Re:Female H. Barbori-sick?

Pete Giwojna

Dear Jana:

I’m very sorry to hear that your female Hippocampus barbouri is having a problem. The type of behavior you describe — laying horizontally on the bottom, attempting to proper herself up against objects, and the inability to assume her normal upright posture when perched to a hitching post — could be either an indication of generalized weakness or it could be due to negative buoyancy as the result of swim bladder disease or a buildup of fluid accumulating within her coelomic cavity.

Due to the sudden onset of the problem, I suspect the problem may be due to a swim bladder disorder. It just seems to me that it would take more time for your female Barb to become debilitated to the point that she was unable to hold herself upright, or for a sufficient quantity of fluid to build up in her abdomen so that it weighed her down so much she could no longer maintain her normal upright posture, and I think you would have noticed some previous symptoms in those cases. So I’m going to rule out generalized weakness and ascites (i.e., fluid build up) for the time being, and concentrate on a malfunction of the swimbladder instead.

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. It will have a whitish to silvery appearance and is a simple, single-chambered sac that begins at the bend in the neck and extends to about 1/3 of the length of the coelomic cavity (Bull and Mitchell, 2002).

When the swim bladder is inflated with just the right amount of gas, the seahorse achieves neutral buoyancy, which just means that if neither tends to rise or sink. It is thus weightless in the water, with the buoyancy from its gas bladder exactly canceling out the pull of gravity. This facilitates swimming and makes holding its body upright effortless.

But a number of things can disrupt the normal functioning of the gas bladder and the gas gland that inflates it, resulting in either too little or too much gas being secreted into the swimbladder. When too much gas is secreted into the swimbladder the seahorse becomes too buoyant. Hyperinflation of the swimbladder thus results in positive buoyancy and the tendency to float. Likewise, if too little gas is secreted into the swimbladder, exactly the opposite occurs in the seahorse becomes too heavy. Under inflating the gas bladder therefore results in negative buoyancy and the tendency to sink.

I suspect your female Barb is suffering from an underinflated swim bladder or gas bladder, Jana. The resulting negative buoyancy makes it difficult for the armor-plated seahorse to swim normally, rise from the bottom, or even hold itself erect. An underinflated swim bladder is sometimes a problem a seahorse can correct on its own, as more gas is gradually secreted into the swim bladder from the gas gland. However, this is a gradual process and may take days to accomplish.

But an underinflated gas bladder can also result from infection, and I have seen several cases of swim bladder disease that were associated with internal parasites, which sometimes also contribute to generalized weakness, so I think it it would be prudent to treat your seahorses with a good antiparasitic that is effective against internal parasites, such as metronidazole or praziquantel.

Metronidazole is an antibiotic with antiprotozoal properties that is very effective in eradicating internal parasites in general and intestinal flagellates in particular (Kaptur, 2004). It is ideal for this because it is rapidly absorbed from the GI tract, has anti-inflammatory effects in the bowel, and was designed specifically to treat protozoal infections and anaerobic bacterial infections by disrupting their DNA (Kaptur, 2004).

If the seahorse is still eating, administering the metronidazole orally via gut-loaded shrimp is often extremely effective (Giwojna, Dec. 2003). Keep the seahorses on a strict diet of gut-loaded brine shrimp for 5-10 days. When administered properly, metronidazole is wonderfully effective at eliminating intestinal parasites, and there should be signs of improvement within 3 days of treatment (Kaptur, 2004).

Gutloading simply means to fill live shrimp up with medication by feeding them food that’s been soaked in the desired medication. Once the feeder shrimp are full of the medicated food — that is, their guts are loaded with it — they are immediately fed to the seahorses, which thus consume the medication along with the shrimp. It’s a neat way to trick seahorses into taking their medicine, just as our moms used to do when were little, crushing up pills in a spoonful of jelly or jam. Another term for gutloading is bioencapsulation, since the medication is neatly contained within a living organism rather than a capsule. Gutloading allows the seahorses to be treated in their main tank, where they are completely at home, surrounded by their tankmates and the rest of the herd, and is thus a very stress-free form of treatment.

