Biology

How do Sharks Mate?

Do sharks mate? How do they reproduce? I am pretty much sure, you have never asked these questions to anyone but these questions are very interesting to answer. All sharks are vertebrates and are known as one of the most regional aquatic animals. Like all other fishes, they do not breed by releasing gametes in the water which swim towards eggs to produce larvae. Like mammals, sharks undergo internal fertilisation where both male and female sharks mate and further reproduction takes place inside the females’ body. You might be curious about how sharks manage to achieve this complex physical operation in an aquatic atmosphere. Let’s study in detail the mating behaviour of sharks to reduce your curiosity level.

Do sharks require a particular mating habitat?

About 400 species have been studied that are living in aquatic and marine ecosystems, each species have different and unique styles of mating and reproduction. Some shark species had to travel long distances to find their mate and reproduce by laying eggs or giving birth to their young ones. Although sharks have different styles of mating, but they all experience internal fertilization and follows asexual mod of reproduction.

Most of the sharks perform their mating activities in the deep and murky ocean water, so it is very difficult to observe their habitat but a lucky diver will catch a glimpse of sharks’ courtship and take a snap so that some anxious researcher (like you) will analyse it. Sharks love to swim spend their life in the deep and shallow water and prefers to lay eggs on the ocean grounds as they have swarm and shallow water with number of nutritive food available in these areas for them as well as for their newly born pups, the gestation period of sharks is long lasting may be up to of 3 to 4 years.

How do female sharks attract their ideal mate?

To find their mate during the breeding season, some sharks had to travel long distances, but it’s not the same for all sharks, they adapt different techniques to attract their mate. The female sharks release some chemicals named as “pheromones” in the ocean water which fascinate the male sharks and rouse their interest. As you know, sharks live in different localities under the water so these chemicals help female sharks to locate and find their mates. Sharks have well-developed organs called lateral lines which detect the vibrations and electric fields produced in the water when they are ready to mate.

Do female sharks have mating marks?

What? Male shark bites? Why? Yeah, a male shark bites female sharks with their sharp teeth only to get the attention of female sharks. Male sharks usually bite on the back, pectoral fins and flank on the female shark’s body, sometimes leaving deadly wounds and scars, but these wounds do not have any serious impact on the health of female sharks because the skin of female sharks is very thick and rough.

Do male sharks get rejected?

It is funny but yes, that’s true, male sharks also get rejected by female sharks. Male sharks once in a year are always ready for courtship; to be in the spotlight they bite the fins of female sharks, they start widening up the pelvic fins which shows that they are interested but if they don’t like male sharks, they avoid, block or refuse them. Oho! Rejected! It is also very interesting to know that during the breeding season, single male sharks can mate with a number of females, and in the same way, females can also mate with many males thus have high reproductive and fertilisation possibilities.

Fertilisation – The beginning of courtship behaviour

Sharks do not mate for their survival, in fact the mating happens only once in 2 to 3 years. All sharks practise internal fertilisation during the mating activity, copulation starts when they find their ideal mates. The male reproductive organ is named as clasper and the females have cloaca.

The mating rituals include the biting phase, in which both male and female sharks bite each other showing their interest. After that, male insert claspers into the cloaca and inject the sperm into the female body where further fertilisation occurs. The spermatic fluid moves to the oviduct to fertilise the eggs. In some sharks fertilisation may occur at once but in some species it requires 3 to 4 years to proceed the process. The procedure is not easy for both the species as they have wounds on their skin, sharks do not use all the sperm at once, some species like bamboo sharks store the sperms for future use.

What happens after courtship?

After eggs are fertilised, the development of the embryo takes place. As the development proceeds, the embryo receives nourishment either from the yolk only called as lecitho-trophic or both from the yolk and mother termed as matro-trophic.

In how many ways sharks can reproduce?

Some sharks reproduce by laying eggs while others give birth to their young ones. Generally there are 4 types of reproduction that were observed in different species of sharks.

1 : Viviparous reproduction

This type of reproduction occurs when the eggs hatch in the uterus of the female shark’s body, the umbilical cord provides nourishment to the developing embryo attached to the mother just like in mammals. This reproductive form is mostly observed in reef sharks, bull shark, salon shark, blue tip shark and lemon shark.

2 : Oviparous reproduction

This form includes the deposition of fertilised eggs in the ocean mud and hatched outside the body of female sharks, the eggs produced by this method are called mermaid purses. The water in the surrounding provides oxygen to the developing embryo by penetrating into the egg shell. The egg shells bear tendril and horn which helps them to stay wedged to the surface and also provide protection from predators. The reproductive behaviour is mostly observed in epaulette shark, swell shark, zebra shark, cat shark and many others.

3 : Ovoviviparous reproduction

This type of reproduction includes sharks which have the ability to lay eggs as well as give birth to their young pups by hatching eggs inside the female shark’s body. This mode of reproduction is quite advantageous because they are being protected from predators and safely complete the developing time inside the mother’s body. Tiger shark, nurse shark, gummy shark, thresher shark, exhibits such reproductive patterns.

4 : Asexual reproduction

Asexual reproduction means that a female shark reproduces without any mating behavior; this is a periodic form of breeding which limits the genetic diversity to the mother only and may results in disease and mutation development in sharks. Abruptly 2 cases are reported, hammerhead shark and short-fin mako undergo this form of reproduction.

Final words

The courtship behaviour of sharks is widely diverse, shark species exhibit different mating mechanisms, followed by internal fertilisation and development and producing large numbers of offspring. Hope this article provides you enough knowledge so that you can learn and easily understand how sharks mate and evidently makes a difference between different reproductive methods which they adapt

About the author

Ameer Hamza