Seahorses make lovely aquarium pets. There are over 40 species out there. You can choose between various sizes and morphs, so this unique-looking fish fits most aquarists’ tastes. Seahorses are also very gentle and shy, getting along well with other peaceful fish. Unfortunately, they’re also quite challenging to care for.
Most seahorse species need at least a moderate level of care. Seahorses are sensitive to water currents, acidity, and temperatures. They also need a special diet and require frequent target feedings. However, some species are more forgiving than others.
Whether you’re looking for a lower-maintenance seahorse or are on board for a challenge, you can still find a suitable species for your aquarium. Keep reading to see how the most popular species compare. I’ve included both challenging and moderate-care seahorses and the smallest and largest fish you can find!
Here, are some of the most popular aquarium seahorses you can keep as pets:
Longsnout Seahorse
- Scientific Name: Hippocampus reidi
- Care Level: Difficult
- Size: 6-8 inches
- Temperament: Peaceful
- Lifespan: 3-5 years
- Water Parameters: 70-76ºF, 8.1-8.4 pH, 8-12 dGH, 1.020-1.025 SG
The Longsnout Seahorse (Hippocampus reidi) goes by two other names. People may also refer to it as a “Brazilian Seahorse” or a “Slender Seahorse.” This large marine fish has a long, slender, and curved body, as you’d expect from any seahorse species. It comes in various beautiful colors, like red, orange, and yellow. Adults have dark spots across the body.
This is one of the largest seahorses kept in the aquarium hobby. Thus, it needs an equally large aquarium. You’ll need at least 30 gallons, and the tank should be at least 16” high. They prefer a low current and lots of sturdy decorations to hang onto.
This seahorse is a fussy eater and needs a carnivorous diet, preferably mostly live foods. You should feed them a combination of krill, Mysis shrimp, grass shrimp, and other small crustaceans. Some aquarists manage to train these seahorses to eat frozen foods, but it’s an uphill battle.
On top of that, Longsnout seahorses are ambush predators, so they need target feedings. They need to eat 2-3 times daily. Their complex eating behavior makes caring for them quite challenging. Apart from that, Longsnout seahorses are wonderful fish.
They’re slow and peaceful. They get along well with friendly fish and other seahorse species. Longsnouts thrive in community tanks alongside other mellow fish that won’t outcompete them for food. Keep them away from crabs and aggressive fish, though. Seahorses are passive and can’t flee fast enough when attacked. They have fragile skin and get injured easily.
Tiger Tail Seahorse
- Scientific Name: Hippocampus comes
- Care Level: Moderate
- Size: Up to 6 inches
- Temperament: Peaceful
- Lifespan: 1.5 years
- Water Parameters: 72-78ºF, 8.1-8.4 pH, 8-12 dGH, 1.020-1.025 SG
The Tiger Tail Seahorse (Hippocampus comes) is quite popular and easy to breed. These seahorses live alongside coral reefs in the wild, and coral is also a part of their natural diet. Keep this in mind if you have live rock in your aquarium.
This seahorse comes in a few different patterns, but yellow and black are the most common. This morph has alternating dark stripes, starting at the tip of the tail and going up the back. Males are darker, while females sport brighter yellow colors. Tiger tail seahorses also have small spine-like bones poking out on their faces and backs.
This species grows quite large and does best in an aquarium 30 gallons or larger. The aquarium should be taller than it is wide and include plenty of decorations to add height for the hanging seahorses. Like all seahorses, this species is a slow swimmer. It can’t hunt prey, so it relies on ambush tactics.
You’ll need to target feed this seahorse 2-3 times a day. Luckily, this species isn’t a picky eater. It eats various protein-rich foods like small feeder fish, small shrimp, plankton, and coral. Live foods are best, but they can also eat enriched frozen foods like Mysis shrimp.
Like most other seahorses, the Tiger Tail is gentle and harmless. They’re slow swimmers and slow eaters, so the best tankmates for them include slow and peaceful species of all kinds, other seahorses, and herbivorous marine fish. Tiger Tail seahorses are also nocturnal, so they won’t disturb the diurnal fish in the community tank.
