seahorses keep floating

Dear Chris:

I’m very sorry to hear that your seahorses are having a problem. They are suffering from positive buoyancy, which can result from a number of different problems such as hyperinflation of the gas bladder or certain forms of Gas Bubble Syndrome (GBS). Are all the seahorses in the aquarium affected? Both the males and the females? Are the females also floating and having difficulty swimming and maintaining their normal equilibrium, Chris? How tall is your seahorse tank? Do any of the seahorses have blisterlike bubbles on their tails or elsewhere on their bodies? Are there abdomens or pouches swollen and distended?

It’s very unusual for all of the seahorses to be afflicted with such a problem at the same time, which makes me suspect that there may be something wrong with the environmental conditions in your aquarium — perhaps something that is causing gas supersaturation of the water and leading to problems with GBS. Check your equipment, Chris — see if one of your water pumps has developed a leak that is causing it to entrain air and inject air bubbles into the water under pressure at depth. Have you added any new equipment to the aquarium recently? A new protein skimmer or a new water pump or filter? If possible, check the dissolved oxygen levels in the aquarium, along with your other water quality parameters (especially the pH).

There are some simple measures and precautions you can take to help prevent gas supersaturation and problems with GBS in the aquarium, which are discussed below, Chris.

Preventing Gas Bubble Syndrome

Since GBS is caused by physical factors in the seahorse setup, when the affliction crops up, it’s a red flag that indicates that there’s something amiss with the conditions in your tank. With that in mind, I would like to quickly review some of the preventative measures aquarists can take to minimize problems with Gas Bubble Syndrome:

(1) Aquarium options (Giwojna, Jan. 2004):

Taller is better. When shopping for a seahorse setup, opt for the tall or high model of the largest aquarium you can reasonable afford and maintain. If the tank is too short, male seahorses may not be able to get enough pumping action in as they ascend and descend during courtship displays and mating (the copulatory rise) to flush out their pouches and cleanse them properly (Cozzi-Schmarr, 2003). This can contribute to bloated pouch, a type of pouch emphysema.

As a rule, your seahorses require a minimum of three times their height (total length) in vertical swimming space in order to mate comfortably and help avoid this sort of pouch gas problem.

Other forms of GBS are also believed to be depth related, but the aquarium must be greater than 30 inches deep to provide any significant protection against them, which is not feasible for most hobbyists (Giwojna, Jan. 2004). A depth of at least 3 feet is known to protect the Hawaiian seahorse (Hippocampus fisheri) against GBD (Karen Brittain, pers. com.).

If you’ve had a problem with GBS in the past, look for a tank at least 20-30 inches tall, reduce your water temp to 70-degrees F, and avoid overly tall hitching posts that reach near the water’s surface (Cozzi-Schmarr, 2003). You want to encourage the seahorses to hang out near the bottom in order to take advantage of every inch of depth the aquarium can provide.

(2) Filtration options (Giwojna, Jan. 2004):

Gas supersaturation of the water can occur whenever the dissolved gas pressure in the water is greater than the atmospheric pressure. When that happens, the dissolved gases in the seahorse’s tissues are no longer in equilibrium with the surrounding aquarium water, causing gas to move into the area with lower partial gas pressure — the tissues and blood of the seahorse – and come out of solution, forming gas emboli! Providing proper filtration, circulation, and aeration can prevent this.

Add:
Trickle filter (acts as a de-embolizing tower or degassing column).
External filter that returns water as a "water fall."
A spray bar return positioned just above the surface.
Sump with strong aeration.
Overflow drains, as opposed to siphon/suction tubes.
Surface agitation to facilitate efficient gas exchange.
Increased circulation and water movement.
Extra airstone(s) just below the surface of the water.

Having a trickle filter, water "falling" into the tank as it’s returned, or strong aeration in the tank or the sump will help off-gas any supersaturated dissolved gases (Giwojna, Jan. 2004). This will also help off-gas a build up of CO2 and the associated pH drop that some tanks experience when the lights go off (Giwojna, Jan. 2004). The off gassing or degassing takes place only at the very air/water interface, so you want to spread the water into very thin sheets and let it be in contact with the atmosphere for an extended period (Robin Weber, pers. com.). That is precisely what a degassing column does by trickling water over solid media open to the atmosphere, and if properly maintained and operated, a wet/dry trickle filter can perform the same function (Jorge A. Gomezjurado, pers. com.). For best results, the outflow from a trickle filter should go into a baffled chamber that will allow bubbles to dissipate before they enter pumps or plumbing restrictions (J. Charles Delbeek, pers. com.).

Avoid:
Airstones, air lifts, bubble wands, etc., if submerged deeper than 18 inches.
Leaky pumps.
Subsurface entry of the inflowing or recirculating water.

On small, closed-system aquariums, supersaturation is often due to the entraining of air on the intake side of a leaky pump, which then chops the air into fine microbubbles and injects it into the water (Cripe, Kowalski and Phipps, 1999). Water and air are thus mixed under high pressure and forced into the water column, which can result in gas supersaturation. An air leak in inflowing or recirculating water that enters the tank below the surface can cause the same thing (Cripe, Kowalski and Phipps, 1999). Allowing the water to splash before it enters the tank is a simple way to prevent this from happening. The splashing helps the water to expel excess gas and reach equilibrium with the ambient air pressure (Giwojna, Jan. 2004).

Likewise, airstones, air lifts, bubble wands and the like can cause problems if they are too deep because they will cause gas to dissolve in water to match the ambient pressure (the current atmospheric pressure) PLUS the pressure of the water column above the stone. If they are immersed at a depth greater than 18 inches, the pressure of the water column above them may be sufficient to cause gas supersaturation of the water, especially when there is little atmosphere/water interface (Colt & Westers, 1982). For example, Robin Weber found that airstone submerged in reservoirs 3 feet deep produced excessive gas supersaturation at the Monterey Bay Aquarium. The airstones produced supersaturation at a level of about 104%, and the only cases of GBS she has ever observed at the aquarium occurred in the most supersaturated exhibits. So keep your airstones shallow!

(3) Eliminate stress (Giwojna, Jan. 2004):

Avoid overcrowding.
Avoid aggressive tankmates.
Install a titanium grounding probe to eliminate stray voltage.
Avoid exposing the seahorse tank to excessive noise or heavy foot traffic.
Use a cork or Styrofoam aquarium pad beneath the tank to deaden vibrations.

Stress has been linked to GBS in seahorses via the following mechanism: chronic or prolonged stress causes changes in the seahorse’s blood chemistry (acidosis), which in turn affects the oxygen-carrying capacity of certain types of hemoglobin, and the reduced oxygen-carrying capacity of hemoglobin can then causes embolisms to form in the blood.
The excess of protons (H+) under acid conditions also causes carbonic anhydrase to shift to producing CO2 from carbonic acid in the bloodstream, and the CO2 that results can likewise lead to gas embolisms under certain circumstances (Giwojna, Jan. 2004).
Mic Payne is one of the professionals who feel GBS is most likely a stress-related affliction. He believes it is often a result of chronic stress due to antagonistic behavior by overaggressive males, particularly if they are overcrowded (Payne, pers. com.). Exposing our seahorses to any type of stress may leave them predisposed to GBS (and vulnerable to many other diseases as well). Reduce the stress levels on our seahorses and we reduce the incidence of GBS accordingly (Giwojna, Jan. 2004).

(4) Maintain optimum water quality (Giwojna, Jan. 2004):

Don’t overfeed and remove leftovers promptly.
Employ an efficient cleanup crew.
Practice sound aquarium management and maintenance.
Monitor the aquarium parameters regularly.
Maintain total alkalinity and keep your pH between 8.1-8.4
Maintain a strict schedule for routine water changes.

When he was experimenting with possible treatments for GBS, Paul Groves (Head Aquarist at Underwater World in Perth, Australia, at the time) was able to produce all the different forms of GBS in a control group of Hippocampus breviceps simply by exposing them to a dirty, bacteria-laden substrate. His seahorse setup was far better than any hobbyist could hope for — an open system with 100% flow through from the ocean and a live sand base, yet all the seahorses in the tank eventually developed GBS (Groves, pers. com.). Males with chronic pouch gas were the first to appear, followed by specimens with internal GBS, and finally subcutaneous gas bubbles appeared on the tails and snouts of the others Groves, pers. com.). The weakness of Paul’s setup was poor circulation, and for experimental purposes, he deliberately allowed fecal matter and uneaten nauplii to build up on the bed of live sand. (Groves found that antibiotics were totally ineffective in treating GBS, but he eventually cured 10 of the 12 affected seahorses using decompression at a depth of 4 meters.)

