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Related FAQs: The Brackish to Freshwater Pipefishes, Seahorse Selection, Seahorse Systems, Seahorse Compatibility, Seahorse Feeding, Seahorse Disease

Related Articles: Freshwater and Brackish  Pipefishes by Bob Fenner, Brackish Water Fishes, Pipefishes in General

Freshwater Seahorses? Fresh and Brackish Pipefish: A Challenge For the Advanced Aquarist


By Neale Monks  


While there is no such thing as a truly freshwater seahorse, though a few do inhabit estuaries, the closely-related pipefish family includes a number of freshwater species that can make good aquarium fish. However, they are not commonly stocked in tropical fish stores, primarily because they are difficult to feed, meaning that retailers lose too many specimens to make them economically worthwhile. But they do appear on most importers and wholesalers lists, so getting them through your retailer as a special order is often the easiest way to obtain these unusual and fascinating fish. The question is, are freshwater pipefishes the right fish for you? Charming as they are, these aren't fish for the inexperienced or casual fishkeeper; let's remind ourselves why.


Pipefishes and seahorses compared

Pipefish and seahorses are in fact very closely related, the main differences being in the orientation of the animal. Seahorses, the family Hippocampidae, have adopted a vertical posture, and use their prehensile tails to attach themselves to things like seagrass leaves and bits of rock. This allows them to steady themselves against the ambient water currents, and so move carefully and deliberately as they search for food. In contrast pipefishes, of the family Syngnathidae, retain the normal horizontal posture of most other fishes, and are much more active swimmers. But in most other respects the pipefish and seahorses are very alike. They have the same horse-like head, and in both fish the body is protected by armour plates. Like seahorses, some pipefish even have a prehensile tail that they will use to hook onto things when they want to rest.

A peculiar characteristic of both fish when compared with other bony fish is their mode of reproduction, with the male carrying the eggs in a brood pouch. In seahorses this pouch has only a small opening at the top, but in pipefishes it isn't quite so well developed. Among those pipefish considered to be more primitive, the pouch is little more than a sticky area on the belly of the male that the eggs can adhere to, but in the more advanced species folds of skin or armour plates extend across the eggs as well. A few pipefish (and all the seahorses) this one step further, with the male not only protecting the eggs but also providing the embryos with nutrients and oxygen as well, effectively mimicking the mode of reproduction of more familiar (and female) livebearers like guppies and mollies. A useful spin-off to this mode of reproduction is that while the eggs are sealed up inside the male pipefish's brooding pouch, they are isolated from the fluctuations in salinity and water chemistry on the outside. So estuarine pipefish are able to freely swim between fresh, brackish, and salt water without any harm coming to the developing eggs or fry.


Feeding pipefish

Pipefish, like seahorses, are very specialised predators. They have evolved to move slowly and stealthily through vegetation unnoticed by their prey, which is usually small crustaceans, aquatic insects, and very small fish. Once they have approached the target, they rapidly expand their buccal cavity (their 'cheeks') sucking in their prey along with the water. This mode of feeding allows them to capture animals that other fish might miss or be unable to grab using extensible jaws, making them very effective if rather slow predators.

Having looked at how they eat, it should come to no surprise that just as with seahorses, the big problem with keeping pipefish is feeding them. Because they hunt slowly and stealthily, the can't compete with more active species in the usual aquarium free-for-all at feeding time. If you think bumblebee gobies and glassfish are reticent and picky feeders, then pipefish will be a very unpleasant surprise! Really the only way to keep them well fed is to ensure that they are the only fish in the tank, and that they are regularly offered plenty of live, or possibly frozen, foods. This can most easily be handled by surrounding them with small crustaceans and insects collected from clean streams and rivers and allowing them to pick off whatever they want at their own pace. Smaller pipefish appreciate things like Daphnia, while the larger species will also enjoy larger prey animals such as Gammarus ('scuds'). Pipefish of all sizes readily take live bloodworms and mosquito larvae as well.

In recent years many aquarium stores have started to carry live river shrimps (usually various Palaeomon and Palaemonetes species) collected from fresh or brackish waters, but you can also collect your own if you need to. These make an excellent staple diet for both pipefish and seahorses, and are not particularly expensive either. Because they can survive in fresh or brackish water almost indefinitely, they can be added to the tank and left to act as scavengers and algae eaters until the pipefish decide to eat them. Freshwater shrimps do tend to be sensitive to low oxygen concentrations though, and when alarmed to have a tendency to jump out of the aquarium if they can.

A possible alternative to live crustaceans is the use of baby fish, in particular young livebearers. This is really only viable if you happen to be breeding these fish on at least a fairly substantial scale because you're going to need dozens of baby fish to keep two or three pipefish well fed for a week. On the other hand, because the fish are fine in either fresh and brackish water along with the pipefishes, it's easy enough to keep them alive until they're eaten.

