Effects of Acrobat MZReg. and Tattoo CReg. on Japanese medaka (Oryzias latipes) development and adult male behavior

Exposure of Japanese medaka (O. latipes) embryos and adult males to sublethal concentrations of two commonly used fungicides, Acrobat MZ (a.i. are dimethomorph and mancozeb) and Tattoo C (a.i. are propanocarb and chlorothalonil) had varying effects on the development and adult male behaviour. During embryolarval assays, medaka exposed to Acrobat MZ exhibited decreased heart rates throughout embryonic development, and were smaller at hatching than controls. Differences in hatching size were not apparent with Tattoo C, although some decrease in heart rate was observed at higher concentrations. Tail lesions and abnormal spinal development was a problem common to embryos exposed to Acrobat MZ. Neither time to hatch nor early growth was affected by exposure to either fungicide. Adult males that had been exposed in high concentrations of Acrobat MZ (up to 4.0 mg/litre) or Tattoo C (up to 0.65 mg/litre) over a 28-day period were less likely to approach females during behavioural trials. The absence of other behavioural effects, particularly those related to reproductive performance, may have been due to females being sexually unreceptive during behavioural trials. No other behavioural modifications were apparent for adult males exposed to either fungicide. Information about developmental and behavioural responses to sublethal concentrations of pesticides is important for establishing environmental guidelines concerning their use..