It is not clear whether stress from the dirty conditions or exposure to such a high density of bacteria triggered the problem in this case, but the lesson is loud and clear all the same — it pays to keep those aquariums clean (Giwojna, Jan. 2004)! If we keep our seahorses setups clean, we will keep our problems with GBS to a minimum (Giwojna, Jan. 2004).

Maintaining the proper pH is especially important for seahorses, since low pH in the aquarium can result in general metabolic acidosis, leading to gas embolisms via the same mechanisms as stress-induced GBS (Giwojna, Jan. 2004).

(5) Water changing precautions (Giwojna, Jan. 2004):

It’s an excellent idea to use Reverse Osmosis (RO) or Deionized (DI) or RO/DI water for your changes because it’s much more pure than tap water. However, water purified by such methods is very soft and must be buffered before it’s used so it won’t drop the pH in your aquarium when it’s added (Giwojna, Jan. 2004).

When mixing saltwater for your marine aquarium, it’s important to fill your container with all the water you will need BEFORE adding the salt mix. In other words, if you are mixing up 5 gallons of new saltwater, fill the mixing container with 5 gallons of water and then add the salt. If you do it the other way around — dump the salt mix in the container and then start filling it with water, the water can become saturated with salt to the point that the calcium precipitates out. This calcium precipitation will turn the water milky and can also lower the pH to dangerous levels (Giwojna, Jan. 2004).

Water changes can also be a problem because of the supersaturation of gases in tap water. Tap water distribution systems are maintained under pressure at all times, both to insure adequate flow and to prevent polluted water from outside the pipes from entering in at leaks. Any additional gas introduced into these pipes (from a leaky manifold, for example) will be dissolved at these higher partial pressures, and will often be supersaturated when it emerges from the tap (Giwojna, Jan. 2004). Also, gases are more soluble in cold water than warm, so when gas-saturated cold water emerges from the tap and warms up in an aquarium, or is warmed up and preadjusted to aquarium temps prior to making a water change, the water can become supersaturated (Giwojna, Jan. 2004). This must be avoided at all costs because gas supersaturation is one of the factors that can contribute to Gas Bubble Disease in seahorses and other fish.

To prevent this, tap water should be allowed to sit for several days beforehand or gentle aeration can be used to remove gas supersaturation before a water change (just make sure your airstones are not be submerged greater than 18 inches while you’re aerating your freshly mixed water; (Giwojna, Jan. 2004)). Some brands of artificial sea salt also produce low levels of ammonia immediately after mixing with water, and aging or aerating the newly mixed water as described above will dissipate this residual ammonia.

Most of the above is mentioned for future reference — I realize there aren’t many modifications you can make after the fact, once your system is already up and running (Giwojna, Jan. 2004). But there are a few things you can try with your existing system that should help.

First of all, whenever you find yourself dealing with an environmental disease such as GBS, a water change is an excellent place to start. At the first sign of GBS, I suggest you combine a 25%-50% water change with a thorough aquarium clean up (Giwojna, Jan. 2004).

Secondly, consider adding an ordinary airstone to your tank, anchored just beneath the surface of the water. That will add surface agitation, extra aeration, and better gas exchange at the air/water interface (Giwojna, Jan. 2004). Unless you’re quite certain your system already has plenty of water movement, it is also advisable to add a small powerhead for extra circulation (Giwojna, Jan. 2004). Seahorses can handle more water movement than most folks realize, and you can always turn it off during feedings. Just screen off the intake for the powerhead as a precaution so it can’t accidentally suck up a curious seahorse (Giwojna, Jan. 2004).

Finally, use shorter hitching posts and holdfasts that will confine your seahorses to the bottom half of the aquarium and reduce the water temperature. Shorter hitching posts will get the maximum benefit from whatever depth your tank can provide, and lowering the water temperature allows the water to hold more dissolved gases, which can help avoid any tendency toward supersaturation (Cozzi-Schmarr, 2003).

Those simple measures may make a big difference. Just maintain good water quality, add a shallow airstone and perhaps an extra power head to provide better water movement and gas exchange, and keep things cool and you can reduce your risk of GBS considerably (Giwojna, Jan. 2004).

Please take a quick look at the items mentioned above and see if any of them may apply in your case, Chris. If so, address those issues as discussed above.

Secondly, in order to resolve a positive buoyancy that is causing your seahorses to float, I would recommend treating the affected seahorses with Diamox (the tablet form of acetazolamide). Unfortunately, obtaining Diamox can often be a Catch-22 situation for hobbyists. It is a prescription drug often used for treating glaucoma, hydrocephaly, epilepsy, congestive heart failure, and altitude sickness in humans so you have to get it from your Vet or perhaps your family doctor. Unfortunately, Veterinarians are often unfamiliar with Diamox — it’s very much a people med and unless you find a Vet that works with fish regularly, he or she will probably never have heard of gas bubble disease or treating it with carbonic anhydrase inhibitors. Many pet owners are on very good terms with their Vets, who are accustomed to prescribing medications for animals, so it’s often best to approach your Vet first about obtaining Diamox despite the fact they may never have heard of it until you brought it to their attention. Your family doctor, of course, will be familiar with such medications and have Diamox on hand but it can sometimes be difficult to get your MD to jump that final hurdle and prescribe it for a pet. Either way, it can be tough to get the medication you need under these circumstances.

If not — if neither your Vet or family physician will prescribe Diamox — then there are places you can order Diamox online without a prescription, but save that for a last resort. (You can’t always be certain of the quality of the medications you receive from such sources; in some cases, you even need to be concerned about counterfeit drugs, although Diamox certainly shouldn’t fall into that category.) The medications will take a week or two to arrive, which is troublesome when your seahorse is ailing and needs help ASAP. And, as you know, customs officials can confiscate such shipments.

If you ultimately need to go that route, Chris, the following source is the one most seahorse keepers have found works best:

Click here: Inhouse Drugstore Diamox – online information
http://www.inhousedrugstore.com/neurological/diamox.html

They offer 100 tablets of Diamox (250 mg) for around $20 US, but they ship from Canada by mail, which usually takes a little under two weeks for delivery.

If the affected seahorses are still eating, Chris, then I suggest you try administering the Diamox orally via injected shrimp. I have found that the Diamox is often more effective when it’s ingested and administering the medication orally allows you to treat the seahorse in the main tank where he’s most comfortable and relaxed. Here are the directions for this method of treatment, if you think it might be feasible in your case, Chris

If you can obtain a small syringe with a fine needle, the acetazolamide solution can simply be injected into feeder shrimp or even frozen Mysis. Mic Payne (Seahorse Sanctuary) used this method of administering Diamox successfully when he had recurring problems with GBD due to maintaining a population of Hippocampus subelongatus in shallow tanks only 16-inches (40 cm) deep:

"Seahorses maintained in this system are susceptible to gas bubble disease. Specimens with bubbles around the eyes or under the epidermis of the tail are readily treated with acetazolamide (Diamox tablets 250 mg). Mix a very small amount of crushed tablet with water and inject it into several glass shrimp that are then frozen. These are then fed to the target animal at the rate of two per day for four days. Bubbles disappear on the second day."

Volcano shrimp or red feeder shrimp from Ocean Rider (iron horse feed) work great for this. If a fine enough needle is used, they will survive a short while after being injected — long enough for their twitching and leg movements to attract the interest of the seahorse and trigger a feeding response.

Leslie Leddo has cured seahorses with tail bubbles and pouch gas using this technique. She found that a 1/2 cc insulin syringe with a 26-gauge needle was ideal for injecting frozen Mysis or live red feeder shrimp. They plump up when injected and ~1/2 cc is about the most of the solution they can hold. There bodies will actually swell slightly as they are slowly injected and excess solution may start to leak out. The 26-gauge needle is fine enough that it does not kill the feeder shrimp outright; they survive long enough for the kicking of their legs and twitching to assure that they will be eaten. So if your Vet or family doctor will prescribe the Diamox for treating your seahorse, ask them also to provide a 1/2 cc insulin syringe with a 26-gauge needle.

If you are using 250-mg tablets, Leslie found that 1/8 of a tablet provides enough Diamox for several days’ worth of injections. In other words, 1/8 of a 250-mg Diamox tablet provides enough of the medication to inject two shrimp daily for about 5 days. So each day, I would take 1/8 of a tablet and shave off approximately 20%-25% of it to make the Diamox solution for that day’s injections. (NOTE: if you are using 125-mg Diamox tablets, adjust your dosage accordingly — that is, start with 1/4 of a tablet and then shave off 20%-25% of it to make the Diamox solution.) Then crush the Diamox you have shaved off and to a very fine powder and dissolve it in a very small quantity of water.

