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.
...
We have recently seen a high incidence of cataracts in farmed salmon in several European countries, Canada, and Chile. Salmonids depend on vision for normal feed intake and, not surprisingly, cataracts have been shown to reduce feed conversion efficiency and growth rates, which ultimately raise the cost of rearing fish. Consequently, cataracts can have a significant economic impact on salmonid aquaculture. It is important to note at the outset that “cataracts” is a clinical definition, and their presence does not necessarily mean that changes can...
Infectious salmon anaemia (ISA) is a disease caused by infectious salmon anaemia virus (ISAV), genus Isavirus, family Orthomyxoviridae that affects primarily marine-farmed Atlantic salmon (Salmo salar). Recorded for the first time in 1984 in Norway, it still causes recurrent epidemic outbreaks in Chile. The disease is present in most countries that farm Atlantic salmon: Norway, Scotland, Ireland, Faroe Islands, Canada, USA, and Chile. The virus is adapted to cold-water salmonid fish and has an optimum growth at 15°C. Atlantic salmon is the only species known...
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...
Copper is a significant trace element necessary for the normal growth and metabolism of living organisms. However, if there is overexposure, it can be toxic. Levels of dissolved copper are often increased from anthropogenic origins such as mine washings and direct applications of algicides, molluscicides or antifouling agents. The most toxic form of copper is the cupric ion (Cu2+). Fish and crustacea are 10 to 100 times more sensitive to the toxicity of copper than mammals. For salmonids, the upper recommended limit is < 0.03...
