A Modern Guide to Buying Seahorses

Written By: | Date Posted: 04/15/2013 | 9 Comments |
Seahorses In a Tank

Choosing the right seahorse is imperative if you want to ensure you’ll be successful with seahorses.

Are you considering purchasing seahorses but are unsure of where to start or afraid they are too difficult? Seahorses do need a specialized setup, but are not nearly as hard to keep as they once were. Advances in breeding have given us seahorses that are fully adapted to life in the aquarium. This buying guide covers what every aquarist needs to know about purchasing healthy seahorses before making that leap.

Seahorses should reach sexual maturity before purchasing (3”-5”)

Mature doesn’t necessarily mean full grown, just to the age and size where sex is visually determined. In most commercially available species, that’s between 3”-5” (roughly 7.5cm – 13cm) uncurled, which is from the top of the head to the tip of their tail. Many overseas farms and novice breeders sell their seahorses far too young. Most fish stores don’t really know enough about seahorses to avoid buying these; so the myth of seahorses as a difficult fish to keep is never dispelled. All too frequently, store employees even tell customers they’re female due to the lack of visible pouch. What they are actually showing you is an immature seahorse that’s not fully developed yet. Unfortunately at such a young age, seahorses are not stable, and the stress of being moved is often too much for them. They also require many more feedings per day than larger seahorses, and frequently starve in the hands of either the fish store or the well meaning but ill-equipped hobbyist.

Many overseas seahorse farms do offer larger seahorses for sale, but somewhere in the distribution chain, only the smaller ones get purchased. I suspect this is due to stores being hesitant to spend a lot on fish that are considered difficult, have a high mortality rate and are slow to sell because they can’t just go in any old tank. Ironically, buying these smaller seahorses ends up perpetuating the exact cycle of having high mortality and not wanting to spend more on larger seahorses.

Keep in mind that 3”-5” inches is a guideline; I’ve seen a number of larger seahorse species that have been sold at right around 3” but they are still far too young; species such as H. kelloggi, H. ingens and H. taeniopterus (often labeled as H. kuda) need to be on the larger end of the scale.

Small seahorse compared to quarter

This seahorse is far too young and it’s chance for survival is low even in experienced hands.

You can also try to determine if a seahorse is old enough by it’s body shape. While this isn’t an exact science, what you’re looking for is thicker bodies, more proportional heads. Young juveniles tend to be very thin, and don’t start bulking up until they reach maturity. The following guide gives some examples of the differences between an immature juvenile, and juveniles that have reached maturity.

Immature vs mature seahorse illustration

There is some variation but this look at immature and young mature animals should help serve as a guide for picking out your seahorse.

Only purchase true captive bred seahorses

It’s important to start with the strongest, hardiest seahorses and to do that you need ones that have been born and raised in captivity, from parents in captivity. They are adapted to life in the aquarium and are healthier, and eat frozen food. Sadly, many places conflate “tank raised” and “captive bred” even though they are very different things. Tank raised seahorses are those that are raised in unfiltered seawater or even net pens; so they have many of the same disease wild seahorses carry.

And never buy wild seahorses – aside from depleting them from their natural environments; they don’t adapt well to captivity. Avoid them at all costs; they have a poor record of survival in home aquariums. I’ve seen claims to the contrary with certain species, but if you follow various forums, even the ones considered by many as “hardy” still have a fairly high mortality rate.

If purchasing from a fish store, you need to verify the seahorses are actually bred in captivity. As mentioned above, many stores and even distributors confuse tank raised and captive bred. If you are unsure, ask where they were obtained, and if it’s not a local breeder, you should be able to research the company online. If you have any doubts about a seahorse’s origin, you should pass.

Don’t buy seahorses that are kept with pipefish

As of the publication of this article, there are no commercially available captive bred pipefish. Pipefish, being a relative of seahorses, can carry diseases that a captive bred seahorse has no resistance to. They are also likely carrying parasites that are easily transferred to seahorses. In essence, purchasing captive bred seahorses that have been kept with wild pipefish are undoing many of the things that make captive bred seahorses so hardy. Yet many stores do mix them; thinking that the two make good company. They may some day as we see captive bred pipefish readily available, but they aren’t now.

