Often times when hobbyists are considering a species-dedicated aquarium, the idea of a tank full of seahorses is the first species of choice. For those interested in the "common" animals of the exotics, seahorses can be a fulfilling experience. They will certainly entertain your guests. However, there are those that prefer something less mainstream, an "uncommon" exotic, if you will. For those individuals I present the April 'Fish Tales' on pipefish.

Meet the Family

Pipefish are a small group of fish from within the family Syngnathidae, meaning 'jaw fused.' Although the Syngnathidae is commonly called the Pipefish family, the most notable fish of this family are in the subfamily Hippocampinae, the Seahorses. In total, the Pipefish family contains four subfamilies, 55 genera, and over 320 species (Kuiter, 2000). At one point the animals in this family were thought to be insects (Rafinesque, 1810; Michael, 1998), but it is now clearly known these animals are actually fish, even if they are strange-looking fish.

All Syngnathids possess an elongated semi-flexible body with armored, bony plates. They do not possess scales. Gill openings are usually reduced to a small round pore, and the head is generally long and tubular. The jaws are fused, resulting in a structure without a hinge to open and close. All fins are soft-rayed, with most species having one dorsal fin, and pectoral fins. Some species may have caudal fins, while yet other species are entirely fin-less. Ventral and second dorsal fins are absent in all Syngnathids. Another factoid worth mentioning about Syngnathids is their reproductive habit: The males are the ones that become pregnant! In all species the male carries the eggs during the incubation period. More on this shortly.

The subfamily Doryrhamphinae, known commonly as Flagtail Pipefish, contains four genera and 22 species. Unlike the vast majority of Syngnathids, the subfamily Doryrhamphinae swims above the substrate, and is never in contact with the substrate (except for Maroubra). Likewise, it does not maintain a grip on sea grasses, gorgonians, or any other steadfast. This subfamily features an abnormally large (for Syngnathids) caudal fin. These Indo-West Pacific specimens all carry the eggs of the young under the trunk of the male (Kuiter, 2000).

Doryrhamphus consists of 11 species, though the taxonomy is incredibly incomplete and lacking. Many localized color forms are present, and most specimens are lumped together as a single species, a result of inconclusive research from preserved specimens. Once further research is put forth, it is likely the number of species will rise (Kuiter, 2000).

Dunkerocampus, much like Doryrhamphus, is one of the few genera of free-swimming pipefish. Like all free-swimming pipefish, Dunkerocampus males keep the eggs in a pouch under the trunk. This pouch does not close, and subsequently the eggs are not covered while the male carries them. Previously known as Acanthognathus, Dunkerocampus has also been regarded as a subgenus of Doryrhamphus, but today maintains generic status and maintains no less than eight species from the Indo-West Pacific.

Though the majority of pipefish that appear in our hobby are from the subfamily Doryrhamphinae, with Doryrhamphus and Dunkerocampus accounting for the largest percentage of the subfamily within the hobby, a large percentage does show up from Syngnathinae, or the subfamily commonly called Pipefish. For the most part, this is a highly unorganized subfamily that is likely to be split into their separate taxon once additional research is put forth. For now, 42 genera are recognized, though only Corythoichthys is likely to be found at your local fish store with any regularity.

The care of Corythoichthys is similar to that of any other pipefish. The main points of consideration would be the temperature that the particular species originated from, as well as the type of bottom cover it preferred. All Corythoichthys are found along the substrate, unlike Doryrhamphus and Dunkerocampus species. Some members prefer muck bottoms, while others prefer rock rubble and algae. The pipefish that prefer to swim along the substrate have a differently designed brood pouch than do their free-swimming cousins. This brood pouch is designed to enclose the eggs, and in these enclosed pouches the embryos are attached to highly vascularized placenta-like tissue, which seals the pouch folds from inside during incubation (Watanabe et al, 1999). It would seem, therefore, that the embryos of the substrate dwelling pipefish are considerably more protected than those of the free-swimming pipefish. Twenty-three species are currently described members of Corythoichthys, with many more un-described members awaiting entrance.

