Facts and Information
When it comes to reproduction for sharks, they don’t produce high volumes of offspring. However, they do produce healthy young most of the time that have a very good chance of overall survival due to the protective nature of their mothers.
Sharks tend to mature at a slow rate when you compare them to other types of fish in the water. This is a factor that has also made it very difficult to increase populations through various conservation efforts. To make it even more of a challenge, almost all species of sharks do poorly in captivity.
In the wild, it can be at least 10 years before a shark will mate. The age can depend though on the species of shark and in some cases, they may be 15 years old or more before they mate. Since sharks are fishes, they give birth to live young or eggs.
Depending on the species of shark, the process of reproduction could be sexual or asexual. With sexual reproduction there is the mating of a male and female shark that takes place. The male is able to deposit sperm into the female which will fertilize the eggs. There have been very few occurrences of such mating being observed by humans due to the aggressive nature of the males during mating.
The males may become aggressive towards each other in order to have the right to mate with females. The males will circle around the females and even bite her skin in order to get her attention. Many older females have been seen with substantial bite marks on them from the mating rituals. Experts believe the skin of the females is thicker though than males and the bites aren’t painful.
There are a few documented cases of asexual conception with females where they have had no contact with males. However, it isn’t believed this is a wide spread practice in the wild among species of sharks. Yet what it is so interesting is that this could be an evolutionary practice that allows reproduction to occur without a male present. Experts do have concerns though about this process because it can limit the genetic pool in terms of overall diversity.
There is a great deal that still isn’t fully understood regarding shark reproduction. This is due to it taking place in the depths of the water and the risk for humans that are too close when such an activity is taking place.
Some species of sharks give live birth to their young. This is referred to as viviparity and includes Hammerhead Sharks. Others deposit eggs into the water such as the Port Jackson Shark. This is called oviparity. The majority of species of sharks though are ovoviviparity where the eggs hatch inside of the mother.
The young are then born alive and they are able to completely function on their own when they are born. This process is one that allows the young to be born at a larger size, and that can help them to ultimately have a higher chance of surviving to adulthood.
The females will often migrate to sheltered areas including bays and shallow reef areas before they give birth. It is believed that this is instinctive to help increase survival as there are fewer predators to be found in such locations.
The gestation period can vary based on the species of shark. It often ranges from 18 to 24 months. However, for many of the species of sharks there isn’t enough information to know how long that period of time is. Since there isn’t information to collect for mating and it wasn’t observed there is simply no way to know how long it was from that point until the young arrive.