Use the result solution to inject two of the live feeder shrimp and feed them to the affected seahorse immediately after injecting them. You don’t want the healthy seahorses to ingest the medicated shrimp, so feed them to Apollo while he is isolated in his fishnet pen just as you have been doing.

Diamox doesn’t dissolve especially well in water; there’s always a residue of undissolved material left behind. Try to avoid this residue when you draw up the medicated solution in your syringe, the particles can sometimes clog up the fine bore needle when you are trying to inject the shrimp.

Each day you will have to prepare fresh Diamox solution to inject the shrimp for that day’s treatment, so just repeat the steps above each day. He should show improvement rapidly, with 2-3 days. If not, after you have fed him injected shrimp for 3 straight days, give him a break from the Diamox for a few days and try again. (Diamox can suppress the appepitite, so feed him unmedicated/uninjected shrimp for a few days to keep him eating and help restore his appetite.) Then feed him Diamox-injected shrimp again at the rate of 2 per day for a total of 3 more days, but this time increase the dosage of Diamox slightly (shave off a bit more of the tablet each day when you mix the new Diamox solution).

Depending on how severe the seahorses’ problems with positive buoyancy are, you may need to handfeed the medicated shrimp to the seahorse. If you can place it right up to their mouths, or even directly in their jaws, that may trigger their feeding instinct and hopefully they’ll slurp it right up. If not — if there positive buoyancy is so severe they cannot perch and feed normally on their own, and they refuses to accept handfeeding — then you have to administer the Diamox in a hospital tank as a series of baths instead. Here is how to proceed:

Acetazolamide (brand name Diamox) Baths

The acetazolamide/Diamox treatments are extremely effective in the treatment of external gas bubble disease and GBS-induced Popeye, and are helpful in treating internal GBS and hyperinflation of the swim bladder as well, especially when the affected seahorse has stopped eating. In such cases a series of acetazolamide baths is used to administer the medication (Warland, 2002).

The baths should be administered in a hospital ward or quarantine tank. Acetazolamide does not appear to adversely affect biofiltration, but it should not be used in the main tank because it could be harmful to inhibit the enzymatic activity of healthy fishes. Treatments involving acetazolamide tablets are still fairly new to the hobby and the most effective dosages and methods for administering the medication are still in the process of being worked out and adjusted, largely by trail and error.

The appropriate amount of the medication to use varies with the size of the seahorse. Also, please note that the dosages given for the acetazolamide baths are correct for a treatment tank containing 8 gallons (30 liters) of saltwater. If you are using a smaller hospital tank, be sure to scale down the dosage to suit the smaller volume of water you are dealing with.

Using the tablet form of acetazolamide (250 mg), crush the required amount to a very fine powder and dissolve it thoroughly in a cup or two of saltwater. There will usually be a slight residue that will not dissolve in saltwater at the normal alkaline pH (8.0-8.4) of seawater (Warland, 2002). That’s perfectly normal. Just add the solution to your isolation tank, minus the residue, of course, at the recommended dosage:

RECOMMENDED DOSAGE

Type of Seahorse _____Size of Seahorse ____Acetazolamide (250-mg)
Mini……………………….up to 3 inches……………1/16 tablet per bath
Small species…………. 3 to 5 inches…………….1/8 tablet per bath
Medium species………..5 to 8 inches…………….1/4 tablet per bath
Large species……………> 8 inches……………….1/2 tablet per bath

As you can see, the usual starting dosage for a seahorse size of your 8 inchers is 1/4 of a 250 mg tablet per 8 gallons of water, but treatments with Diamox have since become much more refined, and most people now find that a considerably larger starting dose is more effective in relieving gas bubble disease. For example, most people now recommend one full 250 mg tablet of Diamox for 8 gallons when bathing a seahorse the size of yours, and that’s the dosage I suggest you use in this case, Chris.

Place the affected seahorse in the treatment tank as soon as first dose of medication has been added. After 24 hours, perform a 100% water change in the hospital tank using premixed water that you’ve carefully aerated and adjusted to be same temperature, pH and salinity. Add a second dose of newly mixed acetazolamide and reintroduce the ailing seahorse to the treatment tank. After a further 24 hours, do another 100% water change and repeat the entire procedure until a total of three treatments have been given. About 24 hours after the third and final dose of acetazolamide has been added to the newly changed saltwater, the medication will have lost its effectiveness and the patient can be returned directly to the main seahorse tank to speed its recovery along.

One of the side affects of acetazolamide baths is loss of appetite. Try to keep the affected seahorses eating by applying them with their favorite live foods during and after treatment, until they have fully recovered.

This 3-day regimen of baths is extremely effective in curing external GBS. They also work fairly well in clearing up Popeye. (Exopthalmia can be result from several different causes, and acetazolamide is only effective when GBS is the cause). Internal GBS is generally more difficult to cure, particularly if the seahorse has stopped eating and the acetazolamide cannot be administered orally. I believe this is because internal GBS is difficult to diagnosis until it is well advanced and emboli have already done serious organ damage.

In stubborn cases, the regimen of acetazolamide baths may have to be repeated a second time. Don’t hesitate to increase the dosage if necessary to clear up the symptoms.

If you cannot obtain Diamox, Chris, you can often also resolve GBS and buoyancy problems by pressurizing the seahorses in a home a decompression chamber, as discussed below. The recompression-decompression cure is a great option for treating Gas Bubble Syndrome (GBD) for hobbyists who are having trouble obtaining Diamox for one reason or another. Anyone can set up a simple homemade decompression chamber and be treating their seahorse as soon as they can mix up a new batch of saltwater.

The Recompression Cure for Gas Bubble Syndrome

Recompression simply involves placing the affected seahorses in a flow-through cage or enclosure and immersing them for a period of days at a depth with sufficient water pressure to cause the emboli to dissolve. The increased hydrostatic pressure causes the gas bubbles that have formed within the tissue and blood of the seahorse to go back into solution where they can be resorbed, relieving the problem. (This is why a decompression chamber is used to treat divers for the "bends," caused by nitrogen gas embolisms within the diver’s tissue and blood.) Afterwards, the seahorses are slowly raised back to normal depth/pressure over a period of hours, allowing the total partial pressures of the dissolved gases in the water and the seahorses’ bloodstream to equalize on the way up.

At present, there is no consensus among the professional aquarists who use this method regarding the exact depth and length of immersion needed to effect a cure. I’ve encountered decompression times ranging from 2 days to 10 days and depths ranging from 10 feet in large aquaria (Paul Groves, pers. com.) to over 35 feet at the bottom of the ocean (Bill Stockly, pers. com.), all of which worked equally well. Interestingly, the shortest immersion time was used successfully at one of the shallowest depths (4 meters) and cured seahorses afflicted with all the different forms of GBS (Paul Groves, pers. com.).

While the exact treatment protocol that will produce the best results remains to be determined, everyone whom has tried the decompression cure agrees as to its remarkable effectiveness. It cures external GBS (subcutaneous emphysema, a.k.a. tail bubbles), chronic pouch emphysema (pouch bloat) and internal GBS equally well. In fact, as long as treatment is begun early enough, before the emboli have caused irreversible damage, decompression has a very high cure rate. It is safe, provides the affected seahorses with immediate relief, and works for all forms of GBS.

Of course, the home hobbyist lacks the resources to apply decompression at the sort of depths employed by the professionals. But I am discussing the recompression-decompression cure in some detail for two reasons. First of all, a number of hobbyists have managed to construct homemade decompression tanks and chambers, and other enterprising hobbyists may wish to follow their lead (Lisa Hovis, pers. com.). Homemade decompression devices range from simple tubes of water 6-12 inches in diameter and 4-12 feet tall capped at one end, designed merely to increase hydrostatic pressure, to pressurized wide-mouth bottles complete with pressure gauges and bleeder valves (Lisa Hovis, pers. com.). Secondly, I suspect that when enough data comes in we will find that a depth considerably less than 10 feet and relatively short immersion times will prove to be adequate to resolve most cases of GBS.

