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

Exposure of Japanese medaka (Oryzias latipes) embryos and adult males to sublethal concentrations of two commonly used fungicides, Acrobat MZ and Tattoo C, had varying effects on development and adult male behavior. During embryolarval assays, medaka exposed to Acrobat exhibited decreased heart rates throughout embryonic development and were smaller at hatching than controls. Differences in hatching size were not apparent with Tattoo 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. Neither time to hatch nor early growth was affected by exposure to either fungicide. Adult males that had been exposed to high concentrations of Acrobat or Tattoo over a 28-day period were less likely to approach females during behavioral trials. The absence of other behavioral effects, particularly those related to reproductive performance, may have been due to females being sexually unreceptive during behavioral trials. No other behavioral modifications were apparent for adult males exposed to either fungicide. Information about developmental and behavioral responses to sublethal concentrations of pesticides is important for establishing environmental guidelines concerning their use.