Alpine bullhead (Cottus poecilopus Heckel): a potential refuge for Gyrodactylus salaris Malmberg, 1957 (Monogenea)

• Published in: Folia Parasitologica
• Main Authors: Bakke, Tor A., Paterson, Rachel A., Cable, Jo
• Format: Article in Journal/Newspaper
• Language: unknown
• Subjects: Gyrodactylidae; Siberian bullhead; Atlantic salmon; reservoir host; experimental infection; Norway; Salmo salar
• Online Access: https://kramerius.lib.cas.cz/view/uuid:48c4160b-5a0a-4d7c-82b4-1089ab965dda; https://doi.org/10.14411/fp.2019.018

The notifiable freshwater pathogen Gyrodactylus salaris Malmberg, 1957 tends to be a generalist in contrast to other monogeneans. Whilst it causes most damage to its primary host, the Atlantic salmon (Salmo salar Linnaeus), transport and reservoir hosts likely play a key role in maintaining the parasite in the environment. Here, we tested the ability of G. salaris (strain River Lierelva, southern Norway) to infect and reproduce on a population of wild caught alpine bullhead (Cottus poecilopus Heckel). Exposure of alpine bullhead yearlings (0+) to G. salaris for 24 h at low (6.5 °C) or high temperature (11.5 °C) resulted in the establishment of 1 to 104 parasites per fish. Eight to nine days post-infection at high temperature, the infection of G. salaris was eliminated, indicative of innate host immunity. In contrast, at low temperature G. salaris infections persisted for 47-48 days. The relative lengthy infection of alpine bullhead with G. salaris compared to other non-salmonids tested may be due to low temperature and high initial infection load in combination with an epibiont infection. The present results suggest that this non-salmonid may function as a temperature-dependent transport or reservoir host for G. salaris.