Is a Seahorse a Fish?

Do you know how seahorse gets its name? Well, despite being a fish, seahorse belongs to the genus Hippocampus. which comes from an Ancient Greek term, “hippokampos”. Hippo refers to a horse, and kampos refer to a sea monster. So that’s a quick breakdown of the name “seahorse”, but is a seahorse a fish?

In this article that’s exactly what we’re going to find out!

Is a seahorse a fish?

Seahorses are small marine fish that live in water, have a swim bladder, breathe through gills, and have a brood pouch. Although, they don’t have any snake-like tail or caudal fins. Instead, they have a snout that points down and a neck similar to that of a horse. That’s where its name comes from. There are a total of about 45 known species, and this number may increase or decrease.

Seahorse behavior

Seahorse Habitat & Size

Here is a list of seahorse habitats where they can be found.

  • Mangroves
  • Estuaries
  • Coral reefs
  • Seaweeds
  • Seagrasses

Seahorses can also be found in water that’s not too cold or too deep, and salty waters ocean water that meets with the fresh river water. Sizes of different seahorses varies from 1.5cm (smaller than a strawberry) to 35.5cm (bigger than a boot). Their heights measured from bony heads to their curly tails. Of course, this variation in height depends upon their type.

Now let’s learn a little bit about what seahorses eat.

A seahorse’s diet

Seahorses don’t have teeth or a stomach, so how do they eat? Instead of using their mouth, they suck all of their food like a vacuum using their snout for a tube. That’s why they eat only the smallest creatures that can fit into their mouth. They eat mainly baby fish, shrimps, and other small sea creatures.

They swim slowly and do not chase their prey. Instead, they do sneak-attacks to catch a meal. Because of these sneak attacks, they are also known as ambush predators.

As they do not have the stomach to store and digest their food, they have to eat regularly to survive. Every day, they eat about a tenth to a quarter of their total body weight. These all about what do seahorse eat.

Seahorse Reproduction

Seahorse reproduction is one of the rarest phenomena, especially in the animal kingdom. Instead of the female seahorse, the male seahorse becomes pregnant. The male seahorse carries eggs released by a female in their brood pouch.  Female seahorse releases up to 1500 eggs at once which male carry them for between 9 and 45 days.

He carries the eggs in his pouch until the fully developed baby seahorse emerges. Young seahorse then go off into into the water, and the male again gets ready for mating almost immediately.

That’s a summary of what happens, but the seahorse reproduction process is much more complex and divided into four steps.

  1. Courtship
  2. Fertilization
  3. Gestation
  4. Birth

Let’s learn about seahorse reproduction a little more in depth.

1. Courtship

Seahorses generally court for days before breeding. According to scientists, courtship is a process animals do to synchronize the reproductive states and their movements. Once synchronization completes, the male is ready to receive the eggs in its brood pouch, if the female is ready.

In this stage, they tend to swim together with their tails attached, change color, dance (also known as pre-dawn dance), and even grip the same seagrass strand. The female inserts her ovipositor (tube-like organ for laying eggs) into a male seahorse’s pouch and releases the eggs.

As she releases her eggs, her body becomes slim, while the male’s body swells.

2. Fertilization

While fertilization is happening, the male’s pouch opens up for about 6 seconds and egg deposition takes place. Seawater also enters the pouch along with the eggs that begin the motility, and sperm activation. This protected type of fertilization decreases the sperm competition among the seahorse males.

3. Gestation

In this stage, a seahorse male supplies the prolactin (required for milk-production in mammals). The pouch provides a controlled environment, incubator, and oxygen. The eggs then hatch inside the pouch, and salinity water prepares the life for newborns. This process lasts about 2 to 4 weeks depending upon the species.

4. Birth

A newborn seahorse is called a fry. Males release an average of 100 to 1000 for larger species. They typically gave birth to newborns at night and can be ready for mating in the morning again. Similar to other fish species, seahorses don’t nurture their newborns after birth.


Interesting facts about seahorses

  1. Seahorses don’t have a stomach or teeth.
  2. Male seahorses can deliver their babies in the morning, and be pregnant again by night.
  3. Eating food regularly is necessary to stay alive for seahorses, as food passes through their digestive system very quickly.
  4. Seahorses usually swim in pairs with their tails attached.
  5. Seahorses are eaten by penguins, big tuna fish, rays, sea turtles, and crabs.
  6. At the time of mating, the female seahorse leaves up to 1500 eggs into the male’s brood pouch.
  7. Seahorses involve in an eight-hour courtship dance. This dance includes wheeling around, changing colours, and swimming side by side by attaching their tails together.
  8. There are 47 known species of seahorses in the world.
  9. One unique seahorse fact is that seahorse male carries the unborn babies, which is unique in the animal kingdom.

What threatens seahorses as a species

Humans are the main threat to seahorses. They are used for pseudo-medicines in Korea, Japan, and China. In these areas, they are believed to treat severe diseases such as sexual dysfunctions, pain, and asthma. Some species of seahorses can even be kept as pets in the right type of tank and setup.

Seahorses also get caught by fisheries while catching fish when baiting shrimp. One of the significant reasons for seahorse dying when brought out of their seahorse habitat is that they live in areas like the coral reeves, mangroves, and seagrass beds. These areas are highly sensitive to climate change, pollution, and other human disturbances.