I saw this ad for “Marine Land” with some beluga whales, and I noticed something, the appeared to be able to turn their heads independently of their bodies, unlike fish that kind of have to completely turn around to see behind them. Was I just seeing things?
"Beluga whales have a flexible neck due to cervical vertebrae (backbone) that are not fused, as in other cetaceans. This allows them to move their head up, down, and to the side. "
http://nmml.afsc.noaa.gov/education/cetaceans/beluga1.htm
That’s actually a bit misleading because there are lots of cetaceans that can move there necks to some degree. The beluga is near the upper range, but the river dolphins generally have even more head mobility. The krill feeders generally have the least mobility and the greatest fusion of the neck vertebrae.