The same goes for other syngnathids (seahorse relatives) and wild caught or tank raised seahorses being kept with true captive bred seahorses; if they’re mixed or have been in a system which recently housed both, they are at risk of infection.

Don’t buy seahorses being kept with other fish.

Most fish stores these days do a good job of keeping aggressive fish from seahorses. However, even non-aggressive fish though can pose a significant disease risk. While they aren’t necessarily as virulent as wild caught syngnathids (seahorse relatives), they still can carry pathogens that cause problems, such as ich. Ich is invisible on seahorses as it only affects their gills. Unfortunately, the process of treating seahorses for this is lengthy, cumbersome and not without risk. And that is if you’re lucky enough to realize it is a problem, since it is essentially invisible.

Be wary of shared systems, not just what is in the tank. Many fish stores have their tanks connected to make tank maintenance easier. Unfortunately that can allow pathogens to circulate freely into other aquariums, including the one housing seahorses.

An exception to this rule is captive bred fish with a gentle demeanor, such as gobies.

Seahorses should be kept at lower temperatures

Seahorses are very sensitive to bacteria, and bacteria proliferate at higher temperatures. It surprises many people to learn that even tropical seahorses shouldn’t be kept at reef temperatures. They should be kept between 70-74F(21-23.5C). Any warmer than that and they risk disease, even if only kept at those temperatures for a short time.

Paying extra for color may be a waste of money

Seahorses change color. Yet amazingly, many vendors charge more for more colorful seahorses, and many people pay that premium. This makes sense in fish that stay the same color, but seahorses can change at the drop of a hat. You can walk out of a store with a seahorse one color, and have it be another in the time it takes you to drive home. Because they use color to blend into their surroundings, it’s almost guaranteed they will change color when moved to a new environment.

There are several vendors that are now selling “pied” or “pinto” seahorses for large sums of money. In every case reported, those fish turned normal colored. It does seem to be a distinct trait, but it almost always goes away as the animal ages. Unfortunately, some unscrupulous breeders claim the color is set and there are a number of very angry keepers who spend a large sum of money on now normal colored seahorses.

Young pied seahorse assumes normal coloration as an adult

A pied seahorse shown changing to normal coloration in adulthood. Photo courtesy of Louise Hines

If you decide you want to pay a premium for color; then just go into it knowing that it is likely to change. Seahorses are often raised in bright blue tanks with brightly colored hitching posts to influence color. Most aquarists prefer a more natural look, which means duller colors in the aquarium, and seahorses will often match that. But even brightly colored aquarium decorations don’t guarantee bright colors; seahorses just do whatever color they want to do and may decide that their favorite hitching post is the black filter tube in your aquarium, and they color themselves to match. Or they may decide to do contrast coloration, and have no bearing on what colors are in your aquarium.

Seahorse changes colors a lot.

Color change goes the other direction as well – a drab seahorse can become colorful. This is a prime example, it is the same seahorse, left when purchased, top right a few weeks after purchase and bottom is he’s current coloration. Color at time of purchase has very little bearing on the long term color of a seahorse. Photo courtesy of Catherine Harris

Don’t be fooled by trade names

Some suppliers try to increase the perceived value of their seahorses by giving them various names that make them appear to be different than a normal seahorse. One very popular one is to called wild caught Hippocampus reidi “Giant Brazilians” or “Giant Reidi”. They are larger than what most people see with H. reidi because they are full grown adults. They are not a different species or a distinct strain and do not produce larger offspring as often reported. And being captured from the wild, they also tend to fare poorly in captivity. Some people claim success with them, but many more have had trouble with feeding, spontaneous deaths, and wasting disorders.

Other companies give their seahorses cutesy names in an attempt to make them stand out over “normal” seahorses, possibly attempting to cash in on the designer clownfish craze. To date, there aren’t any established varieties of seahorses; any special name should be looked at skeptically if there is a surcharge for ‘named’ seahorses.

Seahorses should be active and looking around

Contrary to popular belief, seahorses are quite active. Even if they’re hitched in one place, they are usually looking around and scouting for food. Some may be nervous about being watched, and slow down, trying to orient their bodies so their back is facing you, with one eye peering behind them. But what you don’t want is a seahorse that just sits in one place, staring ahead with no activity. That’s a sign of an unhealthy seahorse. Because they do use stealth to hide from predators, be sure to view the tank from several feet back if you are unsure.

