Swell Protection : The Puffer fish, swollen almost to bursting point, when danger has passed the fish returns quickly to its normal size. The puffer or globe fish (belonging to an order related to the perches) has many strange attributes and undoubtedly the most astonishing of these lies in its ability to swell itself out to an extraordinary size as a protective measure. On being attacked or anticipating danger the puffer swallows either water or air until the body is blown out like a balloon, thus becoming too large for the jaws of the bigger fish whose natural prey it is. September 01, 1953. (Photo by Paul Popper).