For example, while working with the Hawaiian seahorse (Hippocampus fisheri) at the Waikiki Aquarium, Karen Brittain found that all the specimens kept in smaller, shallower aquaria developed subcutaneous gas bubbles within a matter of months, whereas H. fisheri that were maintained in tanks at least 1 meter deep fared much better (Bull and Mitchell, 2002, p37). The Hawaiian seahorse remains pelagic all its life, typically being found at least a mile offshore in deep water, and Brittain speculates that H. fisheri needs to migrate to depths unachievable under normal aquarium conditions to maintain proper physiological balance (Bull and Mitchell, 2002, p37). I think she is absolutely correct. It seems likely that H. fisheri follows a daily vertical migration pattern, perhaps synchronized with the movements of plankton. Her findings suggest that tanks a minimum of 3 feet deep can provide a measure of protection against GBS, and custom-built aquaria of those dimensions are certainly within the realm of the home hobbyist.

This remains a fertile field for future research. It has been suggested that should there be an outbreak of GBS in one of your aquariums, transferring the seahorses to an aquarium at least 3 times as deep can decompress the patients and prevent a recurrence of such problems (Wooten and Waughman, 2004). This suggestion has a lot of merit. Even upgrading to a tank that’s twice as deep would be quite advantageous in terms of GBS prevention. Much work remains to be done to develop decompression guidelines for seahorses and to determine what sort of depth is needed to confer protection from GBS to different species. But when it comes to GBS, two things are certain: deeper tanks are healthier for seahorses and recompression can achieve remarkable recoveries.

In short, many times your best bet to cure internal GBS may be to try a moderate form of recompression to help your seahorse recover. What I have in mind is confining the affected seahorse in a flow-through enclosure at the bottom of a 50-gallon Rubbermaid enclosure 40 inches deep, or something similar, for a period of about 3 days. Once the seahorse is immersed at the bottom of this homemade "decompression chamber," you cannot raise it to the surface again for daily feedings. Since your decompression chamber will have no biofiltration, I would simply fast your seahorse while it recompresses at depth. It can easily go without eating for a few days and that will help eliminate any ammonia spikes in the meantime.

If you decide to try this, be sure to keep your makeshift decompression chamber well-aerated. A shallow airstone anchored just below the surface — NOT at the bottom of the decompression chamber! — to provide surface agitation and oxygenation should suffice.
When the recompression period is finished, raise the seahorse to the surface (or lower the water level in the hydrostatic chamber) gradually, in a series of stages, over a period of several hours, to assure that the patient decompresses completely and the gas emboli don’t reform.

Lighting your homemade decompression chamber isn’t really necessary. Seahorses have outstanding visual acuity and see very well under low light conditions (a couple of species are even said to have adopted nocturnal behavior in the face of heavy fishing pressure), so your male seahorse will be able to see well under the ambient light levels that penetrate and 50-gallon bucket. You won’t be feeding him while he’s undergoing the decompression cure, so he doesn’t need to be able to see well enough to hunt small prey or anything like that, and the darkened conditions may give him a sense of security and help him relax, since he won’t be feeling so exposed and vulnerable.

If you want to keep an eye on him periodically while he’s undergoing pressurization, you can just take a quick peek now and then using a flashlight.

When the recompression period is finished, raise the seahorse to the surface (or lower the water level in the hydrostatic chamber) gradually, in a series of stages, over a period of several hours, to assure that she decompresses completely and the gas emboli don’t reform.

One of our other Club members (Christine) recently used this method to cure her seahorse of internal GBS after Diamox baths had been tried unsuccessfully. Here is how Chris described her experience with GBS, and her treatment method with her homemade decompression chamber, in posts to the group:

In a message dated 5/19/2005 1:44:49 PM Central Standard Time, [email protected] writes:

Hi — After 3 days of diamox Heidi was still buoyant (the diamox did not
seem to have helped at all), and swimming with the tip of her head
sticking out of the top of the water, clearly frustrated with her
situation. I looked at her with a magnifying class, and can’t see any
external signs of bubbles. I also don’t see any signs of bloating or
eye problems.

I followed Pete’s suggestions, took her off the diamox to restore her
appetite, gave her 1 day of rest in the hospital tank with clean water
and Kanamycin. She ate well yesterday and this morning. I rigged up
an inexpensive way of submersing her to 3 times the depth of my 30
gallon display tank. (I priced building a 6 ft deep tank out of an
acrylic tube attached to a base, or acrylic rectangles
attached to a base, and it came out to be anywhere from $250 to $400.
They wanted to charge $175 per linear foot of the acrylic tube thick
enough to safely support a 5 or 6 ft column of water). I’m going to
try the cheap method first, and will build a deeper aquarium if she
needs a greater water pressure.

So-I have her in a ‘critter keeper’ (small plastic container with a
lid that has slots in it and a viewing window in the center) with 2
soft rubber hitching posts. The lid has 4 large criss-crossed rubber
bands on it just in case the lid comes off. I made sure there weren’t
any bubbles underneath the critter keeper or underneath the little
clear viewing lid on the top. I bought a 50 gallon rubbermaid bucket
which gives a water depth of 3 1/2 ft when filled. The critter keeper
is inside a 5 gallon white bucket weighted down with a signature
coral, with a rope tied to the bucket handle (made it easy to lower
into the big bucket). I lowered her slowly this morning, and she
seems fine (not pinned against the lid of the critter keeper, and she
is able to go between the 2 hitching posts). I have an airstone going
at the surface of the deep bucket, as Pete suggested. I can see her
with a flashlight. Her breathing looks normal.

I filled the 50 gallon bucket yesterday with the shower! and let it
‘degas’ for one day (also to make sure that it didn’t spring a leak.
It is in the bathtub). The water temp is 70 degrees. I matched the
specific gravity and ph of the hospital tank.

Heidi is going to remain there for 2-3 days, as per Pete’s suggestion.
After that, I will bring her up very slowly (or unload the water from
the big bucket very slowly). I hope this works! Our big bathroom has
been completely taken over with buckets, hospital tank, salt mix, etc.
Wish us luck!
Chris

And here is Christine’s follow-up message after the recompression-decompression treatment was completed:

Hi Pete and Everybody, Heidi is okay! No more floating. I unloaded
the water from my makeshift compression chamber very slowly, as per
Pete’s suggestion, rather than pulled up the critter keeper from the
bottom (much safer to unload the water). I then transferred the
critter keeper she was in to a 5 gal bucket of clean saltwater,
and she swam out when I opened the lid. I decided to do a water
change in the main tank before putting her back in, and used the water
I pulled out of the main tank (74 degrees) to warm up the water she
had been in (70 degrees) to help re-acclimate her to the main tank.
She is eating and swimming as normal, back to her aggressive self with
the turkey baster and Mysis. She is very happy to be back in the
display tank, and is enjoying swimming all around, once again
neutrally buoyant. She was sooo happy to see her favorite coral
colored fake coral. Her color is going back from being dark brown
(her under stress color) to light brown/gold today. I hope to see
her go back to her coral color soon. Thanks for your help Pete!

I hope I never again have a SH with the floaties!
For the record, she was in a critter keeper inside a 5 gal bucket
weighted down with a fake (Signature) coral at the bottom of 40 inches
of water in a Rubbermaid 50 gallon bucket (on wheels-a new bucket). I
had an airstone at the top as per Pete’s instructions. She was in for
2 1/2 days.
Chris

For best results, the decompression sure is often combined with antibiotic therapy. It is a simple matter to administer a dose of antibiotics while the seahorse is submerged at the bottom of the 50-gallon Rubbermaid bucket. (Just don’t perform any water changes while the seahorse is undergoing recompression-decompression.) This would help prevent any secondary infections which are often associated with GBS or stress, and would also cover all the bases if you suspect the underlying cause of your seahorse’s positive buoyancy may be due to a bacterial infection.

For the antibiotic therapy, kanamycin, neomycin, and nifurpirinol are the antibiotics I prefer. I would recommend using two of them (i.e., kanamycin/neomycin or nifurpinol/neomycin) in combination for even greater efficacy, as described below:

Kanamycin

This is a potent broad-spectrum, gram+/gram- antibiotic. It is wonderfully effective for aquarium use because it is one of the few antibiotics that dissolves well in saltwater and that is readily absorbed through the skin of the fish. That makes it the treatment of choice for treating many bacterial infections in seahorses. Kanamycin can be combined safely with neomycin to further increase its efficacy. Like other gram-negative antibiotics, it will destroy your biofiltration and should be used in a hospital tank only.

nifurpirinol (Furanase)

Nifurpirinol is a nitrofuran antibiotic that is the active ingredient in many commercial preparations designed for use in the aquarium. It is stable in saltwater and rapidly absorbed by fish, making it the preferred treatment for fungal infections in seahorses (Burns, 2002). Nifurpirinol is photosensitive and may be inactivated in bright light, so use this medication only in a darkened hospital tank.