There are a number of ways to gutload shrimp, but many hobbyists find it easiest to gutload adult brine shrimp with metronidazole as described below. It is impossible to determine precisely what dosage of medication each individual fish ingests when gutloading, but metronidazole is a very, very safe drug and you cannot overdose a seahorse using this method of treatment. Feeding each seahorse its fill of shrimp gut-loaded with
metronidazole for 5-10 days assures that they receive an effective dose of the medication.

Adult brine shrimp can gut-loaded or bio-encapsulated as follows. To medicate the brine shrimp, dissolve approximately 100 mg of metronidazole per liter or about 400 mg per gallon of water and soak the shrimp in the resulting freshwater solution. If the metronidazole you are using comes in liquid or capsule form, you can use it as is. But if the metronidazole is in tablet form, be sure to crush it into a very fine powder (you may have to use a household blender to get it fine enough) and dissolve it in freshwater at the dosage suggested above. Soak the adult shrimp in freshwater treated with the antibiotic for 15-30 minutes and then feed the medicated shrimp to your seahorses immediately. (Don’t let your pumps and filters "eat" all the brine shrimp!)

The brine shrimp are soaked in freshwater, not saltwater, because in theory the increased osmotic pressure of the freshwater helps the antibiotic solution move into their bodies via osmosis. But in fact nobody knows for sure whether the antibiotic is diffusing into the brine shrimp or they are ingesting it in very fine particles (brine shrimp are filter feeders and will take in whatever is suspended in the water with them) or whether the brine shrimp merely become coated with the antibiotic while they are soaking in it. But that’s not important — all that really matters is that gut-loading adult brine shrimp with medications this way is effective.

Keep the seahorses on a strict diet of such medicated brine shrimp throughout the treatment period to get as much of the antibiotic into the seahorses as possible, and mix up a new batch of medicated freshwater to soak the brine shrimp in for each feeding.

You should be able to obtain a medication at your local fish store that has metronidazole as all as its primary ingredient, Jana. Administering it to your seahorses via gut-loaded adult brine shrimp is a very safe, gentle treatment, that should not stress your seahorses in any way. If your female H. barbouri’s underinflated swim bladder is due to internal parasites or anaerobic bacteria, the metronidazole should set things right. Or she may be able to reinflate are swimbladder and restore neutral buoyancy on her own over a period of days.

In the meantime, just make sure your pH and dissolved oxygen levels are on the mark, keep your temperature in the comfort zone for H. barbouri, maintain optimum water quality, and feed your seahorses medicated adult brine shrimp for the next several days just as we’ve discussed, Jana. Please give me a quick update regarding her progress in a few days.

Best of luck with your ailing H. barbouri. Here’s hoping she is soon swimming normally, perching properly, and back to her old self again before you know it!

Pete Giwojna

America's Only Seahorse Aqua-Farm and One of Hawaii's Most Popular Attractions

Ocean Rider seahorse farm is a consistent Trip Advisor Certificate of Excellence Award Winner and "Top 10 Things To Do" Kona, Hawaii attraction. Our "Magical Seahorse Tours" are educational and fun for the whole family.

Tour tickets are available for Purchase On-Line. Space is limited and subject to availability.

small seahorse Ocean Rider, Inc. is an Organic Hawaiian-Based Seahorse Aqua-Farm & Aquarium that Follows Strict Good Farming Practices in Raising Seahorses and Other Aquatic Life.

Seahorse Hawaii Foundation

Inspiring ocean awareness by saving the endangered seahorse and sea dragons around the world from extinction through conservation, research, propagation, and education.

Help us save the seahorse and the coral reefs they live in with a tax deductible contribution to the Seahorse Hawaii Foundation. You will be helping to protect and propagate over 25 species of endangered seahorses, sea dragons and friends.

Make A Tax-Deductible Donation Today!

A Different Kind of Farm (Video) »

Ocean Rider Kona Hawaii

Ocean Rider Kona Hawaii
Seahorse Aqua-Farm & Tours

73-4388 Ilikai Place

Kailua Kona, Hawaii 96740

Map & Directions


Contact Ocean Rider

Copyright ©1999-2023
All Rights Reserved | Ocean Rider Inc.

My Online Order Details

Purchase Policy

Site Terms and Conditions