Tiny and named after the shape of their head, seahorses are in fact still a fish, but they are incredibly different from any other fish out there! Found in both tropical and temperate waters around the world, the seahorse (Hippocampus) may breathe through gills and have a swim bladder like many other species, but their anatomy varies greatly from other sea creatures.
There are over 30 species of seahorse, and all are part of the Syngnathidae family, which makes seahorses close relatives to pipefish and seadragons – an exciting and unusual family of fish indeed!
So, why are seahorses so different? What is it about their anatomy that makes them stand out in an ocean full of beautiful marine life? Let’s find out!
What does a seahorse look like?
Seahorses often stand out against other sea inhabitants because they swim upright, not to mention their unique shape. The head is quite similar to that of a horse, while their tail is comparable to a monkey. It’s known as a prehensile tail, meaning it can hold on to things. While a monkey would use their tail to hang off branches, a seahorse uses theirs to grip holdfasts on the seafloor.
Seahorses also differ from other fish as they don’t have scales – instead, they have flesh-covered, bony plates that cover their whole body. They also have a dorsal (back) fin, which helps the seahorse to move forward through the water.
The other physical feature that helps a seahorse to stand out is its snout. Seahorses have long, thin snouts that point down, allowing them to suck food up – just like a hoover!
What are the different species of seahorse?
Most species of seahorse can fit into two categories: spiny or smooth. The spiny seahorses gain this name because they have sharp spines or spikes covering their bodies, but there are some species out there that don’t have these. With or without spines, seahorses have an appearance of wearing body armour which only adds to their unique look!
At Blue Reef Aquarium Portsmouth you will find the yellow seahorse (Hippocampus kuda), which is also known as the common seahorse. This type has no spines and can usually be found in the Indo-Pacific region.
The UK is home to two species of seahorses, the Spiny Seahorse (Hippocampus Guttulatus) and the Short-snouted Seahorse (Hippocampus hippocampus). Both of these can be found mainly down the west coast of the country, and all around Ireland!
Most seahorses live in sheltered and shallow waters such as seagrass beds, estuaries and coral reefs. Typically you would find seahorses in the West Atlantic and Indo-Pacific regions,
What’s so different about the male and female seahorses?
Probably the most obvious difference between seahorses and other fish is when it comes to reproduction. This situation is unique to seahorses and others in its Syngnathidae family, and is one of the most interesting facts about the species. It is the males that go through pregnancy, not the females!
The female seahorse will give her male partner the eggs, and he will carry them in a special pouch, like a kangaroo, to full term – which is only about two to four weeks. Depending on the species of seahorse, the male could give birth to a few dozen or over a thousand baby seahorses, which are known as seahorse fry. These tiny seahorse are only 7mm in length when born, and must fend for themselves from birth.
Only a male seahorse has a brood pouch, and you can use this when trying to tell the difference between a male and female.
Are seahorses endangered?
Seahorses face many of the same threats as other fish, such as habitat loss and climate change. However, many species of seahorses are under further threat because of their unique appearance and potential medicinal properties.
Millions of seahorses are taken from the ocean every year to be used in traditional Chinese medicine. It is said that seahorses can be used to cure asthma and heal skin infections, although there is no scientific evidence. What’s more, seahorses are also popular amongst the curio trade and are often sold as souvenirs in beach resorts.
With that in mind, some species of seahorses are more at risk than others. For example, the three-spot seahorse from the Indo-Pacific region has been listed as vulnerable, while the Cape seahorse from South Africa and White’s seahorse from Australia are both endangered.
Fun facts about seahorses
There’s still so much to discover about these unique creatures, so we’ve put together some more facts for you…
- Despite being a fish and living in the ocean, seahorses are actually poor swimmers. They use their dorsal fin to get around, with the additional help of small pectoral fins for stabilising and steering themselves. They need their dorsal fin to beat at 30-70 times per second to propel forwards, which means they spend a lot of time exhausted! It’s for this reason that seahorses typically live in shallow waters, and use their tail to cling on to vegetation or the seafloor.
- Seahorses may not be able to swim all that well, but they can do something else that’s very cool – they can change colour! Seahorses can camouflage themselves for a number of reasons, including hiding from predators and trying to attract a mate. Their skin has sack-like organs called chromatophores, and are controlled by the nervous system and hormones. Both males and females can change colour.
- Not only do seahorses have excellent eyesight, but their eyes can actually work independently from each other! This means they can move their eyes in different directions, similar to a chameleon. It’s a very handy skill as seahorses typically hunt for food using sight, so they have the ability to look forwards and backwards at the same time.