Spotted Seahorse
- Scientific Name: Hippocampus kuda
- Care Level: Difficult
- Size: 5-6 inches
- Temperament: Peaceful
- Lifespan: 5-6 years
- Water Parameters: 72-78°F, 8.1-8.4 pH, 8-12 dGH, 1.020-1.025 SG
The Spotted Seahorse (Hippocampus kuda) is the most popular seahorse species. Thus, you’re going to see it under multiple different names. Other common names include Common Seahorse, Sea Pony, and Yellow Seahorse. Other synonymous scientific names you might see are Hippocampus fuscus, Hippocampus moluccensis, Hippocampus chinensis, and Hippocampus raji.
The Spotted Seahorse is on the smaller size, typically growing up to 5 inches. This seahorse has a smooth, rounded body with small bumps across the back. There are no boney spines sticking out, unlike in other seahorse species. Body color ranges from yellow to cream to very dark grey or brown and is accompanied by many tiny dark spots.
The ideal tank would be at least 30 gallons, with plenty of vertical space. Like other seahorses, this species is a slow swimmer. It prefers slow-moving water and needs plenty of decorations to anchor onto when tired.
The Spotted Seahorse has a tiny mouth and needs a carnivorous diet containing very small live foods. Common foods for them include daphnia, brine shrimp, plankton, and newborn fish fry. You should target-feed this fish four times a day.
This fish is mellow and extremely peaceful. In the wild, spotted seahorses are close to the bottom of the food chain. Their slow swimming, lack of defenses, and poor hunting skills make them easy prey for more aggressive species. Thus, you should expect this seahorse to be pretty shy.
When choosing its tankmates, avoid energetic or belligerent fish, as those could intimidate and stress them out. Avoid crabs and sea turtles; these are natural predators for spotted seahorses and seahorses in general.
Lined Seahorse
- Scientific Name: Hippocampus erectus
- Care Level: Moderate
- Size: 4-6 inches
- Temperament: Peaceful
- Lifespan: 1-4 years
- Water Parameters: 72-77°F, 8.1-8.4 pH, 8-12 dGH, 1.020-1.025 SG
The Lined Seahorse (Hippocampus erectus) is a diurnal species native to the Atlantic Ocean. If you’re searching for a very colorful and ornate seahorse for your tank, look no further! Lined seahorses come in various shades, including orange, green, red, yellow, brown, gray, and black.
This seahorse species typically has pale horizontal lines on its upper body, hence its name. Some specimens might also have tiny white dots on their body, especially on the tail. Lined seahorses have very noticeable boney coronets and eye spines. The average body size ranges from 4-6 inches, but some specimens can reportedly reach up to 7.5 inches in length!
The bare minimum aquarium size for a mated pair is 20 gallons, but up to 30 gallons is even better. The tank should be at least 18 inches high. Include plenty of hiding spaces and tall decorations. You should target feed lined seahorses 3-4 times a day.
This species has a smaller snout than other seahorses, roughly half the head size. However, they can eat a variety of small crustaceans, tiny mollusks, and fish fry, preferably live. Mysis shrimp, krill, grass shrimp, and newborn feeder guppies are all good choices for them. It’s also quite easy to train lined seahorses to eat frozen foods, as most specimens are captive-bred.
As for tankmates, you can’t go wrong keeping different seahorses together. This peaceful fish also gets along well with other slow swimmers and calm bottom-dwelling species. Small gobies, pajama cardinalfish, and royal grammas are just a few examples of compatible tankmates.
Pot Belly Seahorse
- Scientific Name: Hippocampus abdominalis
- Care Level: Difficult
- Size: Up to 14 inches
- Temperament: Peaceful
- Lifespan: 3-7 years
- Water Parameters: 64-75°F, 8.1-8.4 pH, 8-12 dGH, 1.020-1.025 SG
The Pot Belly seahorse (Hippocampus abdominalis) is also known as the “Big Belly seahorse.” This species is unique in a few ways. First, it’s one of the largest seahorse species we know. The average body size is over 7 inches, but some seahorses might reach up to 14 inches!
Secondly, both male and female seahorses have noticeable large bellies, a trait usually limited to male seahorses in most species. Male Pot Belly seahorses have a big, rounded pouch, while females have a pointy stomach.
