Seahorses: Everything You Need to Know to Have Them in Your Aquarium

Posted by Allie Layos
Longsnout seahorse known as Hippocampus reidi in a marine aquari

Seahorses are expensive and a bit time consuming, but a lot of fun. 

There's something special about seahorses. Maybe it's their proudly arched necks or the way they latch onto things with their tails, but they stand out from other exotic fish.

It's natural to look at them and think you "just have to have one" in your own aquarium. But as fun and interesting as they are, seahorses are relatively expensive to buy (about $70) and a bit high maintenance to care for. If you're truly thinking about buying one, it is vital to do your research.


One of the things that makes seahorses different from other fish is that they have an exoskeleton body covered with skin rather than scales.

For this reason they are more susceptible to injuries and infections than other fish. Their gills are less developed as well, making them less efficient at exchanging gas.

yellow seahorse

For these and other reasons, it used to be very difficult to keep seahorses as pets. When captured from the wild, they often lived just a few months before succumbing to infection or starvation. But thanks to captive breeding programs, it has become far easier to keep seahorses in aquariums. Captive-bred horses are weaned on frozen prepared food, are hardier, and almost always free of disease.

While there are over thirty types of seahorses that fall under the genus Hippocampus, the Smooth Seahorse (Hippocampus kuda) and the Lined Seahorse (Hippocampus erectus) are two of the most common ones sold as pets, followed closely by the Dwarf Seahorse (Hippocampus zostera). Larger seahorses live for about five years (some reports say up to ten!) while Dwarf Seahorses live for about two.


It is very important to set up your tank correctly for your seahorse. First, seahorses require a saltwater aquarium rather than freshwater. The tank should be kept between 74 and 76 degrees (cooler than required by most tropical aquaria), and shouldn't have a strong current or water movement, because seahorses aren't strong swimmers and their gills are not very efficient.

Seahorses are more "vertically oriented" than horizontally, so the height of your tank is more important than its width. A seahorse tank should be at least 18 inches tall.

When filling the tank, you'll need to include at least one hold fast or hitching post around which your seahorse can wrap its tail. This is important because it gives the seahorse a break from constant swimming. Faux corals or even plastic aquarium plants will work just fine.

white seahorse


The best food for captive-bred seahorses is frozen Mysis shrimp. Seahorses must be fed at least twice a day, and most require six to eight shrimp at each feeding. Very large seahorses may eat more, however, so you should monitor yours closely.

There are various feeding methods for seahorses. Some owners simply squirt some thawed Mysis into the tank and let the seahorses chase it around until they catch it, but it's easier for them if they don't have to work too hard to get their food. Turning the filter off during feeding or feeding them in a low water flow area of the tank can help. Some people also train their seahorses to use a feeding station.

red seahorseTankmates

Because seahorses are not aggressive feeders, it's important to keep only other slow, cautious eaters in their tank. Scooter blennies, firefish, Banggai and pajama cardinals, and royal grammas are often considered good tankmates for seahorses.

Seahorses are a little high maintenance when compared to many other fish, so it's important to familiarize yourself with their needs before making a commitment to care for one. If you do have the time and financial ability to take on the care of a seahorse, you're in for a fun ride!

What do you think of seahorses? Tell us below!

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Seahorses: Everything You Need to Know to Have Them in Your Aquarium