Re:disease question

Dear Pat:

I am very sorry to hear that the original pair of seahorses have succumbed. All my condolences on your loss!

It sounds like the fin rot had already progressed to the point where the seahorses could no longer be saved. Once the infection works its way all the way down the fan, exposing the fin rays and invading the underlying musculature, antibiotics are no longer effective. At that point, the infection can become systemic and spread to other parts of the body. It sounds like the tails of your seahorses were also being attacked and the "seizures" you describe are indicative of septicemia and problems with major organ failure.

As I mentioned, fin rot is not normally highly contagious. If you wanted to treat the whole aquarium prophylactically to be on the safe side, you would need to use a potent broad-spectrum antibiotic, which would have the unfortunate side effect of killing the nitrifying bacteria and severely impairing your biological filtration. The aquarium would then very likely have to be recycled as a result, and the subsequent ammonia/nitrite spikes would probably cause more problems than the prophylactic antibiotic therapy would help prevent. Let’s avoid that, if possible, Pat.

Rather than treating the main tank with antibiotics, I would concentrate on maintaining optimum water quality (a water change is advisable), holding the water temperature stable between 72°F-75°F, and continuing to feed the seahorses Vibrance-enriched frozen Mysis. Both Vibrance formulations now include beta-glucan as a primary ingredient. The beta-glucan is a powerful immunostimulant that will help the rest of your seahorses fight off infections and remain healthy.

In addition, if you refer to my earlier post to Suzanne titled "Re: Sick seahorse — please help," there is a good discussion of the sort of factors that are often associated with bacterial infections and other disease problems, as well as some of the measures you can take to help prevent them in the future. It includes suggestions for rehabbing your main tank after an outbreak of disease. You can find it at the following link:

Click here: OceanRider : Message: Re: Sick seahorse-please help! <http://groups.yahoo.com/group/OceanRider/message/9573&gt;

In your case, Pat, I suspect the fin rot may have resulted from stress due to overcrowding, and now that the affected seahorses are gone, the cause of that stress may well have been relieved. Just keep the aquarium at its present stocking density and hopefully all will go well.

Aside from maintaining optimum water quality and keeping your seahorses stress-free, Pat, one other preventative measure you might consider is to install an ultraviolet sterilizer on your seahorse tank, as discussed below:

Ultraviolet Sterilizers.

Although it does not improve water quality to nearly the same degree as an ozonizer used in conjunction with a protein skimmer, UV radiation in the proper range (295-400 nanometers) is known to help oxidize phosphates, metabolites, organic molecules and nitrogenous compounds through the incidental production of ozone (Fenner, 2003a).

The primary benefits UV sterilization provides, however, are disease reduction and the reduction of nuisance algae. Ultraviolet radiation can be very effective in reducing free-floating algae, bacteria and microbes in general, certain parasites while in the free-swimming stages of development, and other suspended microscopic organisms (Fenner, 2003a). Seahorses are prone to a number of serious bacterial problems such as Vibriosis, and a properly installed and maintained UV sterilizer can be invaluable in reducing the incidence and spread of such infections. When properly used, UV sterilization can reduce microbial levels in the aquarium to the low levels normally found in the wild or below (Fenner, 2003a).

For best results, the UV sterilizer must be properly sized, operated, and maintained. In order to provide a good kill rate per pass, the effective dwell time (the length of time the water is exposed to UV radiation while passing through the sterilizer) should be maintained at or above roughly twenty gallons per hour flow per watt of UV (Fenner, 2003a). This sounds complicated, but selecting the right sterilizer for your needs is actually very easy. Every manufacturer provides guidelines to help the hobbyist choose a unit and a pump that provide the proper wattage, flow rate and exposure time for any given application.

To assure efficient transmission of the proper wavelengths, sleeves (i.e., the quartz jacket that shields the lamp) must be kept clean and UV bulbs must be replaced at regular intervals. Equally important, the aquarium water should be filtered before it passes through the sterilizer. For maximum efficiency, make the UV sterilizer the final component of an in-line filtration system, so that the water has already passed through your mechanical, biological and chemical filtration media before it flows through the sterilizer (Fenner, 2003a). Do not operate your UV sterilizer during the break-in period when a new aquarium is being cycled and the biological filtration is becoming established. It is counterproductive to reduce microbe levels and nutrient levels when the aquarium is cycling.

Ultraviolet sterilizers are not necessary for maintaining seahorses, but nowadays I would not attempt to keep wild-caught seahorses without one. Hardy, disease-resistant farmed-raised seahorses can do just fine without them, and reefers often frown on UV because it reduces the population of microscopic planktonic organisms filter-feeding invertebrates require. But in my opinion a UV sterilizer makes a very useful addition to the filtration system of the average seahorse setup. The fish farms and aquaculture facilities that raise captive-bred seahorses employ UV radiation in their nurseries and grow-out tanks, and there is no reason the home hobbyist should not take advantage of this technology as well.

Those are my thoughts on the matter, Pat. Best of luck rehabbing the main tank and restoring things to normal.

Respectfully,
Pete Giwojna