Failing a regular supply of live crustaceans and other small animals, what other options are there? Brine shrimp, whether live or frozen, are, unfortunately, a stop-gap food at best; just as with seahorses they are not nutritious enough to be used as a staple diet. One workaround is to 'load' the brine shrimp with nutritional supplements before feeding them to the pipefish, but this is a hassle the home aquarist probably won't want to get embrangled in. Frozen mysids and krill are a much better bet; mysids in particular are a major part of the diet of most marine pipefish and can therefore be expected to provide them with all the nutrients they need. Large species of pipefish in public aquaria and laboratories are routinely maintained on frozen mysids; the problem of refusing frozen foods appears to be most prevalent among the smaller tropical species. As with seahorses, part of the trick is eliciting the striking response -- once the pipefish has the food in its mouth, it'll most likely swallow it. Getting the frozen foods moving about in the water will help, as will mixing frozen foods with live foods, at least to begin with. Mixing live brine shrimp, for example, with frozen mysids would be a good way to begin. Feeding pipefish small, frequent amounts seems to be helpful as well: in public aquaria a wide range of pipefish have been trained to take meals of frozen mysids and krill at least 2-3 times per day, and using such a regimen have not only kept their pipefish alive but have even bred a considerable range of species.

Thus, anyone considering keeping pipefish needs to consider how they are going to keep them fed. Since these fish are so rarely held in stock by even the best retailers, it's not a question of simply asking what the retailer is giving them and watching them feed. Rather, you will need to read around the subject (books and articles on seahorses are especially valuable) and make at least a short-term plan whereby you can get a regular supply of suitable live foods, whether these will be shrimps, Artemia, or insect larvae until such time as your pipefish are fully trained to accept frozen mysids and krill.


Aquarium requirements

Most pipefish are marine but several inhabit fresh and brackish waters. The freshwater species prefer neutral, moderately hard water and will not do well in soft, acidic water. The brackish water species need hard, alkaline water with some salt added and should not be acclimated to completely fresh water. All pipefish are intolerant of poor filtration and low oxygen levels, and it is essential that any aquarium containing these fish is mature and stable. None of the pipefish can really be considered 'hardy' in the sense of being tolerant of rapid changes in water chemistry or less than optimal filtration, though the large brackish water species Microphis brachyurus is a little more forgiving than the other species.

As far as decorating the tank goes, the aquarist needs to bear in mind that these are not open water fish, and in the wild they tend to keep close to vegetation and other sources of cover. Therefore plants, bogwood, and rocks should all be used creatively to build a complex habitat that will allow the fish to feel secure. At the same time, you need to make sure that uneaten food isn't going to collect somewhere that the water current can't reach, always a risk when you put a lot of plants and stones on the substrate. Plants like Vallisneria and Sagittaria are ideal species to use in the pipefish aquarium: their long, thin shape complements the fish nicely and their tolerance of alkaline and brackish water allows them to thrive in the conditions that many pipefish like. Pipefish aren't too concerned about lighting levels provided there is a mix of bright and shady regions that they can move between as the wish. Allowing the leaves of some of the rooted plants to grow across the surface of the tank would be one way of doing this, but otherwise use clumps of things like Ceratophyllum submersum and Ceratopteris thalictroides.

The size of the aquarium is tricky. Some pipefish are relatively big animals, the coldwater species Syngnathus acus for example easily tops 45 cm (18 inches) in length. But many are quite small animals, especially given the fact that they are all long and thin creatures without much bulk. So like any other fish, you will want a tank that gives the pipefish space to swim around in. However, one lesson to be learned from public aquaria is that the smaller the tank, the higher the concentration of food around the fish and the better it feeds. Thus the aquarist needs to make a careful balance between having a tank big enough for the fish to be comfortable but not so large that it cannot find its dinner. A group of three of four smaller pipefish, like the 15 cm (6 inch) Enneacampus ansorgii would therefore be best suited by quite small tanks with a volume of 20 to 30 gallons. Larger fish such as Microphis brachyurus, which can top 20 cm (8 inches) when fully grown, would need somewhat larger quarters, something around the 40 gallon mark.



For the very best chance of keeping these fish successfully, you will want to keep a school of these fish alone, or else with small animals like shrimps that are meant to be food as much as decorations. Slow moving or filter-feeding things like snails and fan shrimps (Atyopsis spp.) would also be a no-risk option, but what about other kinds of ornamental fish? Species that feed exclusively from the surface, preferably on things the pipefish would ignore such as flake, are ideal. These could include things like hatchetfish and African freshwater butterflyfish. Halfbeaks are a bit more boisterous, but since they tend to ignore tough crustacean foods like mysids and krill, should work out okay. On the other hand, fast, opportunistic feeders like mollies, danios, and barbs would be a bad idea. These fish would likely gobble up all the food long before the pipefish ever found them.

