First record of the asian fish tapeworm schyzocotyle (Bothriocephalus) acheilognathi (yamaguti, 1934) in scandinavia

Abstract

This paper provides the first report of the invasive Asian fish tapeworm, Schyzocotyle (Bothriocephalus) acheilognathi (Yamaguti, 1934), from Norway and Scandinavia. The parasite was found during routine post mortem disease examination of an imported koi carp, Cyprinus carpio, from an outdoor pond in the North of Norway. The intestine contained live tapeworms and these tapeworms were identified as S. acheilognathi by DNA sequencing of partial 18S and 28S ribosomal DNA and comparison of the obtained sequences with sequences in GenBank. The infected fish specimen along with the other fish in the pond were exterminated. The risk of infection from the pond to other fish outside of the pond was thus negligible. However, the finding of S. acheilognathi in imported aquarium fish shows that such import poses a risk of introducing pathogens to new areas. Had this fish pond been situated in the south of Norway where the temperatures are higher and where susceptible hosts are readily available, an escape of fish or release of eggs from the pond could potentially have resulted in infection of local fish populations.