title: Fish tapeworm Khawia sinensis: an indicator of environmental microcystins?
abstract: OBJECTIVE
  Parasites have recently been recognized as accumulation indicators that take up and bio-concentrate substances from environmental pollution. Interestingly, helminths of fish are known to accumulate metals from the ambient environment and to contain several orders of magnitude higher concentrations than hosts. While the majority of reports mention inorganic toxin accumulation in parasites, studies concerning effects of organic pollution are infrequent and little is known about the potential of parasites to bio-accumulate microcystins.
  
  
  METHODS
  The parasite-host system of tapeworm Khawia sinensis and common carp (Cyprinus carpio) was used to address this issue. Both the tapeworms and livers were dissected from experimental carps orally exposed to cyanobacterial biomass for 20 days. The total dose of microcystins amounted to 27 mg/kg of feed, i.e., 0.4 mg/kg of fish mass a day. Microcystin concentrations in tapeworms and carp liver tissues were measured using the LC-MS/MS method.
  
  
  RESULTS
  Considering the three measured microcystin variants LR, YR and RR, only MC-RR was detected and its concentrations in tapeworms and carp liver tissue amounted to 5.78±3.78 ng/g and 2.11±0.74 ng/g fresh weight (p<0.05), respectively.
  
  
  CONCLUSIONS
  Here we show accumulation of microcystin MC-RR in the tapeworm Khawia sinensis, a parasite of common carp (Cyprinus carpio). As this is the first report addressing this issue, further studies will be necessary to examine this specific parasite-host system.
authors.affiliation: Department of Ecology and Diseases of Game, Fish and Bees, Faculty of Veterinary Hygiene and Ecology, University of Veterinary and Pharmaceutical Sciences Brno, Czech Republic. pikulaj@vfu.cz.
authors.forename: Miroslava
authors.initials: M
authors.lastname: Palikova
authors.affiliation: Research Centre for Toxic Compounds in the Environment (RECETOX), Masaryk University - Faculty of Science Brno, Czech Republic.
authors.forename: Ondrej
authors.initials: O
authors.lastname: Adamovsky
authors.affiliation: Research Centre for Toxic Compounds in the Environment (RECETOX), Masaryk University - Faculty of Science Brno, Czech Republic.
authors.forename: Ludek
authors.initials: L
authors.lastname: Blaha
authors.affiliation: Department of Fishery and Hydrobiology, Faculty of Agronomy, Mendel University, Brno, Czech Republic.
authors.forename: Jan
authors.initials: J
authors.lastname: Mares
authors.affiliation: Department of Fishery and Hydrobiology, Faculty of Agronomy, Mendel University, Brno, Czech Republic.
authors.forename: Radovan
authors.initials: R
authors.lastname: Kopp
authors.affiliation: Department of Ecology and Diseases of Game, Fish and Bees, Faculty of Veterinary Hygiene and Ecology, University of Veterinary and Pharmaceutical Sciences Brno, Czech Republic.
authors.forename: Stanislav
authors.initials: S
authors.lastname: Navratil
authors.affiliation: Department of Ecology and Diseases of Game, Fish and Bees, Faculty of Veterinary Hygiene and Ecology, University of Veterinary and Pharmaceutical Sciences Brno, Czech Republic.
authors.forename: Zdenka
authors.initials: Z
authors.lastname: Cutakova
authors.affiliation: Department of Ecology and Diseases of Game, Fish and Bees, Faculty of Veterinary Hygiene and Ecology, University of Veterinary and Pharmaceutical Sciences Brno, Czech Republic.
authors.forename: Zdenka
authors.initials: Z
authors.lastname: Soukupova
authors.affiliation: Department of Ecology and Diseases of Game, Fish and Bees, Faculty of Veterinary Hygiene and Ecology, University of Veterinary and Pharmaceutical Sciences Brno, Czech Republic. pikulaj@vfu.cz.
authors.forename: Jiri
authors.initials: J
authors.lastname: Pikula
mesh_terms: D000818:Animals; D002347:Carps / Q000469:parasitology*; D002589:Cestoda / Q000737:chemistry / Q000302:isolation & purification / Q000378:metabolism*; D004787:Environmental Pollution / Q000032:analysis*; D006790:Host-Parasite Interactions; D008387:Marine Toxins; D052998:Microcystins / Q000032:analysis / Q000378:metabolism*
chemical_list: D008387:Marine Toxins; D052998:Microcystins; C063855:microcystin RR; C057862:cyanoginosin LR