Swimming upside-down is a sure indication that your seahorse as the buildup of gas in its pouch, which is causing positive buoyancy or the tendency to float. We need to address the problem of its positive buoyancy first and foremost. Positive buoyancy is often a symptom of more serious problems with Gas Bubble Syndrome (GBS), which require immediate treatment. So let’s focus on resolving the buoyancy problem for now.
Positive buoyancy or the tendency to float can result from a number of different causes. For example, it may be due to hyperinflation of the swimbladder. As in many other bony fishes, the seahorse’s gas bladder functions as a swim bladder, providing the lift needed to give them neutral buoyancy. In essence, the swim bladder is a gas-filled bag used to regulate buoyancy. Because the seahorse’s armor-plated body is quite heavy, this organ is large in Hippocampus and extends well down into the body cavity along the dorsal boundary
When the swimbladder is inflated with just the right amount of gas, the buoyancy provided by this gasbag exactly cancels out the pull of gravity, and the seahorse will neither tend to float nor tend to sink. This condition is known as neutral buoyancy, and it makes it very easy for the seahorse to swim and maneuver almost effortlessly. But when the swimbladder is over inflated with gas, the seahorse will have positive buoyancy and must exert a lot of energy when swimming in order to counteract the tendency to float. And if the swimbladder is underinflated, the seahorse has negative buoyancy and must swim hard in order to avoid sinking.
So a hyperinflated gas bladder is one possible reason why your seahorse may be floating, and if the seahorse is a female, that’s the most likely cause. If your seahorse is a male, positive buoyancy can also result due to a buildup of gas within its pouch. This can be from something as harmless as air bubbles becoming entrapped within the marsupium during its rigorous pouch thus plays when the seahorse was courting, or it could be due to a more serious problem such as chronic pouch emphysema, a form of GBS.
In your case, Michael, thank you have noticed a swollen area in your male’s pouch, I think you are dealing with excess gas building up in its marsupium.
At the first sign of a bloated pouch accompanied by any indications of positive buoyancy, the pouch should be “burped” or the trapped gas should be evacuated using a fine catheter. That will provide the affected seahorse with immediate relief, and if this simple first-aid measure resolves the issue, all is well and good.
In that case, the problem was no doubt due to simple pouch bloat, a harmless sort of gas build up that is entirely unrelated to chronic pouch emphysema. Pouch bloat can be caused by gas produced by the decay of embryonic material and the remains of placental tissue or other organic matter (possibly even stillborn young) within the brood pouch, if the male is unable to flush it out and cleanse it properly by pumping water in and out during its pouch displays (Cozzi-Schmarr, per. com.). And in some isolated cases, it’s possible that a bacterial infection of the pouch may also be involved (Cozzi-Schmarr, 2003). But it is far more common for pouch bloat to result from air bubbles trapped in the pouch during courtship displays, especially if the male chooses to display in the bubble stream produced by an airstone or bubble wand or bubble curtain (Strawn, 1954).
However, hobbyists should be aware that even a case of simple pouch bloat can contribute to recurring pouch emphysema, a much more serious problem, if it is not handled properly. The simple act of struggling against the positive buoyancy that results from pouch bloat can alter the seahorse’s blood chemistry, and result in full-blown PE via acidosis of the blood if the problem is not relieved promptly.
The first indication of pouch bloat (or pouch emphysema) is a loss of equilibrium. The seahorse’s center of gravity shifts as the gas accumulates in its pouch, and it will have increasing difficulty swimming and maintaining its normal posture, especially if it encounters any current. It will become apparent that the seahorse has to work hard to stay submerged, as it is forced to abandon its usual upright swimming posture and swim with its body tilted forward or even horizontally in order to use its dorsal fin to counteract the tendency to rise.
The uncharacteristically hard work it must do while swimming means the hard-pressed seahorse builds up an oxygen debt in its muscles, and the lactic acid that builds up as a result of anaerobic metabolism further disrupts its blood chemistry and worsens the situation. It will struggle mightily in a losing battle against its increasing buoyancy until finally it can no longer swim at all, bobbing helplessly at the surface like a cork whenever it releases its grip on its hitching post. At this point, its pouch will be obviously swollen and bloated.
It is imperative that the gas be evacuated and neutral buoyancy restored long before that happens in order to assure that the affected seahorse is subjected to the least possible stress and does not have to overexert itself for an extended period. The longer it must fight against positive buoyancy, the greater the chances its blood will be acidified in the process and the more likely it becomes that a case of basic pouch bloat can progress into recurring pouch emphysema.
If your seahorses a male and his pouch looks bloated and distended, air trapped within its pouch or gas building up in its pouch is the most likely cause for the positive buoyancy. In that case, the appropriate treatment would be to evacuate the gas or air from the seahorse’s pouch as mentioned above and see if that resolves the problem.
I will attach a document to this e-mail that explains how to go about burping your seahorse’s pouch, including illustrations, so that you can download the document, save it on your computer, and then read through the information as soon as possible.
In addition, if you go to YouTube and search for “releasing gas from your seahorse’s pouch” or something similar, you will find a number of video clips showing exactly how to perform this procedure, which will make it easier for you to resolve this problem.
I will also attach a copy of Will Wooten’s compatibility guide to this e-mail so that you can download it and get a better idea of the live corals that are safe for seahorses and which corals you must avoid in a tank that will house seahorses.
Pete Giwojna, Ocean Rider Tech Support