Nifurpirinol may be combined with neomycin (see below) to produce a potent broad-spectrum medication that’s effective against both fungus and bacteria. Nifurpirinol/neomycin is therefore a great combination to use when you’re not certain whether the infection you are treating is fungal or bacterial in nature.

neomycin sulfate

Neomycin is a very potent gram-negative antibiotic. Most of infections that plague marine fish are gram-negative, so neomycin sulfate can be a wonder drug for seahorses (Burns, 2002). As mentioned above, it can even be combined with other medications such as kanamycin or nifurpirinol for increased efficacy. For example, kanamycin/neomycin is tremendous for treating bacterial infections, while nifurpirinol/neomycin makes a combination that packs a heckuva wallop for treating mixed bacterial/fungal infections or problems of unknown nature. Keep it on hand at all times.

Neomycin will destroy beneficial bacteria and disrupt your biological filtration, so be sure to administer the drug in a hospital tank.

One other thing to keep in mind is water temperature. Since you’re homemade decompression chamber is unheated, the water temperature will gradually fall over the three-day treatment period. This is fine and to be is expected — and even beneficial in many respects — but it does mean that once the decompression period is over, you may have to acclimate the seahorse for temperature before returning the patient to the main tank.

Best of luck resolving your seahorses’ problems with positive buoyancy/GBS and restoring them to good health again, Chris!

Respectfully,
Pete Giwojna

Post edited by: Pete Giwojna, at: 2006/12/10 18:00

Dear Chris:

Thank you very much for clarifying the situation regarding your floating seahorses. If they are still juveniles and none of them have developed pouches as yet, then we can rule out pouch emphysema and air bubbles trapped in their pouches as the cause of their positive buoyancy.

If the juveniles are very young — just a few weeks old, for example — they may be floating because they have a gulped air, in which case neither Diamox nor pressurizing them in a homemade decompression chamber will resolve the problem. Newborn seahorses need special nursery tanks (i.e., kriesels or pseudokreisels) with gentle currents designed to keep them away from the surface so that they don’t accidentally ingesting air and become floaters. Seahorse fry that develop problems with positive buoyancy and become floaters are unable to feed properly and are doomed to starvation.

Methods for measuring dissolved oxygen in the aquarium can be as simple or as sophisticated as you desire, ranging from basic test kits under $10 to electronic probes costing hundreds of dollars. Fortunately, the humble seahorse keeper doesn’t require anything too fancy along those lines, and the basic O2 test kits will do nicely for our purposes.

For instance, the Tetra Oxygen Test Kit (TetraTest 02) is a good liquid reagent test kit for fresh or saltwater with simple color scales for comparing readings that tests for 02 in the range of 2-14 PPM. It will cost you between $8.50 to $14 depending on where you shop and should be available at any well-stocked LFS. Salifert also makes a nice 02 Test Kit (their 02 Profi-Test) that will run you about $20.

Either of those test kits fit the bill very well and are worthwhile investments for the seahorse keeper.

Dissolved Oxygen (02): Optimum level = 6 – 7 ppm

High levels of dissolved oxygen are vital to the well being of both fish and invertebrates. The key to maintaining high O2 levels in the aquarium is good circulation combined with surface agitation (Webber, 2004). Wet/dry trickle filters and protein skimmers facilitate efficient gas exchange and oxygenation. It is important for the hobbyist to monitor the dissolved oxygen levels in the aquarium because a drop in O2 levels is often an early indicator of impending trouble — a precursor of problems ahead. A drop in O2 levels will tip off the alert aquarist and allow corrective measures to be taken, nipping the problem in the bud before it adversely affects his seahorses. For example, a drop in O2 levels could be an early indicator of overcrowding — a signal that your system has reached its carrying capacity. Or it may merely signal a rise in the water temperature due to a summertime heat wave or indicate that the tank is overdue for a water change and/or a thorough cleaning to remove excess organics and accumulated detritus. Or it could be telling you that your tank is under circulated and you need to increase the surface agitation and water movement.

The point is that checking the O2 levels in your aquarium can alert you to impending problems and allow you to do something about them before they have dire consequences. A drop in O2 levels is often the first sign of a water quality problem and it can tip off the alert aquarist that trouble is brewing before his seahorses are gasping for air in obvious respiratory distress. Checking the dissolved oxygen levels regularly is the next best thing to continuously monitoring the Oxidation-Reduction Potential (ORP) or redox of the water, which is a luxury few hobbyists can afford.

In your case, Chris, we would be concerned about gas supersaturation rather than low oxygen levels. If the water become supersaturated with oxygen or other gases, that can lead to the formation of gas emboli in the blood and tissues of the seahorses, resulting in various forms of Gas Bubble Syndrome (GBS), as we have previously discussed. But if your youngsters are only three or four weeks old, then they are much more likely to be floating due to accidentally ingesting air than they are to be suffering from GBS.

Unfortunately, Ocean Rider only ships within the continental United States, Chris, so that won’t be an option for you in Singapore. However, seahorses typically tolerate all of the usual fish medications at the appropriate therapeutic dosages without difficulty. You need not consider them delicate or sensitive when it comes to disease treatments. Very likely, any of the medications designed for aquarium use that are available to you in Singapore are safe to use with your seahorses.

As for all the different diseases that seahorses are susceptible to, what the symptoms are, and how to treat them, that’s a topic that goes well beyond the limits of this simple discussion forum to address properly, but I’ll try my best to give you an idea of what to look out for, Chris. When it comes to health problems, seahorses are like other tropical marine fish. They are susceptible to the usual diseases and infections and parasites that plague other reef fish, as well as a few afflictions that are specific to seahorses (e.g., prolapsed pouch, white tail disease, and gas bubble syndrome). The bony exoskeleton and protective slime coat of Hippocampus gives the seahorse limited immunity from certain ectoparasites such as marine ich (Cryptocaryon irritans) and marine velvet (Amyloodinium), so the telltale white spots that characterize those conditions may never show up (or may be visible only on the unarmored fins). So those particular diseases are relatively uncommon in seahorses, although when they do occur, the parasites can still freely invade the seahorse’s gills, with deadly results.

Ocean Rider seahorses come to you direct from a High-Health aquaculture facility and are certified to be free of pathogens and parasites when they arrive, so if you can provide them with a stress-free environment and proper care, you should find them to be quite hardy and relatively disease resistant. But that may not be the case with your Vietnamese seahorses.

Seahorses that are subjected to chronic stress, which alters their blood chemistry, affects key hormones, and suppresses their immune system, become vulnerable to diseases and health problems just like any other fish. So the best thing you can do for your seahorses is to create a stress-free environment for them in which they feel right at home. We will discuss how to accomplish that and eliminate many of the common aquarium stressors later in this message, Chris, but first let me review some of the obvious signs of stress or illness you should be aware of.

Respiratory distress is one such sign. Seahorses that are stressed or suffering from gill disease or parasites that attack the gills will exhibit rapid respiration, labored breathing, huffing, panting, yawning or coughing behavior, and other indications of respiratory distress. So familiarize yourself with your seahorse’s normal respiration rate, which will vary somewhat with water temperature and their activity level or degree of arousal/excitement, and subsequent changes in their normal breathing pattern can alert you to a possible problem.

Your seahorses’ respiration rate may increase naturally when they are feeding, actively courting, being handled, or excited in general, and then return to their normal resting respiratory rate afterwards. That’s natural and nothing to be concerned about. Symptoms of respiratory distress are ordinarily pretty obvious and you should have no trouble determining when your seahorse is laboring or struggling to breathe.

Seahorses that are stressed may also go off their feed, which is another obvious symptom that’s easy for the diligent aquarist to detect. So take a moment to enjoy the show when feeding your seahorses. Make sure they’re all eating well, and use this opportunity to look them over closely for wounds, injuries, or signs of disease. Seahorses are natural-born gluttons. Ordinarily, these galloping gourmets are ALWAYS hungry, so when one of these chow hounds is off its feed, that’s often an excellent early indicator that something’s wrong. Early detection of a potential problem can be the key to curing it, so it’s a good idea for the alert aquarist to observe his prize ponies while they put on the ol’ feed bag. Make sure they all show up for mess call, are acting normally, and have a well-rounded abdomen when they’re done eating.

