Not sure if this is ich or not. Came home from a 5 day trip, fish was being fed from auto feeder and was checked on daily by house sitter. Fish appears to be acting normal and eating but has a strange foggy film on upper portion of body. Any ideas what this could be? Tank has been running for approximately 5 weeks and has a large diatom outbreak right now. Any suggestions on how to resolve this are appreciated.
It can be difficult to tell Brooklynella apart from marine ich. In this case, although I can see discrete spots on the fish, I would lean towards Brooklynella based on your description. That can be difficult to treat. here is an excerpt that I wrote up about it:
Brooklynellosis
Cause
Brooklynellosis is caused by a ciliated protozoan, Brooklynella hostilis. It commonly affects newly acquired wild-caught clownfish, thus its common name “clownfish disease.” Entire shipments of wild-caught clownfish have been lost to this infection. It is also commonly seen in marine angelfish and Anthias and sometimes in butterflyfish and tangs. The life cycle is direct, there is no resting stage.
Symptoms
Aquarists often miss the early symptoms of this malady in their fish, so by the time it’s identified, it’s often too late to easily save the specimen. The first signs of this disease may be limited to slightly folded fins combined with lethargy. Soon, skin mucus production increases, as does the fish’s breathing rate. The fish will then lose color, stop feeding, and hang in one location, with death following in a matter of hours to days.
Uronema often has similar symptoms, but a reddish underlying lesion is usually associated with that disease. Bacterial infections can produce similarly cloudy skin, but they typically do not result in rapid breathing. End-stage Cryptocaryon can sometimes be mistaken for Brooklynellosis, as well. Positive identification requires microscopic examination of a skin scraping. Look for medium-sized, barely motile protozoans that are ventrally flattened with a slightly domed dorsal side and have cilia mostly at one end.
Treatment
Few treatments are effective against Brooklynellosis, although two options include a 14-day chloroquine treatment at 15 mg/l or daily formalin dips at 150-167 ppm for 45 minutes with good aeration. The effectiveness of dips is vastly improved if the fish is then moved to a non-infected aquarium. Reducing the specific gravity of the treatment tank may assist the fish in balancing the electrolytes lost due to skin and gill damage. A target specific gravity of 1.018 should be maintained during treatment. Some aquarists have reported success using a proprietary product that contains a low dose of formalin along with acriflavine. Normal level copper treatments do not work for this disease.
Prevention
Acquiring captive-raised clownfish as opposed to wild-caught ones is a good way to help prevent outbreaks of this disease. However, tank raised clownfish that have been mixed with infected wild caught clownfish through the supply chain are equally at risk. Brooklynellosis is much easier to manage in a quarantine aquarium than in a main display tank.
Jay
