Re:Query on floating Seahorse

Dear Lisa:

I am sorry to hear about the problems that your pregnant male has developed. He is not just a strange male that enjoys being upside down during his pregnancy — he is in serious trouble and your instincts to treat him for GBD were quite correct. It is very stressful for seahorses when they develop positive buoyancy to the extent that they are floating helplessly at the surface, unable to swim normally or feed themselves, bobbing around uncontrollably at the mercy of the water jets and currents. He is doomed to a slow death from starvation or complications due to gas bubble syndrome if you are unable to resolve the problem.

So you certainly did the right thing in attempting to release the gas from your pregnant male’s pouch. Because of the placenta-like changes that take place in their heavily vascularized brood pouch during pregnancy, gravid males face an increased risk from pouch emphysema and other forms of gas bubble syndrome. It is entirely possible for a male to be both pregnant and to have gas building up within his brood pouch at the same time. Were any gas bubbles released when you attempted to evacuate the gas from his pouch, Lisa, or were the eggs all that was expelled?

Your stallion may still have gas trapped within his brood pouch and I suggest that you attempt to extract the gas again, but this time I would recommend performing a needle aspiration, as explained below.

Don’t worry that your efforts to evacuate the gas from his pouch may have injured your male or caused any irreparable damage. I can assure you that your efforts in that regard have not ruined your male for breeding or caused him any permanent harm, Lisa. For instance, releasing the air or gas from a tiny dwarf seahorse male is much more difficult than it is for the larger seahorses, and sometimes requires extraordinary measures to accomplish. Here is an account of one such case in which Kirk Strawn — the leading expert on Hippocampus zosterae in the wild — had to evacuate the air from a pregnant dwarf seahorse several times during the course of its pregnancy:

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Herald and Rakowicz (1951) found bubbles to occur in the large seahorses, Hippocampus hudsonius punctatus, as the result of gas given off by decaying young remaining in the pouch after delivery. They recommended removing the bubble by inserting a needle into the opening of the pouch after delivery. This is a more difficult operation on the little dwarfs. It is more easily accomplished either during courtship or following the delivery of young — at which times the opening to the pouch is dilated. Inserting a needle through the entrance of the pouch does not ruin a male for future breeding. A male kept away from females from February until June had bubbles removed on three occasions by puncturing the side of the pouch with a needle and squeezing out the bubble. (Males go through the motions of courtship and may pick up bubbles even if no females are present.) On June seventh he was placed with a ripe, freshly caught female. On the seventeenth I cut a slit in the side of the pouch and removed a bubble and two partly formed babies. By the twentieth [3 days later] the slit was healed over, and he had another air bubble. On the 23rd I partially removed this bubble by forcing a needle through the entrance of the pouch. On the 25th [2 days later] yolk came out when the needle was inserted. On July 5th he gave birth to a large brood after which a bubble was squeezed out of the dilated opening of the pouch without the aid of a needle. The next day he sucked in another bubble while courting. Although removing bubbles does not permanently damage the fish, it is much easier to put a fence, such as a cylinder of plastic screen, around the air stone and its rising stream of bubbles.
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Note that in this episode, Strawn had to perform needle aspirations on his pregnant male multiple times in addition to eventually performing surgery and cutting open the side of the pouch on one occasion, Lisa. Yet even after all of these traumatic events, some of which resulted in yolk or embryonic young being released along with the air, the male still went on to deliver a large brood normally at the appointed time afterwards. So you needn’t be concerned that your efforts to evacuate the gas from your stallion’s pouch are causing him injury or damage, or necessarily dooming any fertile eggs he may still be..

You must release the gas that is bloating his pouch and causing positive buoyancy to provide him with some relief, and I would suggest performing a needle aspiration this time and/or treating your male with Diamox (the tablet form of acetazolamide) as soon as possible. Removing any gas that is build up via a needle aspiration will have a negative impact on very few of the developing young as compared to attempting to manually evacuate the gas. Here are the basic instructions for extracting the gas build up using a needle aspiration:

Needle Aspirations.

It is also very practical to aspirate air from a bloated pouch using a small hypodermic needle and a syringe. The pouch can easily be penetrated from side and is not harmed by the entrance of the needle. It causes the seahorse surprisingly little discomfort and is often less traumatic that massaging the pouch and other methods for evacuating gas. It is a quick and effective technique and is often easier on the seahorse keeper and his patient than other approaches.

Remember, when you perform a needle aspiration, you are not penetrating the seahorse’s stomach, but rather the brood pouch that is slung beneath its belly at the base of its tail.

You cannot release the gas that has built up in your male’s pouch simply by perforating the side of his pouch with a small needle. That’s not what the term "needle aspiration" means. Rather, you need a hypodermic needle and syringe in order to perform a needle aspiration. You must first depress the plunger on the hypodermic syringe to empty all of the air out of the barrel of the syringe, and then carefully insert the hypodermic needle into the side of the pouch, just far enough to penetrate into the central cavity of the pouch, and then gradually withdraw the plunger again, which will extract the gas from that area of the pouch.

You may need to perform this procedure twice, once from the left-hand side of the pouch and once from the right-hand side of the pouch, since male seahorses in breeding condition develop an septum or internal membrane that divides their pouches roughly into left and right hemispheres. So you may need to aspirate air from the left side of the pouch, and then repeat the procedure with your hypodermic needle on the right side of the pouch in order to remove all of the trapped gas from your stallion’s marsupium. But do not penetrate the pouch of your male with a hypodermic needle more than that; if aspirating the gas once from each side of the pouch is not sufficient to deflate the pouch and eliminate the problem with positive buoyancy, then you will need to pursue another form of treatment instead.

You may also need to administer Diamox as a series of baths to counteract this problem with positive buoyancy, Lisa. It’s possible that the positive buoyancy in your male is not caused by gas building up within his brood pouch, but rather by gas building up within his abdominal cavity (i.e., internal GBS) or by an overinflated swim bladder, which are other forms of gas bubble syndrome. Diamox (the tablet form of acetazolamide) is often needed to resolve such cases.

The recommended dosage is 250 mg of Diamox per 10 gallons with a 100% water change daily, after which the treatment tank is retreated with the Diamox at the dosage indicated above (Dr. Martin Belli, pers. com.). Continue these daily treatments and water changes for up to 7-10 days for best results (Dr. Martin Belli, pers. com.).

The Diamox baths should be administered in a hospital ward or quarantine tank. Diamox 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 seahorses.

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 hospital tank, minus the residue, of course, at the recommended dosage:

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 Diamox at the same dosage 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 up to 7-10 treatments have been given. About 24 hours after the 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.

As with Diamox pouch flushes, one of the side affects of acetazolamide baths is loss of appetite. Try to keep the affected seahorse eating by plying it with its favorite live foods during and after treatment, until it has fully recovered.

The seahorse usually show improvement within three days. Dr. Martin Belli reports they nearly 100% success rate when this treatment regimen is followed for 7-10 days, and most cases clear up in less than a week.

Please get back to me right away and let me know if you are able to release any gas bubbles from your male’s pouch, Lisa, or if the needle aspiration(s) proves successful and returns or male to be neutral buoyancy again. If not, there are alternative treatments you can consider such as manually aspirating some of the air from the swim bladder, reducing the specific gravity and water temperature in your seahorse tank, and pressurizing the male at depth. I will be happy to provide you with instructions for these other methods of treatment if necessary. In the meantime, I suggest lining up a supply of Diamox and performing a needle aspiration of the pouch ASAP.

Respectfully,
Pete Giwojna