Thanks for getting back to me with the additional information so promptly. Your 55-gallon aquarium is a very good size for a seahorse tank and the system is fully cycled. All of the aquarium parameters are good and a stable water temperature 75°F is well-suited for most tropical seahorses, so you are doing a lot of things right.
It’s good to hear that it was the male sea horse that had been floating. It’s much easier to cure a case of bloated pouch or pouch emphysema then it is to resolve other forms of gas bubble syndrome. And it’s even better to hear that your male is no longer floating — that’s an encouraging sign.
I am more concerned about the spasming than the positive buoyancy at this point, but I am wondering if you could possibly be mistaking a pouch display known as "Pumping" for spasms. When a male is pumping, he bends forward at the waist and then jerks backward vigorously in a maneuver that thrusts his pouch out. This series of contortions has the effect of forcing water in and out of the male’s brood pouch, which is why it’s often referred to as "Pumping," and the procedure is normally performed to cleanse and flush out the pouch in order to prepare it for mating. (However, seahorses will also pump when something is irritating their pouches.)
During these displays the male carries out a series of strenuous pelvic thrusts that pump water in and out all of his pouch and are very similar to the contractions he goes through when giving birth. These pouch displays are performed with great vigor, while the brood pouch is fully inflated with water, and can be quite alarming the first time you see them. It looks almost as if the male is performing abdominal crunches or experiencing severe abdominal cramps. With it’s abdomen grossly distended, the male’s contortions make it look very much as if it’s suffering from a severe bellyache, and to the uninitiated it may look like the seahorse is experiencing seizures, spasms or convulsions, or is in the throes of death.
Males with pouch gas can sometimes eliminate the trapped gas on their own during their vigorous pouch displays in which they inflate their pouches to the fullest and pump water in and out. Just occasionally they can expel pouch gas or trapped air during these displays of "Pumping."
In fact, in the old days, I corresponded with Bart Goedegebuur, a successful seahorse breeder in the Netherlands, about one such incident in which a male H. erectus of his was able to expel the trapped air on its own. Afterwards, Bart noted that: "The releasing of air bubbles out of the horse pouch due to his own actions seems to me very interesting. Because till now I only read that trapped air has to be removed manually because the horse can’t do this himself." It’s obvious that English is Bart’s second language, but he always manages to get his point across nonetheless.
So I am wondering if the spasming you reported may actually be the male pumping out his pouch vigorously, and if perhaps he may have been able to expel at least some of the trapped gas well he was doing so, which may be why he is no longer floating? Do you think that’s possible, Carianne? Does my description of how males pump when they are performing these pouch displays sound like it could be responsible for the spasms that alarmed you?
If so, then things are not nearly as dire as you may have imagined, particularly if your male managed to release the gas that was trapped in his pouch while he was pumping. That may have provided them with some relief from the positive buoyancy and he may be able to swim and eat normally for the time being.
But you should be aware that pouch gas tends to recur and your male may experience more problems with positive buoyancy as more gas builds up in his pouch, so you’ll have to keep a close eye on him for any indications that the problem is returning. This is what to look for, Carianne:
One simple way to determine if the seahorse is struggling with positive buoyancy is to observe him while he is swimming. The first indication of positive buoyancy is a loss of equilibrium. The seahorse’s center of gravity shifts as it becomes more buoyant, 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 is normally obviously swollen and bloated.
So I would like you to gently induce your seahorse to release its grip on its hitching post, Carianne, and then release him at the bottom of your aquarium and observe him closely to see if he can swim normally, in the typical upright swimming posture of Hippocampus, or if he struggles as described above and tends to float back up to the top of the aquarium again. (This will also be a good way to test whether or not you have too much water current or turbulence in your aquarium, by observing if the seahorse is getting blown around by the water flow and has to struggle mightily to fight against the current.)
Here is the proper way to encourage your seahorse to release its grip and to handle it when performing this simple test, Carianne:
I do not like to use an aquarium net to transfer or manipulate seahorses, since their delicate fins and snouts can become entangled in the netting all too easily. I much prefer to transfer the seahorses by hand. Simply wet your hand and fingers (to avoid removing any of the seahorse’s protective slime coat) and scoop the seahorses in your hand. Allow them to curl their tail around your fingers and carefully cup their bodies in your hand to support them while you lift them out of the water. When you gently immerse your hand in the destination tank, the seahorse will release its grip and swim away as though nothing out of the ordinary has happened.
Composed of solid muscle and endowed with extraordinary skeletal support, the prehensile tail is amazingly strong. Indeed, large specimens have a grip like an anaconda, and when a 12-inch ingens or abdominalis wraps its tail around your hand and tightens its hold, its vise-like grip is powerful enough to leave you counting your fingers afterwards!
In fact, it can be quite difficult to remove an attached seahorse from its holdfast without injuring it in the process. Never attempt to forcibly detach a seahorse from its hitching post! When it feels threatened, it’s instinct is to clamp down and hold on all the tighter. When you must dislodge a seahorse from its resting place for any reason, it’s best to use the tickle technique instead. Gently tickling the underside of the tail where it’s wrapped around the object will usually induce the seahorse to release its grip (Abbott, 2003). They don’t seem to like that at all, and will quickly let go to move away to another spot. Once they are swimming, they are easy to handle.
If your new male should develop more problems with positive buoyancy and pouch gas, Carianne, you can provide him with some immediate relief by performing a pouch evacuation or a pouch flush in order to release the gas that is trapped within his pouch. If you look up a previous post on this forum titled "Seahorse floating upsidedown," you’ll find a thorough discussion of this condition explaining why it is potentially dangerous along with detailed instructions for evacuating the gas from his pouch manually or performing a pouch flush to release the trapped gas. Just copy the following URL and paste it in your Web browser and it will take you directly to that discussion and the instructions explaining exactly how you should proceed:
I would ordinarily not expect a seahorse to have problems with the current or water circulation in a long 55-gallon tank that is filtered with undergravels, unless the seahorses in question are very small or very weak. How large are your new seahorses, Carianne? You mentioned that the seahorses were sold to you as Hippocampus kelloggi but that you doubted that identification. What makes you think that your new seahorses are not H. kelloggi after all? Do you have any additional filters or water pumps on the tank that are contributing to the water movement?
Please keep a close eye on your male for any more indications of pouch gas or positive buoyancy, and test his swimming ability as described above, if you are unsure whether he needs help in expelling any more gas that may build up within his pouch. And please do let me know how large your seahorses actually are and, if they are not H. kelloggi, which species of seahorses you think they may be. Once I have the additional information about the size of the seahorses and the equipment on your 55-gallon aquarium, I can provide you with better advice regarding how to manage the water circulation.
Best of luck with your new seahorses, Carianne!