Similarly, fish that feed exclusively off the bottom would work well, too. Not only would they not compete with the pipefish, they could perform a useful function as scavengers, snapping up any shrimps the pipefish overlooked. The 'earth-eating' Awaous gobies, Corydoras, and small plecs could all be considered for this housekeeping r"¢le. Animals that feed only at night, like kuhli loaches and freshwater flatfish would also work well, but avoid territorial or boisterous species like Synodontis and mormyrids.



Very few species of fresh- and brackish water pipefish are imported, and almost invariable they are members or the genera Enneacanthus and Microphis. In addition, brackish water species of Syngnathus can also be obtained, though these are primarily sold through biological suppliers for use in public aquaria, universities, and laboratories. The following are among those species that have most frequently been kept by aquarists, but this is by no means an exclusive list, and to some extent you will need to rely on your supplier for the Latin names (and requirements) of the species available to you.

Enneacampus ansorgii -- African freshwater pipefish

This is one of the smaller pipefishes and the species most widely traded, though sometimes under an obsolete Latin name, Syngnathus pulchellus. It is basically brown, darker on the top and paler on the sides and covered in light grey or yellow spots and squiggles. The most striking feature of the fish is its orange to blood-red belly, which is present on both males and females.

Of all the freshwater pipefish, Enneacampus ansorgii is one of the most seahorse-like in form, having a delicate, rather short snout, a deep, laterally compressed body, and a long, thin tail. It is also quite a sluggish fish, staying close to the bottom, and often on it, appearing at first glance to be rather like an eel. As it moves around the bottom of the tank, it will pick off benthic animals like bloodworms as well as things swimming about in midwater.

In the wild Enneacampus ansorgii inhabits both fresh and brackish water, but hard, alkaline, slightly brackish water appears to be the best option for long-term care in home aquaria. Presumably the additional calcium salts help to buffer against rapid fluctuations in pH. The amount of salt added need not be very high, only about one teaspoon of salt per gallon, and this salt concentration will not do aquatic plants any harm at all. In fact these fish do best in planted tanks.

Enneacampus ansorgii has been bred in captivity, though only rarely, and details are lacking. It is understood that this is one of the species where the male develops a substantial pouch that encloses the eggs, and he carries them around for several months. Regardless of its breeding behaviour, these fish should be kept in groups as they are quite sociable.

Microphis brachyurus -- short-tailed pipefish

Known as the short-tailed pipefish, this is a very widely distributed species including at least four different subspecies. Microphis brachyurus lineatus is an open water species most commonly found in floating seaweed in the tropical and subtropical Atlantic but can even be found in warm water currents running along the eastern seaboard of the United States as far north as New Jersey. A giant among pipefish, it can exceed 90 cm (3 feet) in length. Being so large and essentially oceanic, this fish is unlikely to be offered for sale to aquarists; it is also rather rare and considered to be a vulnerable species, so should not be collected either.

Another subspecies, Microphis brachyurus brachyurus, is found along the Atlantic coast of the Americas between Florida and Brazil. It is also found in Asia, from the east coast of Africa and Madagascar across to Japan, and imports of brackish water fish from this part of the world could quite possibly include this fish. This is a moderately large pipefish, growing to about 20 cm (8 inches) or so in length, but is still a good size for the home aquarium. In the wild these fish can be found in fresh, brackish, and marine waters, with the adults more likely to be found in completely fresh water than the juveniles. Even so, they are best kept in brackish or marine conditions.

Two subspecies come from Africa, Microphis brachyurus millepunctatus, and Microphis brachyurus aculeatus, and it is this second subspecies, often referred to by an old name, Microphis smithi, that is the second species of freshwater pipefish that you are likely to find on your dealer's lists. It is similar in size to Microphis brachyurus brachyurus and though it is tolerant of hard, alkaline freshwater for extended periods is perhaps best kept in slightly brackish water. In the wild it is invariably found in thickly planted regions, and in contrast to Enneacampus ansorgii tends to swim about in midwater more or less constantly. In tanks with lots of rooted and floating plants it is active and not at all shy.

All the subspecies of Microphis brachyurus are peaceful, sociable, and best kept with their own kind. Since they are quite a bit bigger than Enneacampus ansorgii they tend to be more adaptable when it comes to food. Small crustaceans are ideal, but it will also take livebearer fry, bloodworms, and with luck, frozen mysids and krill. Because these fish breed in the sea, and the offspring have a planktonic larval stage, reproduction in aquaria will be a complex proposition and has not yet been observed.