Seahorses should be eating frozen mysis

Many fish stores, for whatever reason, only end up offering their seahorses live or frozen brine shrimp. Or they get ones that haven’t been fully trained on frozen mysis. In some seahorses, they may lose the taste for mysis if offered live, even though it is the healthier food. Conversely, a seahorse that isn’t feeling well may not eat.

Ask the store to feed the seahorses mysis and make sure you see the one you’re interested in eating, not just targeting food. A seahorse may chase down food, but then once they identify it as non-living, give up and swim off. It may take some patience, as seahorses can be slow about finding food. But if it’s not eating at all, pass.

Seahorses should look well fed but not bloated

Many stores do not have the time to feed seahorses and verify that they’re eating properly. This is especially true with seahorses that are too young, and need to be several times a day. If the seahorses have been in a store for a few weeks, they may have already suffered from malnourishment at the hands of well-meaning, but ill-informed staff. If they’re only offered unenriched brine shrimp, it’s entirely possible for a seahorse to eat and still starve. And it’s not uncommon for stores to try and only let a seahorse forage food brought up by refugiums or offering copepods (too small and too few). Some might even offer mysis, but just aren’t able to take the time to watch them and make sure that the seahorses actually eat.

Starving Seahorses.

The signs of a seahorse that is underfed can be difficult for a novice to detect.

It can be challenging for someone not intimately acquainted with seahorse physiology to recognize a starving seahorse. What you want to do is ignore the stomach and look at the tissue between the rings; a seahorses body is made up of boney plates covered by tissue. A starving seahorse will begin to lose muscle mass and the rings will be very pronounced. A well-fed seahorse, you will be able to identify the rings but they will not be overly protruding.

Severe muscle waisting in a seahorse

An extreme example to show what muscle wasting looks like on a seahorse. Notice the empty, flat area between the bony rings. Most of the time, signs of starvation will be much less obvious.

Stringy white feces is a sign of a malnourished seahorse, which may be from a lack of food or from intestinal worms. It’s not uncommon to see this in seahorses that have just been shipped (many shippers withhold food for a day or two to ensure they don’t foul the water en route) but if they’ve been at the store for more than a couple days, they should not be experiencing stringy poop.

You don’t necessarily want a fat seahorse either; some forms of disease make a seahorse bloated. However, it’s easy to confuse with well fed, or a female full of eggs. Chances are, if it’s a juvenile you shouldn’t see any really round bellies yet that push out past the rings.

Healthy Seahorse

This is a healthy looking seahorse – a good amount of mass between it’s body rings, but not bloated in appearance; you can still easily see the body rings.

Watch out for signs of disease

Many seahorse illness are subtle in the early stages and take a skilled eye to determine if there is a problem. While there are more illnesses than the scope of this article can cover, there are a few symptoms that are commonly problems in seahorses available in shops:

Stiff Tail, Tail Standing

Usually early signs of tail rot. A seahorse should be willing to wrap it’s tail completely around a hitching post or let it drag across the ground. Tail standing is when they curl the tip up and try to balance on the non-injured end. A stiff tail, i.e. one where the end sticks out straight and doesn’t touch the hitching post is another sign that their tail is sensitive because of an infection.

Early signs of tail rot.

Early sign of tail rot. The seahorse keeps the tail bent at an odd angle when swimming (left) and keeps the tip off the ground (right). Also notice the stringy white feces, a sign of malnourishment. Photo courtesy of Miss Nano.

Flesh Erosion

Flesh erosion is patches of skin that are inflamed because of infection. They can be white, grey, yellow or red. They can be tough to distinguish from normal coloration, especially if a seahorse has saddles, which is normal coloration across the sides and back of the seahorse. In general, you’ll want to look for rough or flaking skin, but also look to see if any patches are symmetrical on both sides of the seahorse.

Compare disease to healthy seahorse

The picture on the left shows a seahorse in the early stages of flesh erosion disease, whereas the seahorses on the right are showing normal coloration. The irregular blotches along the back are called “saddles”.

Coughing, Yawning and Gilling

Gilling the term used to described breathing heavily. It looks as though they’re attempting to drink water. This is a sign of respiratory distress, which may either be from water conditions or some sort of infection of the gills (parasites, bacteria or fungal.)

