Karvonen Anssi, Paukku Satu, Seppälä Otto, Valtonen E Tellervo
Department of Biological and Environmental Science, University of Jyväskylä, P.O. Box 35, 40014, Jyväskylä, Finland.
Parasitol Res. 2005 Jan;95(1):55-9. doi: 10.1007/s00436-004-1246-x. Epub 2004 Nov 25.
A central issue in fish production is the influence of parasitic infections on fish health in fish farms and on survival prospects after fish-stocking into the wild. Is it preferable to produce fish in infection-free conditions or to allow some infection to elicit resistance in fish? We explored the infection of totally naive and previously infected rainbow trout (Oncorhynchus mykiss) by the trematode parasite Diplostomum spathaceum in laboratory conditions. We found that up to 86.1% of the presented cercariae became established in the lenses of naïve fish, which indicated that these fish were highly susceptible to infection and that innate resistance served little or no protection against the parasite. However, acquired resistance after initial infection decreased parasite establishment by 85.0-89.1%. Parasite establishment was also affected by fish host density as fewer parasites were found in fish in higher densities. The implications of these results for the fish-farming industry and fish-stocking protocols are discussed.
鱼类生产中的一个核心问题是寄生虫感染对养鱼场中鱼类健康以及放流到野外后生存前景的影响。是在无感染条件下养殖鱼类更好，还是让一些感染引发鱼类的抵抗力更好呢？我们在实验室条件下探究了完全未感染过和先前已感染过的虹鳟（Oncorhynchus mykiss）被吸虫寄生虫双穴吸虫（Diplostomum spathaceum）感染的情况。我们发现，多达86.1%的尾蚴在未感染过的鱼的晶状体中定殖，这表明这些鱼对感染高度易感，且先天抵抗力对该寄生虫几乎没有或根本没有保护作用。然而，初次感染后的获得性抵抗力使寄生虫定殖减少了85.0 - 89.1%。寄生虫定殖还受鱼类宿主密度的影响，因为在密度较高的鱼中发现的寄生虫较少。本文讨论了这些结果对养鱼业和放流规程的影响。
