Hammerhead shark
Hammerhead Sharks are viviparous, meaning they  produce   birth.    Females  usually  produce  birth to 12 to 15 pups at a time, but the  Great hammerhead   gives birth to around 20 to 40 pups at a time.   Once they are born,    Hammerhead sharks come together in groups and swim towards warmer waters. They stay together in groups until they are older and big enough to live on their own. Hammerhead sharks   live for around 20 to 30 years.     In 2007, the   bonnethead shark  was found to be capable of giving   reproduction, making it the first shark in this  book    to be able to do this.