Coughing is very similar, except the seahorse seems to jerk its mouth open at random intervals as well as jerk suddenly. This is usually a sign of discomfort. If it’s during feeding, they may have a piece of food stuck in their mouth. At other times, it’s the sign of a problem. Yawning often goes along with coughing. They will stretch their mouths and drop the trigger so it’s pointing perpendicular to the ground. Doing this one in a while is not an issue (some seahorses do this when excited), but if it happens numerous times or in conjunction with coughing or gilling, it’s usually going to be a sign of problems.

Avoid rescuing seahorses

It may be hard to see a seahorse that is being poorly cared for in the hands of callous staff. However, you should never purchase any seahorse that isn’t 100% healthy, even at a discount. Doing so only encourages the store to buy more and do the exact same thing again. I’ve been given free sick animals to try and treat (though I no longer do this), but would not pay for one for the exact reason. It may be heartbreaking, but by buying the ill or mistreated one, you’re dooming many more to the same fate.

Sick seahorses are also very difficult to turn around. The key to success with seahorses is obtaining healthy animals from the beginning and preventing illness. Seahorses have a primitive immune system, so once illness strikes, it’s often fatal even with the best care and treatment.

Sometimes the best place to purchase seahorses is directly from a breeder

Many aquarists are first introduced to seahorses as pets through their local fish store. They see these amazing, adorable fish and for the first time realize they can have one themselves. So they get a tank started, get a seahorse, and then everything goes sideways. Either the seahorse gets sick, doesn’t eat, or ends up in a tank where it’s bullied.

Fish stores have long been fountains of terrible information about seahorses. They recommend tanks too small and temperatures too high. But beyond that, they’re usually not a good source for healthy seahorses either. I’m sure many store owners and employees would argue otherwise, but seahorses have specialized requirements and very few shops are able to dedicate the time and space to their needs. And many more just don’t know enough about those specialized needs to do well with seahorses in their care for even a short while.

Of course there are always exceptions, but they are few and far between. The rare stores that have healthy, true captive bred seahorses that are well cared for generally have an employee who has taken special interest in seahorse and has advanced knowledge of their care. Most stores may sound like they know what they’re talking about, but don’t be fooled; they speak from authority because a large part of their job is giving advice. If you are being told anything counter to this list, then run far, far away.

Breeders tend to be the best at ensuring you’re getting exactly what you are looking for. They’re going to know the species they are breeding, and you’re less likely to have mistakes in identifying the sex of the seahorse you are getting.

A word on the confusion over terminology

Tank Raised Vs. Captive Bred Vs. Wild Caught VS Tank Bred

Seahorses used to be extremely difficult to keep in captivity. They didn’t eat, they died at the drop of a hat, they broke our hearts. This is because they were captured from the wild, and as a group of fish, just did not adapt well to aquarium life. For the past 10 years, seahorses raised in captivity have been readily available in most countries, making it much easier to keep them. However, how they’re raised is almost as important as if they are captured in the wild or raised in captivity.

Wild Caught. Wild caught means exactly as it sounds, they were captured from the wild. They are usually stressed, harboring parasites, and refused to eat anything but a limited selection of live food. Because capture and transportation is so stressful to a fish that lived in the ocean it’s whole life, they often stop eating or contract a secondary bacterial infection.

Tank Raised. Tank Raised is a confusing and misunderstood category of captive reared fish. At it’s core definition, it means raised in a tank. What it usually means in practice is that the parents were not in captivity, and the fish in question was either harvested in a larval or post larval stage and then raised up to the point where it was big enough for sale. In the case of seahorses, because of their unique biology, it often means a pregnant male is capture and placed in a tank for birthing, and then the young raised.

Captive Bred. Captive bred means born and raised in captivity, and the parents were established and comfortable enough to mate in captivity. It can mean the parents were wild caught and acclimated to captivity, but more and more frequently it means they are many generations in captivity. It also means they were raised in an entirely captive environment using either artificial seawater or filtered and sterilized seawater.

Captive Bred Seahorses are by in far the hardiest of the seahorses you can get.

Always choose captive bred seahorses.