Pot Belly seahorses have rounded cheek and eye spines and a short, blunt coronet. Color morphs include yellow, white, orange, brown, and gray. These seahorses typically have pale bellies and dark spots on the head and back.
Keeping this species is quite difficult. They need a lot of room due to their large size; 50 gallons would be the minimum. These seahorses also require lower temperatures than most other marine fish species. On top of that, they have the same requirements as other seahorses— slow water movement, plenty of hiding spaces, and vertical surfaces where they can rest.
Their natural diet is based on small crustaceans such as amphipods or copepods. You should feed them a similar diet in the aquarium. Other good food sources for them include krill, Mysis shrimp, and brine shrimp. Luckily, most specimens in the aquarium trade are captive-bred. This makes it easier to train them to eat dried or frozen foods.
Like other seahorses, this species is harmless and perfect for community tanks as long as its tankmates can tolerate the lower temperatures. This seahorse is also reef safe. Pipefish, small Gobies, and Blennies are peaceful tankmates with compatible water parameters.
Dwarf Seahorse
- Scientific Name: Hippocampus zosterae
- Care Level: Moderate
- Size: 1.5-2 inches
- Temperament: Peaceful
- Lifespan: 1-2 years
- Water Parameters: 72-78°F, 8.1-8.4 pH, 8-12 dGH, 1.020-1.025 SG
The Dwarf Seahorse (Hippocampus zosterae) is among the tiniest and most adorable of all seahorses. Not only that, but it’s also apparently among the slowest swimmers documented so far. This mighty fish reaches an astounding 5 feet per hour, which makes it slower than most snails, slugs, and starfish. The Dwarf seahorse still beats anemone, though, so there’s that.
The average body size of a dwarf seahorse is 0.8-1 inches long, but the biggest specimens might reach up to 2 inches. Color morphs include yellow, cream, green, and black. These seahorses typically have dark or white spots on their bodies. The coronet is short and blunt. This species has barely-noticeable head spines.
This is a very forgiving seahorse species. You don’t need to bend over backward to make this fish comfortable. First, you can keep a mated pair in a tank as small as 10 gallons. A smaller aquarium is actually advised, as it makes feeding easier for this slow-swimming fish.
You don’t need any special décor either. This tiny seahorse can hold onto small macroalgae and other medium-height plants in the tank. Like other seahorses, Hippocampus zosterae is an ambush predator. It feeds on live foods like small crustaceans, fish fry, and small invertebrates. You should target-feed the Dwarf seahorse 2-3 times daily.
Dwarf seahorses are harmless to most aquatic species. In theory, they’re excellent community fish for small aquariums. However, their poor speed puts them at a huge disadvantage. You shouldn’t keep this seahorse alongside other species. Small, non-aggressive marine snails are the only compatible tankmates that won’t outcompete them for food.
Pacific Seahorse
- Scientific Name: Hippocampus ingens
- Care Level: Difficult
- Size: 8-10 inches
- Temperament: Peaceful
- Lifespan: 4-6 years
- Water Parameters: 68-77°F, 8.1-8.4 pH, 8-12 dGH, 1.020-1.025 SG
The Pacific seahorse (Hippocampus ingens) is also called the Giant seahorse. You can probably guess why. This fish measures 8-10 inches on average, while the largest documented specimens are up to 12 inches long!
Pacific seahorses come in various natural shades, including brown, grey, green, and maroon; the brightest-colored ones are yellow. The morphs sometimes have pale or discolored spots on their bodies. Pacific seahorses have small, blunt spines and a short coronet.
As with most decent-sized seahorses, you’ll need a 30-gallon aquarium minimum for this species. Include ample vegetation and décor. The Pacific seahorse’s diet is similar to that of other related species. They eat similar foods in captivity as they do in the wild. The list includes small organisms like crustaceans, zooplankton, and small fry.
This seahorse is often captive-bred. You can feed them live foods and frozen or dried foods. You should target-feed them 2-3 times daily. They can live peacefully alongside calm, slow-swimming community fish and bottom-dwelling invertebrates.
