Comparative susceptibility of two races of Salmo salar (Baltic Lule river and Atlantic Conon river strains) to infection with Gyrodactylus salaris

Diseases of Aquatic Organisms

M. B. Dalgaard¹  C. V. Nielsen¹  K. Buchmann¹ 

关键词: Atlantic salmon;    Salmo salar;    Conon river;    Lule river;    Gyrodactylus salaris;    Susceptibility;    Mucous cells;    Dexamethasone;   

DOI  :  10.3354/dao053173

学科分类：生物科学（综合）

来源: Inter-Research

【 摘 要 】

ABSTRACT: The susceptibility of various races of salmonids towards infections with the skin parasitic monogenean Gyrodactylus salaris Malmberg, 1957, differs markedly. Norwegian and Scottish salmon strains are known as extremely susceptible toinfection, whereas Baltic salmon races such as the Neva strain (Russian origin) and the Indals river (Swedish origin) salmon have been characterized as relatively resistant. However, the status of the many other Baltic strains has remained unknown. Thepresent study reports on the susceptibility of the Baltic salmon from the Swedish river Lule. It was shown that this strain is susceptible to infection but to a lesser extent than the Scottish salmon. Further studies showed that injection ofimmuno-suppressants (dexamethasone) greatly increased population growth of G. salaris on Scottish salmon but not on the Baltic salmon. Mucous cell density on fins differed between strains, and a general trend to decreased cell density on infectedfish 8 wk post-infection, compared to uninfected fish, was observed. The largest decrease in mucous cell density following infection was seen in the most resistant fish. After administration of immuno-suppressants, this decrease in mucous cell density wasinhibited in the Scottish salmon but not in the Baltic salmon. Thus, there seems to be a relationship between the fishes¹ ability to discard mucous cells and the ability to resist infections with Gyrodactylus salaris. Although the Lule salmonseems more susceptible to infection compared to previous reports on the Neva salmon, the results support the notion that Baltic salmon strains are generally more resistant than East Atlantic salmon.

【 授权许可】

Unknown