Ragged-tooth sharks (Carcharias taurus), also known as grey nurse sharks in Australia and as sand tiger sharks in the USA, occur in temperate to tropical coastal waters of the Atlantic, Indian and western Pacific oceans. In South Africa they are common along the eastern and southern coasts, occurring as far west as False Bay.
Like all sharks, ragged-tooth sharks have a cartilaginous skeleton. They grow to about 3,2m in length and live for about 30 years. They reach sexual maturity after 5 years, and at approximately 2.2m in length.
Sharks’ teeth are arranged in rows which continually move slowly forward, like conveyor belts. This ensures a constant supply of sharp, new teeth and results in sharks losing and replacing thousands of teeth in a lifetime.
Ragged-tooth sharks are threatened around the world because they are slow to reach sexual maturity, they give birth to few young and, because of their inshore habits, they are highly vulnerable to over-fishing.
The status of the South African ragged-tooth shark population was considered to be “near threatened” by an International Union for Conservation of Nature working group in 2003. However, the actual size of the population is unknown and is currently under investigation. By tagging and releasing our sharks, we are able to contribute to this important research work.