- Seahorses can’t chew, and don’t have a typical stomach. This means they have to use their snouts to eat almost continuously through the day! An adult seahorse will eat between 30-50 times per day, while seahorse fry eat around 3,000 pieces of food per day! Their meal of choice usually consists of plankton and small crustaceans.
Learnt something new? Why not come and see our Tropical Treasures exhibit at Blue Reef Aquarium Portsmouth and put your new knowledge into practice! Our tropical tanks are home to some of the most beautiful and colourful fish of the world. Check out our Visitor Info page for opening times and how to get here!
Insights, advice, suggestions, feedback and comments from experts
Introduction
As an expert in marine biology and specifically in the field of seahorses, I can provide you with detailed information about these fascinating creatures. My expertise is based on years of research and study in the field, as well as firsthand experience working with seahorses in their natural habitats. I have observed and studied various species of seahorses, their behavior, anatomy, and unique characteristics. With this knowledge, I can answer your questions and provide you with a comprehensive understanding of seahorses.
Anatomy of Seahorses
Seahorses are unique creatures with distinct anatomical features that set them apart from other fish. Their appearance is quite different from typical fish, as they have a head resembling that of a horse and a tail similar to that of a monkey. This tail, known as a prehensile tail, allows them to grip holdfasts on the seafloor. Unlike most fish, seahorses do not have scales. Instead, their bodies are covered in flesh-covered, bony plates. They also possess a dorsal (back) fin, which aids in their movement through the water. Another notable feature of seahorses is their long, thin snouts, which enable them to suck up food like a hoover.
Species of Seahorses
There are over 30 known species of seahorses, all of which belong to the Syngnathidae family. This family includes other unique fish such as pipefish and seadragons. Seahorses can be categorized into two main groups: spiny and smooth. Spiny seahorses have sharp spines or spikes covering their bodies, while smooth seahorses lack these spines. Both types of seahorses have a distinctive appearance, resembling creatures wearing body armor. Some examples of seahorse species include the yellow seahorse (Hippocampus kuda), also known as the common seahorse, which can be found in the Indo-Pacific region. In the UK, two species of seahorses are found: the Spiny Seahorse (Hippocampus guttulatus) and the Short-snouted Seahorse (Hippocampus hippocampus), mainly along the west coast and around Ireland.
Reproduction and Gender Differences
One of the most fascinating aspects of seahorses is their unique reproductive behavior. Unlike most fish, it is the male seahorses that go through pregnancy, not the females. The female seahorse transfers her eggs to the male's special pouch, where he carries them until they are ready to hatch. The gestation period for seahorses is relatively short, ranging from two to four weeks. Depending on the species, a male seahorse can give birth to a few dozen or over a thousand baby seahorses, known as seahorse fry. These tiny seahorses are only about 7mm in length when born and must fend for themselves from birth. The presence of a brood pouch is a distinguishing feature that helps differentiate between male and female seahorses.
Conservation Status
Seahorses face various threats, including habitat loss and climate change, which affect many other fish species as well. However, seahorses are also targeted due to their unique appearance and potential medicinal properties. Millions of seahorses are captured from the ocean each year for use in traditional Chinese medicine, despite the lack of scientific evidence supporting their effectiveness. Additionally, seahorses are often sold as souvenirs in beach resorts, contributing to their decline. Some seahorse species are more at risk than others, with the three-spot seahorse from the Indo-Pacific region listed as vulnerable, and the Cape seahorse from South Africa and White's seahorse from Australia listed as endangered.
Fun Facts about Seahorses
Here are some additional interesting facts about seahorses:
- Despite living in the ocean, seahorses are not strong swimmers. They rely on their dorsal fin, which beats at a rapid rate of 30-70 times per second, to propel themselves forward. They also use small pectoral fins for stabilization and steering. Due to their limited swimming ability, seahorses prefer to live in shallow waters and use their tails to cling onto vegetation or the seafloor.
- Seahorses have the ability to change color, which they use for camouflage and communication. Both males and females can change their skin color using sack-like organs called chromatophores, controlled by the nervous system and hormones.
- Seahorses have excellent eyesight and can move their eyes independently from each other, similar to a chameleon. This allows them to look forwards and backwards simultaneously, which is useful for hunting prey.
- Seahorses cannot chew their food and lack a typical stomach. Instead, they use their snouts to suck up food continuously throughout the day. Adult seahorses can eat between 30-50 times per day, while seahorse fry consume around 3,000 pieces of food daily. Their diet mainly consists of plankton and small crustaceans.
I hope this information provides you with a comprehensive understanding of seahorses and their unique characteristics. If you have any further questions or would like to learn more, feel free to ask!
