Visitors to Kelly Tarlton's Underwater World were stunned to see one shark give another shark an impromptu caesarean section.
Staff were initially dubious when visitors came running to tell them there were baby sharks spilling from a wound in a female school shark's stomach - courtesy of a large bite by another shark.
But they found a female with a large gaping stomach wound and four babies swimming in the tank.
Kelly Tarlton's aquarist Fiona Davies said it was common for sharks to take chunks out of each other, even in the wild, but she had never heard of anything like this.
"It had to bite a certain part to let them out and do it without killing them [the babies] or her [the mother]."
Ms Davies said the unusual delivery had probably saved the baby sharks' lives.
Staff did not know the mother was pregnant and, had she given birth naturally, most likely at night, the babies would have been eaten by adult sharks and stingrays before staff could rescue them.
The young sharks have been taken to a "nursery" tank with some baby eagle rays, where visitors can see them before they are released into the wild.