DAO 42:149-152 (2000)  -  doi:10.3354/dao042149

Trichodina sp. (Ciliophora: Peritrichida) in eel Anguilla anguilla in recirculation systems in Denmark: host-parasite relations

Hans C. K. Madsen1, Kurt Buchmann2, Stig Mellergaard1,*

1Danish Institute for Fisheries Research, Department of Marine Ecology and Aquaculture, Fish Diseases Laboratory, 1870 Frederiksberg C, Denmark
2Royal Veterinary and Agricultural University, Section of Fish Diseases, 1870 Frederiksberg C, Denmark
*Corresponding author. E-mail:

ABSTRACT: Farmed eel cultured in recirculation systems in Denmark were found infected by Trichodina jadranica Raabe, 1958. Associations between parasite abundance and fish size was examined in 2 different production systems. In one system, stocked with relatively well-nourished eels (3 to 31 g), most of the parasites (66%) were found on the dorsal part on the skin and relatively few were found on the gills (approx. 8%). The infection level was significantly positively correlated both with fish weight and length. In the other system, stocked with relatively malnourished small eels (0.5 to 4 g), significantly more parasites (0.06 ± 0.02 [SD]) were present on fish with a low condition factor than on fish with a higher condition factor (0.13 ± 0.01 [SD]). In this eel stock the vast majority of the trichodines were found on the gills.


KEY WORDS: Eel · Trichodiniasis · Host-parasite relation · Recirculation system · Growth inhibition


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