In this section of the articles library you will find information about the reasons behind different saltwater fish diseases and how to avoid them, treat them and – if possible – cure them. Some of the most commonly occurring fish diseases in saltwater aquariums are Marine Velvet, Marine White Spot Disease, Brooklynella hostilis andUronema marinum.
Marine Velvet is cause by a saltwater parasite; Amylodinium. Amylodinium will typically attach the gills of the fish, but can also infect the skin. If you suspect that your fish has been infected with Marine Velvet, you can use a strong flashlight and light up the top of the fish when the rest of the room is darkened. If the gills and the sides of the fish that receives indirect lighting look velvet or as if dusted with gold, you should treat the fish for Amylodinium.
Marine White Spot Disease is also known as marine Ich and marine Ick. The symptoms are very similar to those displayed by fish infected with freshwater Ich, but marine Ich is not caused by the same parasite a freshwater White Spot Disease (Ichthyophthirius). Marine White Spot Disease is caused by Cryptocaryon, a saltwater parasite. A marine fish that successfully combats an attack from Cryptocaryon can develop immunity that lasts up to 6 months.
Brooklynella hostilis is a ciliated protozoan that lives in saltwater. An infected fish can become sluggish and will often take food into its mouth and spit it out. If Brooklynella hostilis colonizes the gills, the fish will experience breathing problems. Smear test from the gills is used to diagnose a Brooklynella hostilis infestation. You can also notice signs of Brooklynella hostilis on the skin of the fish. In the beginning, small areas will look faded and listless. As the infestation becomes more severe, these areas will grow and spread outwardly. The skin will become more and more damaged. Brooklynella hostilis is sometimes called"Clownfish Disease", but the parasite can infect a wide range of marine fish species.
Uronema marinum is a saltwater parasite that can grow rapidly in aquariums where the water quality is poor due to large amounts of organic matter. Be extra careful with the levels of nitrate and phosphate if you are having problems with Uronema marinum. The Yellow Tang is especially prone to Uronema marinum infestations, but the parasite is capable of infecting a wide range of fish species, including all the other Tangs. Seahorses can also suffer from Uronema marinum attacks. In infected fish will begin to scrub itself against rough surfaces in the aquarium. It will sooner or later become extremely exhausted and rise to the surface where it can gasp for air. Its colors will usually fade and the skin will eventually begin to die. The skin will look slimy, hemorrhagic lesions will manifest and the eyes of the fish will usually turn clouded. If the Uronema marinum infestation progresses, the fish can become completely blind. Deaths are also common and recent research have shown that Uronema marinum do not only infect the skin and gills of the fish, but the kidney and brain as well.