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Start Over Creator Soleng, Arnulf

1. The susceptibility of three-spined stickleback (Gasterosteus aculeatus), nine-spined stickleback (Pungitius pungitius) and flounder (Platichthys flesus) to experimental infections with the monogenean Gyrodactylus salaris

Creator:
Soleng, Arnulf and Bakke, Tor A.
Format:
print
Type:
model:internalpart and TEXT
Subject:
host specificity, Gyrodactylus salaris, resistance, parasite dispersal, and transport host
Language:
English
Description:
Three-spined stickleback (Gasterosteus aculeatus L.), ninc-spined stickleback (Pungitius pungitius (L.)) and flounder 0Platichthys flesus (L.)) are widespread teleosts, which all have behaviours involving migration between freshwater and brackish/sea water environments. Their importance in dispersal of the freshwater monogenean Gyrodactylus salaris Malmberg, 1957, which causes heavy losses of Atlantic salmon (Salmo salar L.) parr in infected Norwegian rivers, was tested indirectly by their susceptibility and resistance to the parasite in laboratory experiments. Gyrodactylus salaris attached to the three fish species, but no parasite reproduction was observed. The infections were eliminated alter a maximum of 3 days on flounder, 6 days on nine-spined stickleback, and 8 days on three-spined stickleback. Thus these fishes are innately resistant to G. salaris, and are therefore of no importance concerning the population dynamics of G. salaris in freshwater systems. However, attachment of parasites indicates that these fish species may function as transport hosts, and theoretically play a part in the dispersal of G. salaris in nature.
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public

2. Transmission of the monogenean Gyrodactylus salaris

Creator:
Soleng, Arnulf, Jansen, Peder A., and Bakke, Tor A.
Format:
print
Type:
model:internalpart and TEXT
Subject:
Gyrodactylus salaris, Monogenea, temperature, transmission, and Salmo salar
Language:
English
Description:
The present study is focusing on the transmission of the monogenean ectoparasite Gyrodactylus salaris Malmberg, 1957, a major pathogen on natural populations of Norwegian Atlantic salmon, Salmo salar L. In laboratory experiments the transmission rate of G. salaris after direct host to host contact was positively correlated with water temperature (1.2, 4,7 and 12.2°C). The transmission of detached G. salaris in the planktonie drift was studied in field experiments where salmon parr were individually isolated for 24 hours in small wire mesh cages suspended in the water column. Ten out of 157 salmon parr (prevalence 6.4%, mean intensity 1.0) contracted G. salaris infections after this exposure. Furthermore, 200 uninfected marked salmon parr were released into the same area of the river. After 24 and 48 hours, respectively 18 and 19 marked parr were caught by electro-fishing. The prevalence of G. salaris was 44.4% (mean intensity 1.9) after 24 hours, rising to 57.9% (mean intensity 2.3) after 48 hours. Gyrodactylids have no specific transmission stage or swimming ability, but detached G. salaris drifting in the water column were found to infect salmon parr. However, the transmission rate was markedly higher to free-living fish, suggesting that transmission routes such as indirect transmission from the substrate or direct contact transmission from infected live and/or dead fish, are relatively more important than transmission by drifting detached parasites.
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public