In the Wild

Pipefish, like all Syngnathids, are secretive fish and are highly localized and restricted in their distribution. You are more likely to locate them in bays and lagoons then you would be on the fore-reef. Depths range from 5m to 30m of depth in subtropical regions, usually associating with overhangs or crevices within the rockwork, which supply a place to retreat. This quick retreat is basically their only means of defense. Their bony plates offer little protection against predators that are likely to swallow them whole. Rarely will they leave the comfort and protection of their overhangs or crevices.

Most members of the genus Doryrhamphus have been noted as "cleaner fish" (see To Clean or Not to Clean: Gobiosoma Species for more information on "cleaner fish"). However, unlike typical "cleaners," the pipefish do not setup highly visible "cleaning stations." Doryrhamphus species are noted to clean the cryptic clients, those such as moray eels, groupers, and cardinalfish (Michael, 1998). This makes up a small portion of their diet. The majority of their diet is comprised of the tiny crustaceans that swim near the substrate, though just about any larva that fits into their mouth is consumed. Foods that are not able to fit into their fixed jaws are often "de-gutted," that is, they suck the abdomen out of the food item, and let the skeleton go without further attention.

During feeding, the "where" seems to be unimportant for them, as pipefish will feed from the substrate, or they will also feed on passing-by foods in the water column. The "when" and "how often," however, is extremely important. To begin with, they are diurnal. Therefore, they will only eat during the day. Second, due to the lack of a stomach, and a largely inefficient intestine, pipefish will continue to search for food the entire day.

Adults are always located in pairs, though these pairs are not necessarily maintained monogamous. The pair will greet each other every morning, just minutes prior to sunrise. This greeting consists of the beginning stages of the mating ritual (Gronell, 1984). It is not known what purpose this morning greeting serves, but it has been speculated that it could increase spawning synchrony between the mates, keep the pair bound during non-reproductive periods, or even alert the pair to a missing mate (Michael, 1998).

Reproduction of pipefish is a long process, usually consisting of over two hours of a predictable mating ritual (see below). Once near completion, the female will deposit her eggs into the male's pouch. The number of eggs can vary from 30 -1000 depending on the species and age of the animals participating (Kuiter, 2000), though most species have egg counts numbering closer to 100 - 200. The female will transfer all of the eggs in 4 - 7 seconds (Michael, 1998). The fry are well developed at hatching, but have a short pelagic stage. Due to the advanced adaptation to specific localized conditions within the species of the family Syngnathidae, it is believed dispersal from the pelagic stage is minimal.

The 9 Steps to the Successful Mating Ritual of Pipefishes (Gronell, 1984)

The unusual brooding habits of Syngnathidae have brought upon another interesting sexually characteristic among pipefish: sex-role reversal. Because the male Syngnathids carry the eggs to full term, the males are now in the driver's seat when it comes to choosing which female to breed with. In other words, the females compete for the males. Females are forced to compete with other females to garner the attention of the males. To help the male choose the healthiest female pipefish, females have a couple of ways of displaying health. First, the overall size of the female is important. Berglund et al (1986a) showed larger females produced more numerous and larger eggs which consequently gives way to larger and healthier fry (Ahnesjo, 1992a, b). Secondly, females compete with each other by developing higher degrees of contrast in coloration, often called ornamentation. These colors are not directed towards the male, though the males obviously choose females based on the brighter colors. Instead, the females flash the color ornaments towards competing females. Brighter, more colorful females dance and copulate sooner, copulate more often, and transfer more eggs when compared to the more dully-colored specimens (Gasparini and Teixeira, 1999).

Although pipefish have been described as monogamous in the past, this is simply not true. By definition, monogamous indicates an eternal life partner. Instead, male pipefish form "pair-bonds" which usually last at least one season. It is believed they can remember which female they were most impressed with, and thus continually mate with her. However, some pipefish, notably the females, move beyond this "pair-bond" (Vincent et al, 1994). Females are able to produce an endless supply of hydrated eggs thanks to an ovary unique to pipefish (Begovac and Wallace, 1987; 1988). Therefore, the female is always ready to mate with additional males, should she be able to convince them into mating with her. In addition, females play absolutely no part in the brood care or raising of the fry (Berglund et al, 1986b) once the eggs have been passed to the male, and thus can easily move from one male to the next.