The mixing of the terminology

With seahorses, the terminology gets complicated. Tank raised has taken on a slightly different meaning. Tank Raised is used to denote a seahorse that has been raised in captivity, but haven’t been kept free from pathogens because either they’re being raised in tanks or tubs filled with unfiltered ocean water, or they’re raised in pens made of netting that float in the ocean. These seahorses are often trained to eat frozen food, so they are a little easier to care for than wild caught seahorses. However they can have parasites and carry virulent strains of bacteria.

So even if a seahorse is technically “captive bred” but is exposed to unfiltered seawater in it’s rearing process, it’s considered tank raised. Additionally, the ones that are considered “tank raised” are sold much too small so tend to fare very poorly in captivity. The stress of transportation at that age, combined with exposure to natural seawater is a recipe for disaster for the unwary aquarist.

Other terms to confuse the matter are “tank bred” and “captive raised”. In theory “tank bred” should be the same as “captive bred” but it’s often meant to mean “tank raised”. Same with “captive raised”; it should mean only raised in captivity, but not necessarily bred there. Many of these phrases have been unintentionally jumbled as for some fish it doesn’t make a differences. For seahorses, it is vitally important, and if there is any doubt, do not buy.

True Captive Bred” Seahorses has become the terminology that many seahorse breeders use to denote that they are aware of the nuances and importance of seahorses bred, born and raised in captivity as opposed to the various ways the terminology is used and misapplied. However it is still important to verify the source is a reputable breeder – like any other specialty, it’s only a matter of time before unscrupulous sources realize the value of this phrase and start applying it incorrectly to make a sale.

An additional word on Wild Caught seahorses.

Wild caught seahorses still make their way into the trade far too often. Unfortunately, many people incorrectly believe they are illegal to harvest, and therefore do not realize that it is still possible to see wild caught seahorses available for sale. Generally they don’t handle captivity well, and they can additionally harbor bacteria and parasites that spread to seahorses not raised in the wild. Below is a list of species that regularly make it into the trade from the wild:

In the US

H. erectus; common name Lined Seahorse or Black Seahorse
H. reidi; common name Brazilian Seahorse, Reidi
H. zosterae; common name Dwarf Seahorse, Pygmy Seahorse

In the EU and UK

H. reidi – common name Brazilian Seahorse, Giant Brazilian Seahorse
H. barbouri – common name Barbs, Barbouri, Zebra Snout Seahorse
H. whitei – common name White’s Seahorse
H. abdominalis – common name Pot-Belly Seahorse

In Australia

H. subelongatus – often mislabeled H. angustus

What to do if you’ve discovered this list after purchasing your seahorses

So, you’ve got a new seahorse, and it’s about the size of your pinky. You’ve realized it is immature, tank raised or even wild caught, and not sure what to do; or if you should do anything at all.

My recommendation, in all honesty, is to return it to the fish store you purchased it from. These seahorses have poor survival and cause a lot of heartache to the aquarists who try their hardest to do right by them. Fish stores will not stop carrying them until they stop making money on them, and if you’ve already purchased them, the only recourse is taking them back. But understandably, many people opt not to do that.

So if you decide to keep them, what you’ll need to do next depends on both your current setup and what size your seahorses are. If you’ve purchased seahorses and they are very small, you will need to treat them as a breeder would; you’ll need to feed them 3 to 4 times a day. You may need to get smaller food than what is readily available, and you should be prepared to enrich adult live brine shrimp for them. Frozen mysis from hikari tends to be very small in the winter. Omega Sea has mysis that are rather small, though they are usually somewhat dirty, so be sure to rinse well. Dan’s Feed with Beta Glucan from Seahorse Source is the enrichment I would recommend using if you use live brine shrimp while they are growing.

If they’re in a large aquarium, or one with a lot of decorations, you may want to consider moving them to a bare bottom 10 gallon aquarium with a few easy-to-clean hitching posts. If they are very small, this will help ensure they’re getting the right food and enough food. Chances are the place where you purchased them were not feeding them often enough, so you’re going to need to make up for lost time. The 10 gallon should be cycled, so buy a quality refrigerated bacterial starter or use established filter media. It will only be a temporary home as your seahorse will require a tank of 30 gallons or larger depending on the species (the exception being dwarf seahorses).


