An aquarium spokeswoman said visitors saw the injured shark and alerted staff that they had also seen things float from the gaping wound.
'It (the bite) was on the side and very deep, it was like an impromptu C-section and the sharks actually got born out of the side,' said one woman who saw it happen.
Savage: The shark is recovering after being attacked in its aquarium. The stitches in its side are clearly visible (below)
The mother's wound was stitched by a vet at Kelly Tarlton's Underwater World in Auckland.
'She's doing well, but we're watching her closely as it's a one-off occurrence, so we're not sure how she'll do,' a spokeswoman said.
All eight baby sharks survived.
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.
Ms Davies said the unusual delivery had probably saved the baby sharks' lives.
If the mother had given birth naturally, most likely at night, the babies would have been eaten by adult sharks and stingrays before staff could rescue them.
Thriving: The baby sharks were removed from the aquarium to protect them from other sharks
Another staff member said: 'Once they are born they are on their own and parents do not hang around at all and they have to fend for themselves.'
Last week a Great White shark was caught off the coast of Australia after being attacked by another "Jaws" which took a huge chunk out of its victim.