Thanks to someone on our homeschool forum, we watched a live webcast about Winter the Dolphin. She is a dolphin who lost her tail at three months old. A prosthetic company heard the news and offered their services. They talked about the process of training her to take the tail and how they fit her in 7 tails up to the one she is wearing now. She just turned 4 years old. She doesn't use her tail properly but can at least swim. Hopefully by watching the other dolphins she'll learn.
This is a picture of Austyn holding a lego dolphin he made. He made it before the webcast but during it he left the room for a second, came back, and said "Look what I did". He had removed the tail.