I found this hard to believe, but here's the video.
Click to view
This happened at The Wild Animal Sanctuary in Keenesburg, Colorado. From their website, I learned that some pride's favorite treat is red-meat, while other's are poultry (chicken legs). Fish must be added to provide variety to their diet.
There is something else very un-lion-like about this video. Notice how once the lions pick up the fish, they (wishywashily, symbolically, ritualistically) shake it--this is not something I've ever seen lions ever do with their food--usually they just chomp right in. I'm (strongly) guessing the lions learned this behavior from the bears that are kept in ranges beside them--this is bear behavior that the lions adopted when confronted this new, strange thing.