In the Home Aquarium

Provided the needs of the pipefish are met, these fish can live many years within the confines of a home aquarium. Lifespan is currently considered 5 to 10 years in an aquarium. The correct water parameters, tank mates, food options, and tank design are all of importance, and can each lead to success or failure.

Starting with water parameters, like any saltwater fish, the hobbyist should strive for tank conditions as near to natural saltwater conditions (NSW) as possible. Unlike most other fish, the calcium level in the aquarium is important to pipefish. Their bony exoskeleton depends on the calcium to maintain its strength. Calcium levels from 350ppm and up should be sufficient. Remembering most pipefish are subtropical, aquarium temperatures should range from 72 to 80 degrees Fahrenheit.

Fellow tank mates are a paramount consideration in a pipefish tank, and often is the difference between success and failure. As a whole, pipefish will not pester any fish. They are, for the most part, oblivious to anything else in the tank that does not fit into their tiny mouths. This general rule can be extended from fish to corals, and mobile invertebrates. However, in that same regard, if it can fit into their mouth, it likely will be consumed. This would include all micro fauna in the aquarium, as well as fish and shrimp fry. Despite the low-key personality of pipefish, their tank mates often pester them. All but the smallest, most peaceful fish should be eliminated from a pipefish aquarium. Suitable tank mates would include most gobies, dragonettes, other seahorses, and shrimpfish. Any fast-swimming fish is likely to agitate the pipefish and keep them in hiding. Fish that are aggressive feeders are likely to do the same. Any fish that tends to be "curious" is likely to annoy the pipefish. This would include wrasses, blennies, and dwarf angels. Naturally, predatory fish often times make a quick snack out of pipefish. Large predatory mobile invertebrates such as certain starfish species, lobsters, and hermit crabs should be avoided, as well as any potentially strong-venom corals such as any LPS corals and anemones.

Compatibility chart for Pipefish:

Fish	Will Co-Exist	May Co-Exist	Will Not Co-Exist	Notes
Angels, Dwarf		X		Will likely pester until death ensues.
Angels, Large		X		Large, fast fish are best kept in separate tanks.
Anthias		X		Aggressive feeders will make it difficult to get prepared live foods to pipefish.
Assessors	X			Excellent choice.
Basses			X	Will likely pester until death ensues.
Batfish		X		Large, fast fish are best kept in separate tanks.
Blennies		X		Will likely pester until death ensues, though some smaller members would be good choices.
Boxfishes			X	Will likely pester until death ensues.
Butterflies		X		Large, fast fish are best kept in separate tanks.
Cardinals	X			Excellent choice.
Catfish			X	Will likely pester until death ensues.
Comet	X			Excellent choice.
Cowfish			X	Will likely pester until death ensues.
Damsels			X	Will likely pester until death ensues.
Dottybacks			X	Some dottybacks require dedicated aquariums.
Dragonets	X			Excellent choice.
Drums			X	Will consume pipefish.
Eels		X		Some pipefish are known to "clean" members of this family, though it is best to avoid them sharing the same aquarium.
Filefish			X	Large, fast fish are best kept in separate tanks.
Frogfish			X	Will consume pipefish.
Goatfish			X	Will consume pipefish.
Gobies	X			Excellent choice.
Grammas		X		Avoiding grammas would be playing it safe.
Groupers		X		Some pipefish are known to "clean" members of this family, though it is best to avoid them sharing the same aquarium.
Hamlets			X	Will likely pester until death ensues.
Hawkfish			X	Will likely pester until death ensues.
Jawfish	X			Excellent choice.
Lionfish		X		Some pipefish are known to "clean" members of this family, though it is best to avoid them sharing the same aquarium.
Parrotfish			X	Will consume pipefish.
Pineapple Fish		X		Should co-exist peacefully.
Pipefish	X			Excellent choice.
Puffers			X	Will consume pipefish.
Rabbitfish		X		Large, fast fish are best kept in separate tanks.
Sand Perches			X	Will consume pipefish.
Scorpionfish			X	Will consume pipefish.
Seahorses	X			Excellent choice.
Snappers			X	Will consume pipefish.
Soapfishes			X	Will consume pipefish.
Soldierfish			X	Will consume pipefish.
Spinecheeks		X		Large, fast fish are best kept in separate tanks.
Squirrelfish			X	Will consume pipefish.
Surgeonfish		X		Large, fast fish are best kept in separate tanks.
Sweetlips			X	Will consume pipefish.
Tilefish		X		May annoy pipefish.
Toadfish			X	Will consume pipefish.
Triggerfish			X	Will consume pipefish.
Waspfish			X	Will consume pipefish.
Wrasses		X		Most wrasses will pester pipefish.

