Admit it: you’re probably a lot like nearly everyone else on this big, spinning blue planet of ours – you think about sex with quite a bit of frequency. According to studies, men under 60 think about sex at least once a day, while women think about it most frequently during the most fertile portions of their cycle. The question isn’t about how often you think about sex though – it’s about how and when sharks think about it. And, when they get together, what happens? These large predators have astonishingly complicated sex lives. Let’s take a closer look.
How Sharks Mate
Like other sophisticated members of the animal kingdom, sharks are equipped with external reproductive organs. A female shark has a cloaca, while a male shark has a pair of claspers. While sharks are fish, they differ from bony fish in that they do not reproduce via spawning, leaving things to chance. Instead, they copulate in the same way that mammals do, which leads ultimately to internal fertilization.
During mating, the male’s claspers enter the female’s cloaca; it’s then that the origin of the organ’s name becomes evident. The claspers actually open up inside the female, ensuring that the two sharks remain connected until the male has had a chance to deposit his sperm.
As an extra means of ensuring the connection between male and female remains secure, the male shark bites the female throughout the mating ritual. This does not occur in all shark species; however in species where it is prevalent, female sharks are equipped with thicker skin in order to more easily withstand the force of their partners’ lusty bites.
Once mating has concluded, the two sharks go their separate ways. In some species, female sharks lay eggs; oviparous sharks leave egg cases behind. These are sometimes called devil’s purses or mermaid’s purses. They are typically deposited onto the sea floor in pairs, and young sharks hatch from them as long as about nine months later. If you find sharks’ egg cases while diving, try shining your light behind one and peeking through the other side – you may be lucky enough to get a good look at the young shark developing inside the egg case. Some rays and skates lay similar eggs and in many cases, it’s fairly easy to identify the species inside; just remember never to disturb the egg cases.
Other shark species are viviparous, meaning they give birth to live young. Some sharks have litters of several pups, while others have just one or two at a time. Shark pregnancy can last as little as four to five months, or as long as about two years. Once the shark pups are born, they are pretty much on their own – but don’t worry; they’re equipped with sharp teeth and all the instincts needed for survival.
Finally, many shark species are Ovoviviparous, meaning that they produce eggs that contain young sharks, but those eggs develop inside the female rather than out in the open ocean environment. The eggs hatch inside the female then the shark pups continue to develop inside their mothers. These sharks are not connected to their mothers via umbilical cords as viviparous sharks are – instead, they get their nutrition from the yolk sac or from secretions from the uterus. In some cases, larger shark pups consume smaller ones in vitro – preying on their own siblings before they’re even born.
From the very beginning of the mating ritual to the birth or hatching of young sharks, shark reproduction is fascinating. It’s an exquisite wonder of the natural world. Next time you encounter sharks while diving, take a good look – you’ll be able to tell whether you’re viewing males or females, and if you’re very lucky, you may even get the chance to witness a little shark romance for yourself.
Comments
Learned alot reading this article. Thanks!
Loaded with helpful info. A good read.