title: Mass Death of Predatory Carp, Chanodichthys erythropterus, Induced by Plerocercoid Larvae of Ligula intestinalis (Cestoda: Diphyllobothriidae).
abstract: We describe here the mass death of predatory carp, Chanodichthys erythropterus, in Korea induced by plerocercoid larvae of Ligula intestinalis as a result of host manipulation. The carcasses of fish with ligulid larvae were first found in the river-edge areas of Chilgok-bo in Nakdong-gang (River), Korea at early February 2016. This ecological phenomena also occurred in the adjacent areas of 3 dams of Nakdong-gang, i.e., Gangjeong-bo, Dalseong-bo, and Hapcheon-Changnyeong-bo. Total 1,173 fish carcasses were collected from the 4 regions. To examine the cause of death, we captured 10 wondering carp in the river-edge areas of Hapcheon-Changnyeong-bo with a landing net. They were 24.0-28.5 cm in length and 147-257 g in weight, and had 2-11 plerocercoid larvae in the abdominal cavity. Their digestive organs were slender and empty, and reproductive organs were not observed at all. The plerocercoid larvae occupied almost all spaces of the abdominal cavity under the air bladders. The proportion of larvae per fish was 14.6-32.1% of body weight. The larvae were ivory-white, 21.5-63.0 cm long, and 6.0-13.8 g in weight. We suggest that the preference for the river-edge in infected fish during winter is a modified behavioral response by host manipulation of the tapeworm larvae. The life cycle of this tapeworm seems to be successfully continued as the infected fish can be easily eaten by avian definitive hosts.
authors.affiliation: Department of Parasitology and Tropical Medicine, and Institute of Health Sciences, Gyeongsang National University School of Medicine, Jinju 52727, Korea.
authors.forename: Woon-Mok
authors.initials: WM
authors.lastname: Sohn
authors.affiliation: Department of Parasitology and Tropical Medicine, and Institute of Health Sciences, Gyeongsang National University School of Medicine, Jinju 52727, Korea.
authors.forename: Byoung-Kuk
authors.initials: BK
authors.lastname: Na
authors.affiliation: Korea Federation for Environmental Movements in Daegu, Daegu 41259, Korea.
authors.forename: Soo Gun
authors.initials: SG
authors.lastname: Jung
authors.affiliation: Nakdong River Integrated Operations Center, Korea Water Resources Corporation, Busan 49300, Korea.
authors.forename: Koo Hwan
authors.initials: KH
authors.lastname: Kim
mesh_terms: D000818:Animals; D003530:Cyprinidae / Q000469:parasitology*; D005393:Fish Diseases / Q000453:epidemiology* / Q000401:mortality* / Q000473:pathology; D007723:Korea; D059208:Parasite Load; D013031:Sparganosis / Q000453:epidemiology / Q000401:mortality / Q000473:pathology / Q000662:veterinary*; D013032:Sparganum / Q000302:isolation & purification*
keywords: Chanodichthys erythropterus; Ligula intestinalis; host manipulation; plerocercoid; predatory carp