Vibrio infections… The Red Pest

By Steve Skinner

Much like Lymphocystis, more common Vibriosis conditions are treatable in much the same way. In most all cases it is due to the abundance of nutrient in the water column. Usually first detected as red streaking on the body of the fish or near fins. Vibrio conditions can lead to greater health concerns but is often not life threatening when dealt with quickly and efficiently. In some instances, the same red “streaks” can be found in fish where proper pH is not correctly maintained regularly falling below 8.0 as the norm instead of the exception.

In both cases (Vibrio or pH) with regards to milder cases, water changes with well aged and aerated saltwater will fix both problems simultaneously. Steps should be taken as well to preventing a re-occurrence. Proper water maintenance, not overfeeding or overstocking using the same guidelines as linked to in the Lymphocystis article. Immediate quarantining is usually not required when caught early enough. Although other fish within the system are susceptible, an otherwise healthy and properly fed ecosystem will help the fish to fight off the infection themselves. Spreading from one fish to another is not commonly seen unless in very poor conditions, a virulent strain or pH related.

In hard to treat cases where repeated water changes have made no improvement or the lesions are becoming more apparent, treating with a gram negative antibiotic in a proper quarantine set up will be needed. Never treat fish with antibiotics in the main display. Maracyn II® at double the dose each day for seven days should see quick results. As before, soaking the foods in the medication will improve results. Nitrofurazone based medications can also be used where Maracyn II® is unavailable.

If determined the cause to be pH related, the more common contributors will be poor aeration, low GPH, the use of solid lids on the aquarium, excess ambient CO2 (open a window) and as usual, overfeeding and/or overstocking. pH issues are more commonly environmental than chemical so amending the conditions that contribute to low pH will typically correct the problem. In extreme cases where pH continues to be an issue, alkalinity should be carefully monitored and maintained at a higher level. Usually 3.5-4 mEq/l will aid in preventing larger dangerous swings affecting the health of fish and other organisms. Altering the chemistry should however be a last resort if alkalinity is otherwise in the proper NSW range of 1.5-3/mEq/l. Attempting to rely on chemical additions as a means of controlling pH will not be very productive in the long term.

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