Barbour’s Seahorse
- Scientfic Name: Hippocampus barbouri
- Care Level: Moderate
- Size: 4-6 inches
- Temperament: Peaceful
- Lifespan: not known
- Water Parameters: 73-78°F, 8.0-8.3 pH, 8-12 dGH, 1.020-1.025 SG
Barbour’s Seahorse (Hippocampus barbouri) is native to Southeast Asia and naturally inhabits mangrove swamps and seagrass beds. This species was first documented in 1908 by biologists David Jordan and Robert Richardson. Despite this, we still don’t know how long this species lives.
It could be because of the rapid decline in the wild Barbour seahorse population. Currently, this species is classified as threatened by the IUCN. However, thanks to its popularity, Barbour’s seahorses in the aquarium trade are now widely captive-bred. If it’s like most other seahorses, it could have a lifespan of up to 2-3 years.
This seahorse has short but sharp eye and cheek spikes. It also has short but noticeable downward-curling spines on its back. Its snout is pale, long, slender, and covered in thin dark stripes. Color morphs include white, gray, light brown, and yellow. Most Barbour seahorses have brown spots or stripes on their bodies.
In captivity, they need an aquarium of at least 30 gallons. They’re naturally drawn to macroalgae, grasses, and corals and like hanging onto these surfaces. Try including some in your setup. This fish is reef-safe, so it won’t damage live rock in the aquarium.
There’s not much information on their natural diet. However, in the aquarium, they accept a variety of small live foods like zooplankton and small crustaceans. You should target-feed them three times a day like you would most other seahorses.
Since these fish are captive-bred, you can easily feed them frozen foods. Ideal tankmates for Barbour’s seahorses include peaceful and slow-moving fish, other seahorses, large snails, and corals.
Bargibant’s Seahorse (Pygmy)
- Scientific Name: Hippocampus bargibanti
- Care Level: Moderate
- Size: Up to 0.8 inches
- Temperament: Peaceful
- Lifespan: 1-2 years
- Water Parameters: 72-76°F, 8.1-8.4 pH, 8-12 dGH, 1.020-1.025 SG
The Bargibant’s Seahorse (Hippocampus bargibanti), also known as the Pygmy seahorse, is among the smallest species in its genus. Not to be confused with the dwarf seahorse (Hippocampus zosterae), which grows up to 2 inches long! The Pygmy seahorse reaches an average size of just 0.79 inches!
This seahorse has a few unique traits. It has bumpy knob-like growths on its skin called tubercles. It also comes in only two morphs— pale yellow with orange tubercles or light grey with red tubercles. This alien appearance is handy as it helps the seahorses camouflage seamlessly with their natural environment. In the wild, these fish live exclusively among soft fan corals.
Unlike most other seahorses, Pygmies have soft, rounded bodies and blunt, wart-like spines and coronets. They also have very short snouts. Given their very small size, you can keep these seahorses in aquariums of just 10 gallons.
You should include corals in your tank to emulate the seahorse’s natural environment. I recommend peaceful corals with similar colors, such as red, pink, white, or orange. Some good options include Toadstool, Pulsing Xenia, Kenya Tree, Sun corals, Bird’s Nest, and Gorgonians.
Pygmy seahorses consume a carnivorous diet containing live foods. Choose feed that’s small enough to fit in their mouths, such as zooplankton, copepods, and amphipods. Target-feed them 3-4 times a day.
Remember that seahorses are very slow. Small seahorses are even harder to feed in a community tank. Most other fish would outcompete the Pygmy seahorse for food. However, Pygmy seahorses can live alongside peaceful corals, peaceful snails, and other small seahorses.
Conclusion
Seahorses are unique-looking fish with unique requirements. Most species prefer warm, alkaline water with a low current. All seahorses need plenty of vertical space, hideouts, and tall decorations to cling to. Most species eat similar diets consisting of small live prey like tiny crustaceans, young fry, and zooplankton.
The largest differences between species include appearance and body size. Body size plays the biggest factor in the ideal aquarium size and feeding frequency. If you have a small aquarium, I recommend choosing Dwarf and Pygmy seahorses. Otherwise, all of the species above make excellent marine pets.
