In the animal kingdom, it is very rare for males to be responsible for carrying and birthing their young. However, there are three species within the Syngnathidae family that leave this up to the males!
In this family, Seahorses are the most commonly known fish where the male carries the young. Seadragons and Pipefish are their relatives that also birth the young.
This article will explore these animals in more detail, looking at the fascinating way that they share the responsibility of child bearing between males and females.
Anatomy Of Male Fish That Give Birth
This group of fish are fascinating. They have the ability to share the responsibility of child-bearing. Initially, the female will lay her eggs. When this happens, she will transfer her eggs to the male.
In seahorses, the male will have a pouch that is specialized to store the eggs. In pipefish and sea dragons, the eggs are attached to their tails to keep them safe.
After this, the male then fertilizes the egg. The male will carry the eggs for the entire duration of the period of incubation. The males are responsible for ensuring that the eggs have everything they need in terms of nutrients and immunity.
These animals have long snouts and rigid bodies. They don’t have a pelvic fin, instead relying on their dorsal fins to move them around. This makes them very slow fish.
Seahorses, pipefish and sea dragons are found in tropical seas and oceans across the world.
Seahorses are one of the few animals where males are responsible for carrying the young. Seahorses are commonly depicted on TV and in films, specifically shown in Disney films such as The Little Mermaid.
Of all of the males that give birth to their young, the way in which the seahorses do this is the most advanced.
Male seahorses have a pouch on their tails that is designed to carry their young. The female lays the eggs and can transfer up to 1,500 eggs to the male.
The male will then fertilize these eggs and the fertilized eggs will then attach themselves to the inside of the male’s pouch.
While they are in the pouch, these eggs are protected and the male provides the eggs with everything that they need to develop. The gestation period will last anywhere between 9 and 45 days, and the babies will then begin to hatch.
When the eggs have hatched, the male will push the young out of their pouch. This is done using muscular contractions.
Survival rate for these babies is very low, with less than 1 percent of these hatchlings surviving. Seahorses give birth to very large clutches for this reason, and the male will reproduce again just days later.
Sea dragons are very closely related to seahorses. They are uncommon fish, only found in the waters surrounding Australia which are very warm.
There are three species of sea dragon, and the leafy sea dragon is the most well known. This fish has fins that look like leaves in order to help them to blend in with their surroundings.
Male sea dragons are responsible for carrying their young. They do not have a pouch in the same way that a seahorse does, instead carrying their offspring on their tail.
On their tail, there is a brood patch which provides everything that the offspring will need during their incubation period.
The female will deposit up to 250 eggs into this patch, and the male will then fertilize these eggs. The males will then carry the young for up to three months, depending on the specific species.
After the eggs hatch, they will often feed on the leftover embryos which are rich in nutrients. When these run out, they will have to find their own food.
Another fish in this family where the males give birth are pipefish. These fish are pipe-shaped and long which is where they get their name.
They have many similarities to the seahorse as they are from the same family. These animals look like stretched seahorses.
Pipefish are very small, only growing to be around 14 inches long.
Some species of pipefish have a pouch, whereas other species simply attach the eggs to their tail. When the female lays her eggs, she will transfer these eggs to the male during mating. These eggs will be deposited in the pouch or tail.
Mating between pipefish is a very interesting thing to watch. They will wiggle and shake when they are mating, and when the eggs are deposited, they will float upwards together.
The male is then required to care for the offspring. This requires a lot of energy from the male and often takes a lot of the nutrients that the male needs for himself.
Because it can be difficult for the male, they often cannibalize their offspring in order to give themselves enough nutrients to remain strong.
Eating their young is a fairly common occurrence in the fish world, and it is known as filial cannibalism.
Are The Young Independent From Birth?
While the males in the Syngnathidae family take care of their young during their incubation period, feeding them with nutrients and boosting their immunity for months at a time, these offspring are independent of the moment that they are born.
These animals are very vulnerable as they are very small when they are born. Less than 1 percent of seahorse offspring actually survive to adulthood.
When the baby seahorses are born, they are completely self-sufficient. It is up to them to escape their prey and survive.
If the babies do not leave, then the parents will actually eat their own offspring so it is important for the seahorses to go off on their own from the beginning.
Are Seahorses Endangered?
There is no doubt that male seahorses are trying their best to ensure that their offspring survive and thrive. However, after the fish are born, there is no parental support given to them.
These fish are tiny and very vulnerable, meaning that a lot of seahorses are lost after birth.
However, lots of fish fertilize their eggs and there is no protection during the incubation period. In this way, seahorses do have a fairly high survival rate in comparison to other fish.
There are a lot of threats that the seahorse population face, though. Lots of these threats are caused by humans. There is a common occurrence of illegal trade happening where dried seahorses are sold for medicinal purposes or as souvenirs.
Seahorses are also often caught in the nets of shrimp fisheries and they are often caught to be sold in aquariums.
Facts About Seahorses And Their Relatives
- Seahorses don’t have a stomach! They have to eat between 30 and 50 times a day because food passes through them very rapidly
- Seahorses have a crown on their heads. This is called a coronet and it is distinct for each seahorse, similarly to a fingerprint
- Male seahorses can give birth to up to 2000 babies at one time
Why Do The Males Carry The Young In These Animals?
The exact reason as to why the males carry the young in these animals is not completely clear, however there are lots of theories as to why.
One of the reasons is that seahorse babies are very vulnerable and they often don’t survive after they are born as they are eaten by prey.
If the male gives birth to the baby, during the time that the male is pregnant, the female is able to create more eggs to be fertilized. This means that more babies are able to be born, meaning more will survive.
This implies that the males carry the young in order to sustain the population of these animals.
Is It Painful For Seahorses To Give Birth?
It seems to take a large toll on the male seahorse’s body to give birth. He uses a lot of his own nutrients while he is taking care of the eggs.
He also uses a lot of oxygen at this time. During the incubation period, the male seahorse is not able to do very much at all, and this can last up to 45 days. This is because he is using all of his energy providing for the eggs.
When giving birth, he pushes the babies out with muscular contractions. These are painful in the same way that they are for mammals.
After he gives birth, the male seahorse is left to recover. This takes several days, and the seahorse is unable to eat during this time.
There are only 3 fish where the male gives birth to the offspring. These are all relatives from the same family. The seahorse, pipefish and sea dragon all reproduce in this way.
There are no other known animal species in the animal kingdom in which the male is responsible for birthing the young making this very unique!