Note: While many of the fish listed are good tank mates for Pipefish, you should research each fish individually before adding it to your aquarium. Some of the fish mentioned are better left in the ocean, or for advanced aquarists.

Ensuring the proper size food, and that enough of it reaches the pipefish is another major concern. Thankfully, hobbyists are becoming more informed on this important detail, and as such many ill-prepared hobbyists have rightfully avoided this family. Food items would include any of the naturally growing microfaunal animals found in our aquariums, including copepods, amphipods, and mysid shrimp. Therefore, the hobbyist would be smart to encourage the natural growths of these animals. A dedicated refugium for a pipefish tank is a wise idea, or a large refugium can make a perfect pipefish aquarium itself. Pipefish are regularly found searching algae beds for food in the wild. These algae beds encourage the colonization by microfauna, and therefore colonies of macro algae like various Caulerpa species are important additions into any pipefish aquarium. When additional foods are required, the best substitutes are live foods. Hatching brine shrimp, mosquito larvae, or even daphnia at home can prove to be a successful means of food supplementation, or a welcome treat for pipefish that normally do not need an additional food source. In many situations, pipefish are not willing to accept frozen/thawed prepared foods. In time some individuals may begin to accept prepared adult brine shrimp, Mysis shrimp, or any number of commercially available foods. Most specimens, however, will never accept prepared foods. Be prepared to supply live foods for the lifespan of your pipefish should you consider obtaining these fish. Most importantly, due to the lack of stomach and inefficient intestines, the hobbyist must be prepared to provide large amounts of these foods. If you are counting on the bulk of the pipefish diet to be supplied by yourself, consider that three feedings per day is the minimum necessary.

Lastly, tank design is significant. This aspect isn't nearly as important as the three previously discussed requirements, but nonetheless, these minimal requirements should not be considered voluntary. An active, healthy sandbed should be required. If possible, sand from several different sources should be acquired to ensure as much diversity as possible. This sandbed will supply a large percentage of the naturally occurring foods for the pipefish. Likewise, good quantities of porous live rock are desirable. As mentioned above, various colonies of algae are also prime locations of microfaunal colonization, and thus should be considered mandatory in the pipefish aquarium. Caves and overhangs are a wise idea, both as a comfort factor for your pipefish, and for the viewing pleasure of the hobbyists. In most cases, you can design your rockwork to feature overhangs in prime locations for your viewing, and your Doryrhamphus sp. will immediately take to this overhang. Without these overhangs, the pipefish is likely to take up residence somewhere buried behind the rockwork, much to the disappointment of all intending on viewing these fish.

Reproduction In The Home Aquarium

Spawning and rearing of pipefish in the home aquarium is entirely possible, provided the hobbyist wishes to give the extra effort. Once the pair has successfully mated and the males begin to carry the eggs, hatching is merely days to weeks away. The hatch time varies depending on species, as well as water temperature, where a 1 degree Celsius temperature change could mean an increase (or theoretically decrease) in the brooding period by as much as two days (Michael, 1998). Newly hatched pipefish are free-swimming and fully developed; though a short pelagic stage does occur. Color pigmentation usually takes place once the juveniles begin to settle to the substrate. Rotifers are required as first-foods for the pipefish fry, and will be required until the fry are large enough to consume newly hatched brine shrimp.