Abnormal changes in coloration are another indicator of stress and certain disease problems. For example, seahorses will often darken over their entire bodies in response to stress, and pallor can be a sign of low dissolved oxygen levels or high CO2 levels since seahorses may blanch when subjected to hypoxic conditions. Skin infections and parasites that attack the skin will often cause a localized loss of pigmentation or discoloration, so be on the lookout for pale patches or white blotches that appear on your seahorse suddenly, particularly if these pale spots are not symmetrical (that is, they don’t appear in the same place on both sides of the seahorse’s body).

However, it’s important to distinguish between normal color changes and transitory color phases that all seahorses go through, and the type of abnormal changes in coloration we have been discussing above. Seahorses are truly the chameleons of the sea with a propensity for changing color in response to a wide range of environmental factors, hormonal influences, and behavioral interactions, or simply to better blend into their background.

With a little experience, you will become familiar with their normal color pattern and the transitory color phases they occasionally go through, which will make it easy to determine if an unnatural marking or suspicious pale blotches suddenly appears.

The hobbyist should also be aware that there are any number of environmental conditions that can affect the coloration of their seahorses, often by affecting the ability of chromatophores to contract and expand. These include the following factors:

Stress — seahorses often respond to stress by darkening.

Emotional state — when excited, seahorses typically brighten in coloration, reflecting a state of high arousal.

Competion for mates — dominant individuals brighten; subordinate seahorses darken in submission.

Poor water quality — high levels of nitrogenous wastes (e.g., ammonia, nitrite or nitrate) can cause chromatophores to contract and colors to fade.
O2/CO2 — low oxygen levels (or high CO2 levels) can cause colorful seahorses to fade and they will blanch when subjected to hypoxic conditions.

Background colors — seahorses will often change color in order to blend in with their immediate surroundings.

Medications — some antibiotics and malachite-green-based remedies negatively affect color.
Tankmates — seahorses may change their base coloration to blend in with the rest of the herd or to match their mate (or a potential partner).

Temperature — chromatophores tend to contract at high temperatures, causing colors to fade; cooler temps can make pigment cells expand, keeping colors bright.

Disease — skin infections (bacterial, fungal, or parasitic) can cause localized loss of pigmentation or discoloration of the affected areas.

Diet — seahorses cannot synthesize the pigments used in their chromatophores. It is therefore important to enrich their food with pigments such as carotenoids in a form that’s easy for them to absorb. If color additives are not provided, the chromatophores will gradually lose their pigments and the seahorse’s color can fade. Vibrance, for example, is exceptionally rich in Vitamins A and C as well as natural carotenoids, which are not found in Mysis relicta. This is important because the carotenoids are a class of yellow to red pigments, which include the carotenes and the xanthophylls. Like all cells, individual pigment cells have a limited life expectancy in the body and must be regularly renewed. Marine organisms cannot synthesize carotenoids, so if they do receive adequate amounts in their diet, they will have difficulty replenishing their red and yellow pigments. This means that the colors of bright yellow, orange, and red seahorses will gradually fade over time if their daily diet is lacking in carotenoids. So don’t neglect the enrichment step in your daily feeding regimen! If seahorses are fed a strict diet of Mysis relicta without additional enrichment, they may begin to develop dietary deficiencies over time, and both their health and coloration will eventually suffer.

Beware of tenderness and especially a loss of color or prehensility in your seahorse’s tail.
Tail rot and white tail disease typically begin with a loss of prehensility in the very tip of the tail (Giwojna, Oct. 2003). At this stage, the seahorses can grasp large objects just fine, but cannot take hold of slender objects with a small diameter (Leslie Leddo, pers. com.). Next the loss of prehensility spreads further up the tail and the seahorses begin to act as if their tails are very tender and sensitive. They will drape their tails over objects rather than grasping onto them and begin to drag their tails behind themselves, often arching the end of their tail upward in the shape of "U" (rather than the usual "J" or tight coil) as if to lift it off the ground and keep it from touching anything (Leddo, pers. com.).

Scratching and the erratic behavior are often an indication of the irritation ectoparasites cause. So when a seahorse attempts to scratch itself with its tail, or repeatedly attempts to scratch itself by rubbing against various objects, it’s often a sign of a parasitic infestation. If such symptoms persist, you’ll need to treat the seahorses with a good antiparasitic.

Buoyancy problems are another obvious sign of a health problem. Positive buoyancy — the tendency to float — can result from a number of causes such as hyperinflation of the swimbladder, pouch gas, or various forms of Gas Bubble Syndrome (GBS). Negative buoyancy — the tendency to sink — can be an indication of generalized weakness, and underinflated gas bladder, or fluid (ascites) building up within the abdomen or coelomic cavity.

Those are some of the signs of stress and early symptoms of health problems the diligent seahorse keeper should be aware of, Chris. One of the best ways to prevent bacterial infections and other disease problems is to provide them with a stress-free environment. Many of the parasites and pathogens that plague our pampered ponies are ubiquitous — present in low numbers in most everyone’s systems or within the seahorse’s body itself (Indiviglio, 2002). As a rule, healthy fish resist such microorganisms easily, and they only become a problem when seahorse’s immune system has been impaired, leaving it susceptible to disease (Indiviglio, 2002). Chronic low-level stress is one of the primary factors that suppresses the immune system and weakens the immune response, opening the way to infection and disease (Indiviglio, 2002). Long-term exposure to stressful conditions is very debilitating. Among other effects, it results in the build up of lactic acid and lowers the pH of the blood, which can have dire consequences for seahorses for reasons we’ll discuss later.

When disease breaks out in an established aquarium it is therefore generally an indication that something is amiss with your aquarium conditions. A gradual decline in water quality is often a precursor of disease (Indiviglio, 2002). Poor water quality is stressful to seahorses. Prolonged stress weakens their immune system. And an impaired immune system leaves the seahorse vulnerable to bacterial, viral, and fungal infections to which healthy, unstressed seahorses are immune. As if that weren’t bad enough, there are a number of environmental diseases that are caused directly by water quality problems.

With this in mind, it’s important to review the most common stressors of captive seahorses. These include the design of the aquarium itself. A poorly designed seahorse setup that lacks adequate cover and shelter, or has too few hitching posts, will be stressful to the occupants (Topps, 1999). Seahorses are shy, secretive animals that rely on camouflage and the ability to conceal themselves for their safety and survival. A sparsely decorated tank that leaves them feeling vulnerable and exposed will be a source of constant stress (Topps, 1999). The seahorse setup should have plenty of secure hiding places so they can conceal themselves from view completely whenever they feel the need for privacy. It should be located in a low traffic area away from external sources of shock and vibration.

Needless to say, rapid fluctuations in temperature, pH, salinity and other aquarium parameters must also be avoided. A large aquarium of 40 gallons or more provides much greater stability in that regard than does a smaller setup. The greater the water volume in the aquarium and sump, the more stable the system will be.

Heat stress is especially debilitating and dangerous for seahorses due to a number of reasons (Olin Feuerbacher, pers. com.). For one thing, elevated temperatures can have a very detrimental effect on the immune system of fishes. This is because many of the enzymes and proteins involved in their immune response are extremely temperature sensitive (Olin Feuerbacher, pers. com.). Some of these protective enzymes can be denatured and inactivated by an increase of just a few degrees in water temperature (Olin Feuerbacher, pers. com.). So when seahorses are kept at temperatures above their comfort zone, their immune system is compromised and they are unable to fend off diseases they would normally shrug off.

At the same time heat stress is weakening the seahorse’s immune response, the elevated temperatures are increasing the growth rate of microbes and making disease organisms all the more deadly. Research indicates that temperature plays a major role in the regulation of virulence genes (Olin Feuerbacher, pers. com.). As the temperature increases, virulence genes are switched on, so microorganisms that are completely harmless at cooler temperatures suddenly become pathogenic once the water warms up past a certain point. Thus both the population and virulence of the pathogens are dramatically increased at higher temperatures (Olin Feuerbacher, pers. com.).

This is true of Columnaris and certain types of Vibrio. At cool temperatures these bacteria are relatively harmless, but at elevated temperatures they become highly contagious, virulent pathogens that kill quickly.

In short, it’s doubly important to keep seahorses at the proper temperature. Because of the reasons mentioned above and the fact that water holds less and less dissolved oxygen as it warms up, seahorses generally tolerate temps at the lower end of their preferred range much better than they handle temperatures at the upper limit of their range.

Incompatible tankmates are also stressful for seahorses. This includes not only aggressive, territorial fishes and potential predators but also inoffensive species that are restless, active fishes. Seahorses may be uneasy around fishes that are always on the go, swimming tirelessly back and forth.

