title: Acute toxicity of organophosphate insecticide, dichlorvos in relation to selected water hardness for the freshwater zooplankters.
abstract: Toxicity of organophosphate insecticide, i.e. dichlorvos has been investigated in relation to selected water hardness for the freshwater zooplankters such as Moina, Daphnia, cyclops and nauplii. Results revealed that dichlorvos was highly toxic to the tested zooplankters, as the LC50 values are noticed in ppb. Trend of sensitivity for different zooplankters to dichlorvos was recorded as Moina < Daphnia < nauplii < cyclops. The LC50 were found to change significantly with the change in water hardness. The zooplankters were more susceptible to dichlorvos at water hardness of 275 mgl(-1) as compared to water hardness of 540 mgl(-1) as revealed from low LC50 values. The range of safe dischargeable concentrations (1.063-1.137ppb) were too low as compared to harmless or safe concentrations (43.895-89.194 ppb) for the zooplankters at both the hardness.
authors.affiliation: College of Fisheries, Maharana Pratap University ofAgriculture and Technology, Udaipur 313 001, India. drashokgupta9712@rediffmail.com
authors.forename: Ashok Kumar
authors.initials: AK
authors.lastname: Gupta
authors.forename: Girraj Prasad
authors.initials: GP
authors.lastname: Verma
authors.forename: Khyali Lal
authors.initials: KL
authors.lastname: Jain
mesh_terms: D000818:Animals; D004006:Dichlorvos / Q000633:toxicity*; D005618:Fresh Water / Q000737:chemistry*; D007306:Insecticides / Q000633:toxicity*; D007928:Lethal Dose 50; D013997:Time Factors; D023382:Toxicity Tests, Acute; D014874:Water Pollutants, Chemical / Q000633:toxicity*; D015048:Zooplankton / Q000187:drug effects*
chemical_list: D007306:Insecticides; D014874:Water Pollutants, Chemical; D004006:Dichlorvos