"Female sand tiger shark produces 400 to 500 embryos at a time. While still in the womb, these embryo sharks grow razor-sharp teeth, the embryonic sharks start to eat other embryos. Within a few months, three to four dominant sharks engage in a life-or-death struggle until only one survives. By the time it is born, the sole-surviving shark pup has become an experienced predator. Amazing film taken inside the womb recently appeared on UK television clearly demonstrating this behaviour."
Thanks for the info. I never knew this and found it to be very interesting.