my own aquarium so I am happy to watch this one from afar.
PS: You need to wait a few minutes for the feed to load. Scroll down to see it. When it appears, right click on it and make it full screen for a special treat.