Meet the Species

Most of the Doryrhamphus species are fairly similar, with only slight color differences of the caudal fin and geographical locations setting them apart. Therefore, getting an exact identification on this genus is extremely difficult, if not impossible. Following the chart below will give you your best chance at proper identification.

The final member of Doryrhamphus is D. janssi, or commonly called Janssi's or Jan's Pipefish. Whereas most other Doryrhamphus barely reach three inches in length, D. janssi will reach over five inches in total length. In the wild Jan's is reported to be an exclusive cleaner for Cheilodipterus (Cardinalfish) and Neopomacentrus (Damsel) species (Michael, 1998). It has perhaps the largest distribution of all pipefish, covering most of the West Pacific from 3 to 120 feet of depth. Like D. melanpleura, it spends much of its lifetime swimming upside-down.

Several members of Dunkerocampus have become regular imports for the marine fish hobby; D. dactyliophorus is one of them. It is a west Pacific native that spends a majority of its time in shallow water where it spends a large portion of the day "cleaning" moray eels. They readily make the transition to home aquariums provided the above listed criteria are met. Juveniles will stay in small groups, but adults are always found in pairs.

The other popular Dunkerocampus that regularly shows up in the trade is the Yellow Banded Pipefish, or D. pessuliferus. It is often confused with D. multiannulatus due to similar coloration. This species is most often located near deep mud flats and drop-offs searching for food or even a "client" fish. It is not shy in the wild or in the home aquarium - possibly the most outgoing Syngnathidae.

A Special Treat

Most of us will never be lucky enough to witness one these beauties outside the pages of books or Internet websites. The majority of people that get to see these fish in person usually are located within a public aquarium. Fewer still will have an opportunity to dive with these gems. Almost no one will have the chance to attempt to maintain one in a home aquarium.

Although referred to commonly as Ghost Pipefish, these majestic animals are not from the family Syngnathidae. They are close cousins, however, and are presently placed in the family Solenostomidae, which has only one genus, Solenostomus, and roughly six species (see below). A few characteristics create the need for a family separate from Syngnathidae. First, Solenostomus species have ventral fins, a second dorsal fin, and all fins are well developed. Another important difference is the male does not brood-care for the eggs, the female does. Members of this family are well spread out geographically, most likely due to the extended pelagic stage (when compared to Syngnathidae). However, it appears they have a relatively short lifespan. Should you come across one of these rarities of the hobby, you can be assured that care is similar to that of the members of the family Syngnathidae.

Solenostomus paradoxus, also called the Ornate Pipefish, is highly variable in coloration and is widespread throughout the tropical Indo-West Pacific. They enjoy brisk currents over open sand beds littered with gorgonians. At four inches in length, it is a moderately sized Ghost Pipefish.

Solenostomus cyanopterus, or the Robust Pipefish, can be located throughout the western Pacific and also throughout the Indian Ocean. Again, color is variable, but not necessarily the rainbow of colors as seen in S. paradoxus. This fish associates with sea grasses and algae in back bays and protected fringing reefs. Like other members of Solenostomus, the Robust Pipefish generally hangs vertically in the water column, with its face looking towards the substrate. As the name implies, this member is the largest Ghost Pipefish.

Solenostomus paegnius, or as some may call it, the Rough-Snout Pipefish, is another widespread tropical Indo-West Pacific native. This species is closely related to S. cyanopterus, except the caudal peduncle is considerably shorter and, as the common name implies, has many hairy or bushy appendages growing from its snout. Like all Ghost Pipefish, this member settles from the pelagic stage at nearly full adult size, and is a fully functional reproductive adult.

Above: A pair of Solenostomus paradoxus. The female, seen here on the right, is considerably larger than males. Below: Solenostomus paradoxus is nearly transparent during the post-pelagic stage, but eventually takes on a large assortment of colors including red, black, yellow, blue, orange, and various shades therein. Photos courtesy of Linda Cline of Dancing Fish.

Conclusion

Sometimes hobbyists begin searching for a new challenge, or a new family of fish featuring interesting behaviors. When the desire to take the hobby to the next level strikes, pipefish are there. Undoubtedly, pipefish are among the more exotic fish that show into our local fish stores.