Syngnathus scovelli -- Gulf pipefish

Species of Syngnathus occur in fresh, brackish, and marine waters in both cold and tropical waters. Syngnathus acus, for example, can be found in the Thames Estuary in London. Many species in this genus have been collected by hobbyists from shallow marine environments and they have generally proved to be hardy and easy to care for. A few marine species have been bred successfully in public aquaria, but as yet, like the subspecies of Microphis brachyurus, reproduction in home aquaria has not yet occurred.

The Gulf pipefish can be found on the Atlantic coastline from Georgia to Brazil, but only ever in shallow water. Though hardly ever offered for sale through traditional tropical fish traders, it is common and not a protected species, so it can be collected from the wild (though you will need to observe the local and State laws). Biological supply companies may be able to obtain these fish for you and deliver them to your home if you cannot collect them yourself.

Syngnathus scovelli is truly euryhaline and adapts well to variations in salinity. Nonetheless, in aquaria this species is best kept in strongly brackish rather than fresh water. In the wild it stays fairly close to the substrate and takes prey such as amphipods, so the aquarist will probably want to focus on offering these fish live foods that crawl about, at least to start with.



Pipefish are interesting fish for the advanced aquarist with access to live foods. They aren't easy to keep, and not all specimens adapt to frozen foods. They need tanks with good filtration and very stable water chemistry. None of them are tolerant of anything other than completely peaceful tankmates, and even finding pipefish will take time and may involve placing a special order, and that's likely to be expensive. In fact pretty much all the warnings experienced aquarists give about seahorses can be applied to pipefish, so the title of this article doesn't just refer to their looks but to their requirements as well! Even so, these are truly wonderful fish, and like discus and Amazonian stingrays epitomise what the dedicated aquarist can achieve. They are amazing to watch, bizarre in form, and highly specialised in biology. If you want something to aspire to in fresh- and brackish water fishkeeping, look no further that these wonderful beasties.

Freshwater Seahorses  12/6/11
Hello all.  Hope you are having  wonderful holiday season!
<Thank you>
I have read and learned much from your site for a few years now.  I am extremely appreciative of the information you provide as well as the time you take to help others.
In respect of your time, I will get right to it.
I have scanned the internet as well as the WWM site about freshwater seahorses.  This has overall been considered a myth and I have found several spots on the site that claim there are no such things as a freshwater seahorse.  I have learned though, that in Lake Titicaca, in the Andes Mountains of S. America (at a height of 13,000 ft), there is a unique species of seahorse.
 No one really knows how it got there or what adaptations to a freshwater environment it has made.  Here is my question. How would a new species like this be collected and imported? 
<Gasterosteiform fishes are pretty easy to catch, being slow-moving...
though many are hard to find, being cryptically shaped, marked...>
Short of me going to S. Am myself, I can not imagine how to accomplish it.
Anotherwards, this species is obviously not available to the general market.  I would like to know how a few could be made available to me through responsible and consciensus channels.  I know that you all with your wealth of information and contacts might have a clue as to where to start. I know odd question, but we all like the rare and beautiful. 
<I have never heard/read of such a fish t/here. Do you have a reference you can send along re? There are a few barely brackish species of Syngnathids (Horses and Pipefishes), but no strictly freshwater species as far as I'm aware. Bob Fenner>
Re: Freshwater Seahorses  12/6/11

Upon my research, I am afraid this may be more of a cryptozoology problem.
I actually was interested in the seahorse following a show I saw on the History Channel talking about the submerged city in the lake.  There was a definite statement that the lake was the home of the only freshwater seahorse known to exist.  I followed up with internet searches/articles and like I said found many claims/pictures of this animal and there supposedly was one of a living specimen on the show.  I understand that because of the difficulties of diving in the area (due to its elevation), there haven't been a great deal of exploration for biologics in the depths of the lake. I also read of reports from the 40s and 50s of sightings by the scientific community, but I find it highly improbable considering the technology available in that era for high altitude underwater exploration.  I guess it would be an interesting trip to find out specifically if it exists.
Thanks for your time,
<Hello Deana. The idea of a "freshwater seahorse" comes up now and again among hobbyists. But unfortunately, no such beast exists. Several species of Hippocampus do occur in brackish water, typically in river estuaries, and these can survive for extended periods at salinities well below that of normal seawater. This comes as a surprise to many people who assume seahorses are delicate animals. In the wild, they're actually tolerant of quite broad ranges of temperatures and salinities, and the reason they *seem* delicate is because they're difficult to feed under aquarium conditions (or at least wild-caught specimens are; farmed ones are rather more accommodating). In any event, while there are freshwater Syngnathidae in the general sense, including some kept as aquarium fish, there aren't any truly freshwater Hippocampus as such, even if some species may, for short periods at least, tolerate low salinities for extended periods. Do read:
Cheers, Neale.>


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