The dolphins were filmed gently playing with the puffer, passing it between each other for 20 to 30 minutes at a time, unlike the fish they had caught as prey which were swiftly torn apart.
Zoologist and series producer Rob Pilley said that it was the first time dolphins had been filmed behaving this way.
At one point the dolphins are seen floating just underneath the water's surface, apparently mesmerised by their own reflections.