Other common stressors for seahorses include overcrowding, overfeeding, stray voltage, and a host of issues related to water quality: ammonia or nitrite spikes, high nitrate levels, inadequate circulation and oxygenation, high CO2 levels and low 02 levels, low pH, etc., etc., etc (Giwojna, Jun. 2002).

In short, if hobbyists provide their seahorses with a stress-free environment, optimum water quality, and a nutritious diet, they will thrive and your aquarium will flourish with a minimum of problems. Preventing disease in the first place is infinitely preferable to trying to treat health problems after the fact. Good seahorse husbandry and diligent maintenance will be rewarded; sooner or later, negligence and poor aquarium management will be punished.

When disease breaks out in an established aquarium it is therefore generally an indication that something is amiss with your aquarium conditions. A gradual decline in water quality is often a precursor of disease (Indiviglio, 2002). Poor water quality is stressful to seahorses. Prolonged stress weakens their immune system. And an impaired immune system leaves the seahorse vulnerable to bacterial, viral, and fungal infections to which healthy, unstressed seahorses are immune.

Here’s some relevant information from my new book (Complete Guide to Greater Seahorses in the Aquarium, TFH Publications, unpublished) to will give you an indication of what some of these diseases and disease organisms looked like.. (I should point out that these are very brief excerpts which I have limited to the pertinent information that will help you identify various pathogens and parasites using a microscope. The actual discussions of these disease problems in my book are quite comprehensive, with detailed descriptions of the diseases and their symptoms, diagnostic procedures, preventative measures for each specific problem, contributing factors, discussions of treatment options, and complete treatment instructions and protocols.)

White Patch Disease: Myxobacteria (Marine Columnaris)

Marine columnaris is a highly contagious disease caused by a Myxobacterium (Flexibacter sp.) that corresponds to the columnaris infections so commonly seen in freshwater fish (Basleer, 2000). The bacterium Flexibacter is a long, slender rod-shaped organism (0.5- 1.0 microns in diameter, and some 4-10 microns long) that is easily identified under the microscope by its characteristic gliding motion (Dixon, 1999). They are unusually mobile bacteria. They are very active when observed microscopically, gliding rapidly across the viewing field (Dixon, 1999). This family of bacteria (Cytophaga or Myxobacteria) causes a condition commonly known as columnaris because of their tendency to stack up in columns (Prescott, 2001b). When large numbers of the bacteria pile up, they form distinctive haystacks several layers thick where the infection is heaviest (Dixon, 1999).

Marine Ulcer Disease, a.k.a. Hemorrhagic Septicemia, a.k.a. "Flesh-Eating Bacteria", a.k.a. Vibriosis

Marine ulcer disease is a particularly nasty type of infection that most hobbyists have come to know as "flesh-eating bacteria," and indeed it can often be attributed to bacteria, most notably Vibrio or Pseudomonas species (Giwojna, Nov. 2003). Vibrio in marine fish is the equivalent of the Aeromonas bacteria that plague freshwater fishes (Dixon 1999; Basleer 2000), causing external hemorrhagic ulcers (bloody lesions). Vibriosis is probably the most common bacterial infection of captive seahorses and one of the most difficult to eradicate from your system. Vibrio bacteria are motile gram negative rods, which measure about 0.5 X 1.5 micrometers (Prescott, 2001). When grown on suitable media they appear as shiny, creamy colored colonies (Prescott, 2001).

Mycobacteriosis, a.k.a. Piscine Tuberculosis, a.k.a. Granuloma Disease

Fish tuberculosis is caused by pathogenic Mycobacteria, of which two different species are the primary culprits: Mycobacterium marinum and Mycobacterium fortuitum (Giwojna, Sep. 2003). Unlike most bacteria the plague fish, these Mycobacteria are gram-positive, and take the form of pleomorphic rods that are acid-fast and nonmotile (Aukes, 2004). When cultured on solid media, they form cream-colored to yellowish colonies (Aukes, 2004).

Intestinal Flagellates

Intestinal flagellates are microscopic organisms that move by propelling themselves with long tail-like flagella (Kaptur, 2004). Such flagellates can be found in both the gastrointestinal and reproductive tracts of their hosts. In low numbers they do not present a problem, but they multiply by binary fission, an efficient means of mass infestation when conditions favor them (such as when a seahorse has been weakened by chronic stress), Kaptur, 2004. When they get out of control, these parasites interfere with the seahorse’s normal digestive processes such as vitamin absorption, and it has difficulty obtaining adequate nourishment even though it may be eating well and feeding heavily (Kaptur, 2004). Suspect intestinal parasites are a work when a good eater gradually wastes away despite its hearty appetite (Giwojna, Dec. 2003). Their presence can be confirmed by examining a fecal sample under a microscope, but they can be easily diagnosed according to the more readily observed signs described below (Kaptur, 2004).

The symptoms to look for are a seahorse that’s losing weight or not holding its own weightwise even though it feeds well, or alternatively, a lack of appetite accompanied by white stringy feces (Kaptur, 2004). When a seahorse stops eating aggressively and begins producing white, stringy feces instead of fecal pellets, that’s a clear indication that it’s suffering from intestinal flagellates (Kaptur, 2004).

Intestinal Nematodes (Roundworms)

Intestinal nematodes (roundworms) are usually spotted visually. This happens when one or more of the nematodes are actually sighted protruding from the seahorse’s vent, where they appear as red hairlike worms emerging from the anus. Weight loss is the primary symptom of a heavy cestode infestation. Suspect tapeworms when an aggressive eater gradually wastes away despite a hearty appetite.

A case like that is usually due to either intestinal flagellates or cestodes. To confirm which is the culprit, an examination of the fecal pellets is often revealing. If microscopic organisms having long "tails" or flagella are present in the sample, treat with metronidazole. If not, administer fenbendazole. There are very few intestinal parasites that cannot be controlled with one or the other of these medications.

Glugea (White Boil Disease)

White boil disease is an insidious affliction that is specific to seahorses and pipefish. It is fatal, highly contagious, and incurable. In the older literature, Glugea is often referred to as "white spot disease," since the first outward system is the appearance of tiny white spheres (pinhead to pin point in size) on the skin. Thus, Glugea may easily be mistaken for an outbreak of Cryptocaryon at this early stage of the disease. Indeed, you will sometimes read that Glugea can be treated with copper sulfate. That is untrue; such reports are based on misdiagnosed cases and confusion over which type of white spot disease is at work. Don’t make that mistake. Copper has no effect on microsporidians, which spread from within the host, and Glugea can readily be distinguished from Cryptocaryon as the disease progresses.

The most commonly seen form of this dread affliction is caused by the microsporidian parasite, Glugea heraldi, which may attack any part of the body, including internal organs, depending on how the disease progresses. Spores enter the host after being accidentally ingested while feeding or simply breathing. When it spreads outward, the first symptoms of Glugea are often white spots that merge together and coalesce to form whitish-gray, spore-filled ulcers called xenomas. When the tissue begins to break down and the xenomas rupture, they release new spores that infect additional hosts. This is what makes Glugea so contagious.

There is a good description of a case of G. heraldi, including photographs of the infectious stages of the microsporidian, in a paper titled ”Parasitic infection of the seahorse Hippocampus erectus–a case report” by Amanda Vincent and Clifton-Hadley which appeared in the Journal of Wildlife Disease in 1989 (Volume 25, Number 3, pages 404-408.) Hobbyists with access to a good microscope may be able to compare notes and confirm their diagnosis through a microscopic examination.

Uronema marinum

Uronema marinum is the marine equivalent of the Tetrahymena pyriformis parasites that plague freshwater fish (Basleer, 2000). Uronematids are probably the most commonly encountered protozoan parasites of seahorses in the aquarium. They frequently plague wild-caught seahorses and store-bought fish in particular. Unfortunately, they are also one of the deadliest and difficult to eradicate marine parasites.

They live in seawater and normally feed on bacteria and dead tissue, but they are opportunistic invaders that are always on the lookout for food, and are quick to take advantage of weakened fish (Kollman, 2003). It is when conditions favor them and their numbers get out of hand that Uronema becomes a problem. Under those circumstances, they soon begin to attack healthy tissue as well as dead material, invading the gills and muscles, eating red blood cells, and infiltrating the internal organs (Kollman, 2003).

Microscopic examination of skin smears can confirm the diagnosis of Uronema. Under the microscope, Uronema marinum parasites appear as pear-shaped, single-celled ciliates with a single large macronucleus and long hairlike cilia at the rear end (Kollman, 2003). Numerous small (35-50 microns), fast-moving, oval or pear-shaped parasites will appear on skin and fin smears (Basleer, 2000).

