New Seahorse Help!!!

Dear JR:

Congratulations on your new arrivals!

The new male that is spending a lot of time at the top of the tank and struggling to swim down to the bottom has developed a problem with positive buoyancy (i.e., the tendency to float).

Positive buoyancy can result from a number of different causes, JR. 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.

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 gas bubble syndrome. When that happens, the pouch of the male will become bloated as gas builds up inside it. Does the pouch of your new male Mustang appear to be swollen or distended, JR?

If not, if the pouch of the male Mustang that is having the positive buoyancy problems is similar in size and appearance to the pouch of the other new male that is doing well, then the problem is most likely due to a hyperinflated swimbladder. Your initial post does not mention anything about the male’s pouch being enlarged or swollen at all.

That makes me think that your new male is most likely experiencing buoyancy problems due to a hyperinflated gas bladder (i.e., swimbladder), which is a problem that can often correct itself over a period of several days. There is a special oval-shaped area on the surface of the swimbladder that is heavily vascularized and reabsorbs excess gas, but this is a relatively slow process that takes a while to accomplish, and certain disease processes can prevent that from occurring.

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. The heavily vascularized oval of the gas bladder will gradually reabsorb excess gas to restore neutral buoyancy. And if the swimbladder is underinflated, the seahorse has negative buoyancy and must swim hard in order to avoid sinking. In that case, the gas gland will secrete additional gas in order to further inflate the swimbladder and restore neutral buoyancy again. But these processes take a little time to work, and sometimes disease processes prevent the swimbladder from regulating itself properly.

If your new male is still able to hunt and feed despite the problems caused by positive buoyancy, JR, even if you must be target fed (which is a good idea with new arrivals, in any case) in order to do so, then you can afford to wait a few days to see if the problem resolves itself, and that is often the best course of action, particularly with new arrivals. If you’re new male is not able to resolve the hyperinflated gas bladder on his own, there are a few treatment options you can consider, but for now the best thing you can do is just to observe him and wait to see if he will be able to reabsorb the excess gas on his own.

It will be helpful if you can guide your new male to a convenient perch near the bottom of the tank so he can cling to it with this tail, which will assure that your weak stallion does not have to waste energy swimming against the tendency to float, JR. And it may also be helpful if you can adjust the output from the aquarium filter(s) so that the water flow is roiling the surface of the aquarium. This will promote more efficient gas exchange at the air/water interface, which is where carbon dioxide is off gassed and fresh oxygen enters the aquarium water. That will help the aquarium to maintain high levels of oxygenation and dissolved oxygen, and low levels of dissolved CO2, which will help the weak female to breathe more easily.

If the output for the filter cannot be adjusted so that it roils the surface of the aquarium, then you can accomplish the same thing by anchoring an ordinary airstone a short distance beneath the surface of the aquarium so that the bubbles from the airstone can provide more efficient surface agitation.

On the other hand, JR, if the pouch of your new male with the positive buoyancy is noticeably bloated or distended, then the problem is no doubt due to a buildup of gas within the marsupium. In that event, manually releasing or evacuating the excess gas from the broodpouch will provide the seahorse with quick relief. There are a number of different ways that this can be accomplished, so please let me know if the male’s pouch appears to be swollen and enlarged, and I will provide you with detailed instructions explaining how to release this gas and resolve the problem.

Best of luck with your new ponies, JR!

Respectfully,
Pete Giwojna, Ocean Rider Tech Support