title: [Toxicity of niclosamide with plastic film mulching to fish].
abstract: OBJECTIVE
  To observe the toxicity of niclosamide with plastic film mulching to fish.
  
  
  METHODS
  A ditch with Oncomelania snails was selected as the study site, and it was divided into a control group and a molluscicide group. After the river closure, the molluscicidal group was sprayed with niclosamide with a dosage of 2 g/m2, and then covered with plastic film; no molluscicide measure was implemented in the control group. The toxicity of the molluscicide to carp fish in resting and flowing water environment was observed.
  
  
  RESULTS
  In flowing water, the death rates of carp fry of the molluscicidal and control groups showed no statistical difference 7 d after the film mulching (P = 0. 680), and no carp fry died in the 2 groups after plastic film taking off for 4 d. The death rates of carp fry between the 3 sites (with a distance of 50, 100 and 150 m from the molluscicidal group, respectively) and the control group had no statistical difference 7 d after film mulching (P = 0.955), and no dead fry was discovered 4 d after taking off the film. In downstream, for the death rates of carp fry, there was no difference between the molluscicidal group and the control group (P = 0.376). The death rates of snails before and after the molluscicidal experiment showed a significant difference (P < 0.01).
  
  
  CONCLUSIONS
  The technology of niclosamide molluscicide with plastic film mulching can not only improve the molluscicidal effect, but also avoid the toxicity to fish, which is suitable for special environment such as a fish pond.
authors.affiliation: National Institute of Parasitic Diseases, Chinese Center for Disease Control and Prevention, Shanghai 200025, China.
authors.forename: Hong-Qing
authors.initials: HQ
authors.lastname: Zhu
authors.forename: Gui-Rong
authors.initials: GR
authors.lastname: Zhang
authors.forename: Bo
authors.initials: B
authors.lastname: Zhong
authors.forename: Shu-Gui
authors.initials: SG
authors.lastname: Tang
authors.forename: Chun-Li
authors.initials: CL
authors.lastname: Cao
authors.forename: Bin
authors.initials: B
authors.lastname: Jia
authors.forename: Yi
authors.initials: Y
authors.lastname: Zhang
authors.forename: Jian-Guo
authors.initials: JG
authors.lastname: Li
authors.forename: Tao
authors.initials: T
authors.lastname: Fu
authors.forename: Zi-Ping
authors.initials: ZP
authors.lastname: Bao
mesh_terms: D000818:Animals; D002347:Carps / Q000502:physiology*; D004777:Environment; D005618:Fresh Water / Q000469:parasitology*; D008975:Molluscacides / Q000008:administration & dosage / Q000633:toxicity*; D009026:Mortality; D009534:Niclosamide / Q000008:administration & dosage / Q000633:toxicity*; D010969:Plastics; D012908:Snails / Q000187:drug effects*; D013997:Time Factors; D014872:Water Movements
chemical_list: D008975:Molluscacides; D010969:Plastics; D009534:Niclosamide