Re:ill sunburst

Pete Giwojna

Dear hobbyist:

Your water chemistry looks fine but the areas of pale discoloration on the left flank of the seahorse suggest an infection of some sort. At this point, it’s impossible to say if the discoloration is due to a fungal infection and/or bacterial skin infection, possibly the initial stages of white patch disease (marine columnaris — Cytophaga or Myxobacteria spp.) or the early stages of marine ulcer disease (Pseudomonas or Vibrio spp.), or if it’s the result of a protozoan parasite attacking the skin, and I am therefore going to recommend that you treat the seahorse in isolation with antibacterial agents in conjunction with a series of formalin baths.

It will also be helpful if you can drop the water temperature in the hospital tank during the course of the treatments. Gradually reducing the water temperature will slow the metabolism and reproductive rate of the pathogens, making them easier to control, and the virulence of many bacterial infections is markedly reduced at lower temperatures (Giwojna, Nov. 2003).

As I mentioned, there are a number of parasitic infections that can easily be mistaken for for bacterial and/or fungal infections in the early stages. For example, Brooklynella, Costia and Uronema parasites all cause cloudiness or turbidity of the skin accompanied by heavy mucous production in their initial stages, which are similar to the light areas of discoloration on the side of your seahorse (Giwojna, Nov. 2003). In their later stages, these parasitic infections result in respiratory distress and ulcers or open sores that are very like the symptoms of white patch disease or marine ulcer disease when the enzymes the bacteria produce erode away the skin and the gills are involved (Giwojna, Nov. 2003). Parasitic infections are often followed by secondary bacterial/fungal infections, and such parasites are one of the stressors that can result in a bacterial or fungal infection. This can make it difficult to determine whether you are dealing with bacteria, fungus, a parasite problem, or a mixed infection (Giwojna, Nov. 2003).

But that really doesn’t matter because the treatment regimen we are discussing should be effective whether bacteria, fungus, protozoan parasites, or all of the above are involved. If you treat your seahorse with a potent combination of antibiotics, gradually reduce the water temperature in your hospital tank to as low as 68°F if possible, and administer series of formalin baths (see instructions below), that should give you the best chance of resolving this problem.

The antibiotics I recommend for this are nifurpirinol (the active ingredient in Furanase) and neomycin sulfate, if you have them on hand or can obtain them from your LFS. If not, then I suggest you try Neo3, a concentrated formulation of neomycin combined with sulfa compounds, which is available online from the following web site:

Click here: <<>&gt;


Neo3 has also been difficult to obtain lately, and if that’s the case, then kanamycin sulfate or neomycin sulfate combined with triple sulfa is a suitable substitute. Kanamycin and/or neomycin sulfate can safely be combined with various sulfa compounds. One that seems to work particularly well is combining neomycin sulfate with triple sulfa. You may be able to get neomycin sulfate and triple sulfa compound at a well-stock LFS. If not, you can obtain both neomycin sulfate powder and triple sulfa powder from National Aquarium Pharmaceuticals. You can order them online at the following site:

Formalin baths used in conjunction with these antibiotics will help eliminate any ectoparasites or secondary fungal infections that may be involved. Formalin is basically a 37% solution of formaldehyde and water. It is a potent external fungicide, external protozoacide, and antiparasitic, and seahorse keepers commonly use formalin to cleanse new arrivals of ectoparasites during quarantine. Formalin (HCHO) is thus an effective medication for eradicating external parasites, treating fungal lesions, and reducing the swelling from such infections. As such, formalin baths combined with the broad-spectrum antibiotics mentioned above should be very effective in clearing up a bacterial lesion.

Many commercial formalin products are readily available to hobbyists, such as Kordon’s Formalin 3, Formalin-F sold by Natchez Animal Supply, and Paracide-F, sold by Argent Chemical Laboratories. Or whatever brand of formalin is available at your fish store should work fine.

A formalin bath simply involves immersing the seahorse in a container of saltwater which contains the proper dosage of formalin for a period of 30-60 minutes before transferring it to your hospital tank. Include a hitching post of some sort in the container and follow these instructions: place the fish in a three-gallon bucket or a similar clean, inert container containing precisely one gallon of siphoned, aerated tank water. Medicate the bucket of water with with the appropriate amount of formalin for a concentrated bath according to the directions on the label. Place an airstone in the bucket and leave the fish in the bath for up to 60 minutes. If at any time the fish becomes listless, exhausted or loses its balance, immediately place the fish in clean, untreated water in your hospital tank.

I want you to be aware of these precautions when administering the formalin bath:

Formalin has limited shelf life and degrades to the highly toxic substance paraformaldehyde (identified as a white precipitate on the bottom of the solution); avoid using any formalin product which has such a precipitate at the bottom of the bottle.

Formalin basically consumes oxygen so vigorous aeration must be provided during treatment.

Time the bath closely and never exceed one hour of chemical exposure at this concentration.

Observe the seahorse closely during the bath at all times, and it show signs of distress before the allotted time has elapsed, remove it from the treatment immediately.

If you can obtain Formalin 3 from Kordon at your LFS, these are the instructions you should follow for your formalin dip:


(a) To a clean, non-metallic container (i.e., a plastic bucket), add one or more gallons of fresh tap water treated with Kordon’s AmQuel . For marine fish use freshly prepared saltwater adjusted to the same specific gravity (or salinity) as in the original tank. Make sure the temperature in the container is identical to that in the aquarium

(b) Add 1 teaspoons of Formalin·3. This produces a concentration of 100 ppm. formaldehyde.

(c) Agitate the solution with an airstone and adjust for a moderately strong flow of air.

(d) Remove the fishes to be treated and deposit them in the container for a treatment period of not more than 50 minutes. Immediately after the treatment period, or if signs of distress are noted, remove the fishes to a previously prepared recovery tank. The fishes may be returned to their original tank, but the presence of the original disease-causing agents in the tank water may result in a reoccurrence of the disease condition.

(e) Observe recovering fishes. Make sure that tankmates do not molest them during recovery.

(f) Repeat treatment as needed, every week. Each treatment is very stressful to the treated fishes. Do not reuse the dip solution.

For additional information on treating fishes with Formalin 3 by Kordon, see the following web page:

Click here: KPD-54 Formalin-3


If you get another brand of formalin, just follow the instructions that it comes with for a concentrated bath or dip (not prolonged immersion or a long-term bath).

Be sure to observe the following precautions when handling your seahorses to apply the Biobandage or to administer the formalin baths:

Handling Seahorses

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.

In short, I suggest that you treat the affected seahorse in isolation with broad-spectrum antibiotics and formalin baths, as discussed above, and gradually lower the water temperature in your hospital tank. It is possible that this regimen of treatment may also have a positive effect on the weak snick that has been troubling your seahorse, since it will help to eliminate any parasites or secondary infections that could be affecting your seahorse’s hyoid bone feeding mechanism.

Best of luck restoring your seahorse to good health.


Pete Giwojna

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