Amblyoodinium ocellatum (Marine Velvet, a.k.a. Coral Reef Disease)

Marine Velvet is another highly contagious disease caused by protozoal parasites. In this case, the parasites are dinoflagellates and Oodinium is fatal if untreated. These parasites attack the gills primarily, as well as the skin of their hosts, and the fresh-swimming stage of the Amyloodinium protozoans causes massive reinfection of aquarium fishes, leading to death by asphyxiation (Basleer, 2000). Typical symptoms include huffing and respiratory distress, excessive mucus production, and scratching (Basleer, 2000).

These unicellular parasites use their rootlike rhizoids to anchor themselves deep in the mucosa of their host (Basleer, 2000). They do their greatest damage to the mucosa layer, thus destroying the integrity of the fish’s slime coat. This weakens the fish’s first line of defense, leaving them susceptible to secondary infections that produces bloody red patches of skin in the advanced stages of the disease (Basleer, 2000). The characteristic dusting of fine white or yellow spots often never appears when seahorse’s are the hosts, making this condition difficult to diagnose for the seahorse keeper.

Positive identification can be made by microscopic examination. The Oodinium parasites are easily visible on skin or gill smears at a magnification of 100x or 200x power (Basleer, 2000). They appear as dark, cone-shaped unicellular organisms measuring 50-60 microns embedded in tissue (Basleer, 2000).

Cryptocaryon Irritans (Saltwater Ick, a.k.a. White Spot Disease)

Cryptocaryon is another protozoal parasite that invades the gills and burrows into the skin of marine fishes, including seahorses. The life cycle and modus operandi of Cryptocaryon are very similar to that of Amyloodinium ocellatum, so it should not be surprising that it also produces strikingly similar symptoms. Infected fish show labored breathing, excess mucus, and scratch themselves against objects. Along with the characteristic pinhead-sized white spots and excess mucus production, affected fish sometimes show cloudy eyes and secondary infections (Basleer, 2000). The latter can result in skin rot and fin rot accompanied by red or pale patches on the body of the fish (Basleer, 2000).

The white spots seen on infected fish are the adult stage of the parasite, known as trophonts (Basleer, 2000). When they mature, they fall off the fish and encyst themselves. The encapsulated parasites are known as tomonts (Basleer, 2000). Well protected within these cysts, the tomont stage cannot be killed by any medications. The encapsulated tomonts divide into hundreds of daughter cells, which develop into small, ciliated, free-swimming parasites, called tomites (Basleer, 2000). When the cysts rupture, the motile tomites swarm out to seek a new host. In the aquarium, they reinfect the same fishes, and bore into the mucosa of the skin, gills, and fins of their hapless hosts. Once embedded in the tissue, they mature into typical trophonts, appearing as pinhead-sized white spots on most fish, and start the cycle of infection all over again (Basleer, 2000). It is these heavy infestations that can overwhelm even healthy fish.

At 100x magnification, Cryptocaryon parasites can easily be identified in skin and fin smears. They appear as large, dark, bell-shaped or conical organisms measuring about 350-400 micrometers in diameter (Basleer, 2000).

Brooklynella hostilis (Clownfish Disease)

Typical symptoms include turbidity of the skin (a thick, whitish mucus coating in the affected areas), cloudy eyes and breathing difficulty (Basleer, 2000). At first there are no apparent symptoms, but cell division occurs very rapidly and Brooklynella parasites multiply to life-threatening numbers quite quickly in a closed system (Basleer, 2000). These ciliated parasites attack the gills first and then spread to the skin. Clear signs of infection soon appear in the form of respiratory distress and strong turbidity of the skin, often accompanied by excess mucus sloughing in shreds and tatters or hanging off in dark slimy strings (Basleer, 2000). Loss of appetite and listlessness soon follow and skin lesions develop where the turbidity or change in coloration had been, often as the result of secondary bacterial infections. Skin rot and fin rot are common in the advanced stages of Brooklynella. Heavily infected seahorses may die within 24 hours after the first symptoms appear (Basleer, 2000

The symptoms of Brooklynella are similar to those of other parasites that commonly attack the skin and gills of their hosts. An exact identification can only be made through microscopic examination of the parasites. This requires making a wet-mount of mucus taken from the skin of the infected fish, which can be studied under the microscope. The Brooklynella parasites are heart- or kidney-shaped organisms measuring 50-80 microns by 30-50 microns (Fenner, 2003c). A large oval macronucleus and several micronuclei and other endoplasmic organelles should be visible, as should the hairlike cilia it uses for locomotion (Fenner, 2003c). Another key feature to look for is a prominent adhesion organ on the posterior-ventral area (i.e., located on the underside of the parasite at the rear; Fenner, 2003c). This is the device the parasite uses to attach itself to the unfortunate host.

Costia & Cryptobia

These are flagellated parasites that are commonly found on skin and gills of freshly imported marine fishes (Basleer, 2000). Affected fishes exhibit the usual symptoms of parasitic infection by protozoans, including heavy mucus build up, rapid respiration, loss of appetite, and sometimes darkening or turbidity of the skin (Basleer, 2000). In the latter stages, secondary bacterial infections often taken hold and complicate the picture, causing pale skin patches or red patches, which lead to skin rot and fin rot (Basleer, 2000).

Costia are small, bean-shaped flagellates that are very similar to the Ichthyobodo and Costia sp. that parasitize freshwater fish (Basleer, 2000). Cryptobia are similar in appearance. They are small, mobile parasites measuring about 5-12 microns in length with a long tail (flagella) used for locomotion (Basleer, 2000). Both these flagellates can be readily identified in skin and fin smears using a microscope at 200x to 300x magnification (Basleer, 2000).

Snout Rot

Snout rot is the result of an infection, which can be either bacterial or fungal in nature (Giwojna, Oct. 2003). The initial symptoms are discoloration and slight swelling in the affected area of the snout. At this early stage, the seahorse is often not bothered by its affliction and eats and feeds normally. But don’t let that lead to complacency — you cannot afford to take a "wait-and-see" approach with this affliction! As the disease progresses, the infection will begin to eat away the underlying tissue, and if left untreated, snout rot is both disfiguring and deadly (Giwojna, Oct. 2003). The tip of the snout is often the first area affected, becoming inflamed and eroding away, and once its mouthparts are involved, the seahorse can no longer be saved. It is unable to feed, its jaws disintegrate, and the tip of the snout is progressively eaten away (Giwojna, Oct. 2003).

There is considerable anecdotal evidence suggesting that bacterial snout rot can be differentiated from the fungal form of the disease by a close visual inspection (a hand lens or magnifying glass may be required for this). If the snout rot is due to a fungal infection, the affected area of the snout is often pinkish and may appear lumpy or raised, whereas when bacterial infection is at work, white tissue is exposed upon flaking or sloughing of the skin (Giwojna, Oct. 2003). Thus, many hobbyists maintain that if the affected area of the snout looks pinkish, it’s fungus, but if the affected area appears whitish, it’s a bacterial problem (Giwojna, Oct. 2003). This information can help guide you to the appropriate treatment.

If you have seahorses with any of the symptoms described above, do a search on this forum for that particular disease problems and you will find detailed suggestions regarding treatment options, Chris.

Finally, there is an excellent new book about the diseases of seahorses that you would find very informative. Dr. Martin Belli, Marc Lamont, Keith Gentry, and Clare Driscoll have done a terrific job putting together "Working Notes: A Guide to the Diseases of Seahorses." Hobbyists will find the detailed information it contains on seahorse anatomy, the latest disease diagnosis and treatment protocols, and quarantine procedures to be extremely useful and helpful. It has some excellent dissection and necropsy photos as well as a number of photos of seahorses with various health problems. This is one book every seahorse keeper should have in his or her fish-room medicine cabinet, and I highly recommend it! In time of need, it can be a real life saver for your seahorses. It’s available online at the following web site:

http://www.cafepress.com/seahorses.55655887

Floating seahorses that are unable to feed because of their condition will die unless you can relieve their positive buoyancy, and allow them to swim and feed normally again. If your juvenile seahorses that are floating and unable to swim normally are more than a few weeks old, indicating they have not accidentally ingested air at the surface, and you are unable to obtain Diamox, then I would suggest you try pressurizing them in a homemade decompression chamber, as we discussed in my previous post. In the meantime, do your best to maintain optimum water quality and get your pH back up into the normal range (8.1-8.4), Chris.

Best of luck getting your floating seahorses back to normal, Chris!

Respectfully,
Pete Giwojna