his disease is usually called “White Spot Disease”, since the parasite can be seen with the naked eye as one mm diameter white spots distributed over the body and fins when it is in the trophozoite stage, the feeding phase of the parasite. It should be noted that, despite appearances, the parasites actually sit within the epidermis, and not on the surface. This makes treatment more complicated, as a topical approach will not easily work.
...
Deposition of aluminium in gills leads to chloride cell necrosis or at lower levels, to inhibition of the enzymes carbonic anhydrase and/or gill NA+, K+ – ATPase (NKA), required for seawater tolerance. Such changes impair osmoregulatory capacity and cause physiological stress due to disruption of gas and ion transport, altered blood chemistry and hormonal imbalance.
...
Saprolegnia often presents as a secondary infection that is diagnosed by the appearance of white or grey cotton-like tufts that, when out of water, have a somewhat mucoid appearance. Typical disease signs are visible circular or crescent-shaped, cotton-wool like, white or grey patches of filamentous mycelia on the fish skin. The lesions appear mainly around the head and the caudal, adipose and anal fins. Lesions may spread over the body until adjacent lesions coalesce.
...
Tenacibaculosis is a serious bacterial disease affecting a great variety of marine fish, especially those species under culture conditions, causing necrotic lesions on the body. Gross pathological signs vary according to the species and age of fish involved. Characteristic clinical signs are ulcerative skin lesions, mouth erosion and ulceration, and fraying of fins and tail. In general, it is mainly a superficial infection, but some isolates are highly toxigenic, and systemic disease can therefore result, involving different internal organs. Several species of Tenacibaculum can be...
Tenacibaculosis is primarily a skin infection causing ulcerative dermatitis in a range of commercially important species worldwide. Three species belonging to the genus Tenacibaculum have been associated with the disease: T. dicentrarchi, T. finnmarkense, and T. maritimum. These bacteria are all Gram-negative and filamentous. In marine fish, the most common isolate is T. maritimum. There is variation in the external pathological signs of the disease, depending on the species and age of the fish involved. Different names have been used for this usually ulcerative dermatitis; they include salt water columnaris...