You should take this as an opportunity to deworm the seahorses as well. Seahorse.org has a good protocol for quarantining and deworming:

Deworming is a 9 week process in a hospital tank. You will need live adult brine shrimp, praziquantel, fenbendazole, and metronidazole. A small handmixer or blender is helpful.

For the first 3 weeks, one day each week, feed two meals of adult brine shrimp gutloaded with fenbendazole to the seahorse(s).

  • Brand names=panacur, safe-guard
  • if using granules, thoroughly mix a 1 gram packet (1/4tsp) in one gallon of water.
  • if using 10% liquid solution, thoroughly mix 250mg (2mL or 1/2 tsp) in one gallon of water.
  • place one feeding worth of brine shrimp in the mixture and leave them for at least 2 hours.
  • add brine shrimp to the tank and observe to make sure the seahorse is eating them.

For the second 3 weeks, one day each week, feed two meals of adult brine shrimp gutloaded with metronidazole to the seahorse(s).

  • Brand names=Metro+, Metro-Pro, Metronidazole, Metro-MS, Flagyl
  • if using tablets, crush one tablet into a fine powder and thoroughly mix in one gallon of water.
  • if using powder, thoroughly mix 1/4 tsp in one gallon of water.
  • place one feeding worth of brine shrimp in the mixture and leave them for at least 2 hours.
  • add brine shrimp to the tank and observe to make sure the seahorse is eating them.

For the third period of 3 weeks, one day each week, feed two meals of adult brine shrimp gutloaded with praziquantel to the seahorse(s).

  • Brand names=PraziPro, Praz-tastic, Praziquantel
  • Thoroughly mix 10mL (2 tsp) of praziquantel in one gallon of water.
  • place one feeding worth of brine shrimp in the mixture and leave them for at least 2 hours.
  • add brine shrimp to the tank and observe to make sure the seahorse is eating them.

If you’re lucky enough that your seahorse is large enough it doesn’t need the same coddling as juveniles, you should consider deworming anyway. If you choose not to deworm, then it become very important to watch your seahorse for signs of wasting and flesh erosion. This can occur at any time; a seahorse might be fine for years before any stressor can cause a seahorse’s immune system to be compromised and vulnerable to parasites it’s been carrying.

You’re not guaranteed success by deworming, but it does help curb problems later down the road.

It is vitally important that you are aware if you have purchased a smaller seahorse, that it will need a larger tank when it starts to grow. Many fish stores sell the very tiny juveniles and insist they can be kept in nano tanks as small as 4 gallons. If properly fed, they will outgrow that in a month. If improperly fed, they’ll likely waste away and die, hence perpetuating the myth about difficult seahorses.

If you find yourself in this bind, and have questions, please sign up at our forums and we will be happy to help you get everything setup correctly.

Lined seahorses mature juveniles

Several young but mature seahorses available at a frag swap from a breeder.

9 Responses to “A Modern Guide to Buying Seahorses”

  1. Donna Says:

    Thank you for writing such a great article! So much information and such beautiful picture’s too!

  2. Edd Says:

    Very well written and informative guide to seahorse keeping :)
    This should be given out to every shop and keeper so people can look after and appreciate these animals the way they should

  3. Tami Says:

    Thanks Edd and Donna. And that’s a great suggestion, sending to fish stores. Actually Louise from http://seahorseadventures.blogspot.com and I have been discussing the specifics of writing one for fish stores. It would need to vary a bit but the core ideas would be the same. But in the meantime, feel free to print it up and show your LFSs!

  4. Andreas Says:

    Great artikle !
    Nicly composed and summarised !
    greetings and thumbs up from Croatia !
    Andreas

  5. Sharyn Says:

    A very informative site, especially for a new starter on the verge of setting up a seahorse tank.

  6. arshad ali Says:

    i want no the information about seahorse how to take care how to cure disease and how to breed the saehorse

  7. Aquagrrl Says:

    Hi Arshad, you may want to join our forums to ask these questions, they’re more in-depth than can easily be answered in the comments section.

  8. Elaine Says:

    I don’t know how many times over the last year i have read this. Each time i have taken more and more in. Not panicking when reading it now so i must be ready :)
    Great article,
    Elaine

  9. sue Says:

    Well done,I will take a copy to put with my other information,it’s helpful when others ask how to get started.

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More in Aquarium Care (2 of 16 articles)