Care of pipefish is rather simple. When researched and assembled correctly, a pipefish aquarium can be remarkably fulfilling with little additional effort from the hobbyist. Much like the dragonette fish family, pipefish truly are a fish that do not need any additional labor on the part of the hobbyist to thrive. A well planned and thought out aquarium most often affords the pipefish with everything they need. When designed poorly, a pipefish aquarium can become a daily chore that quickly tires the fish keeper, or worse yet, leads to the untimely death of the pipefish.

Next time you consider adding fish into a large refugium, or consider setting up a species designed aquarium, consider the choice of a pair of pipefish.

References:

Ahnesjo, I. 1992a. Consequences of male brood care; weight and number of newborn in a sex-role reversed pipefish. Funct. Ecol. 6:274-281.

Ahnesjo, I. 1992b. Fewer newborn result in superior juveniles in the paternally brooding Syngnathus typhle. J. Fish Biol. 41B:53-63.

Begovac, P. C. and Wallace, R. A.,1987, Ovary of the pipefish Syngnathus scovelli. Jour. Morph., 193: 117-133.

Begovac, P. C. and Wallace, R. A.,1988, Stages of oocyte development in the pipefish Syngnathus scovelli. Jour. Morph. 197: 353-369.

Berglund, A., G. Rosenqvist, and I. Svensson. 1986a. Reversed sex roles and parental energy investment in zygotes of two pipefish (Syngnathidae) species. Mar. Ecol. (Progr. Ser.) 29:209-215.

Berglund, A., Rosenqvist, G., and Svensson, I. 1986b. Mate choice, fecundity and sexual dimorphism in two pipefish species (Synganthidae). Behav. Ecol. Sociobiol. 19:301-307.

Berglund, A., Rosenqvist, G. and Bernet, P. 1997. Ornamentation predicts reproductive success in female pipefish. Behav. Ecol. Sociobiol. 40:140-145.

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Berglund, A. and Rosenqvist, G. 2001. Male pipefish prefer dominant over attractive females. Behav. Ecol. 12:402-406.

Berglund, A. and Rosenqvist, G. 2001. Male pipefish prefer ornamented females. Anim. Behav. 61:345-350.

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Dawson, C.E., 1985 Indo-Pacific pipefishes (Red Sea to the Americas). The Gulf Coast Research Laboratory Ocean Springs, Mississippi, USA.

Eschmeyer, W.N., 1990 Catalog of the genera of recent fishes. California Academy of Sciences, San Francisco, USA. 697 p.

Gasparini, J.L. and Teixeira, R. L. 1999. Reproductive aspects of the gulf pipefish, Syngnathus scoveli (Teleostei: Syngnathidae), from southeastern Brazil. Rev. Brasil. Biol.

Gronell, A. M. 1984. Courtship, spawning, and social organization of the pipefish, Corythoichthys intestinalis (Pisces: Syngnathidae) with notes on congeneric species. Z. Tierpsychol. 65:1-24.

Jones, A.G., et al. 2000. The Bateman gradient and the cause of sexual selection in a sex-role-reversed pipefish. Proc. Roy. Soc. B. 267:677-680.

Jones, A.G., et al. 2000. Mate quality influences multiple maternity in the sex-role-reversed pipefish Syngnathus typhle. Oikos 90:321-326.

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Lieske, E. and R. Myers, 1994 Collins Pocket Guide. Coral reef fishes. Indo-Pacific & Caribbean including the Red Sea. Haper Collins Publishers. 400 p.

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Sandvik, M., et al. 2000. Male and female mate choice affects offspring quality in a sex role reversed pipefish. Proc. Roy. Soc. B. 267:2151-2155.

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Watanabe, S., et al. 1999. Immunocytochemical detection of mitochondria-rich cells in the brood pouch epithelium of the pipefish, Syngnathus schlegeli : structural comparison with mitochondria-rich cells in the gills and larval epidermis. Cell Tissue Res 295 (1999) 1, 141-149