Herbicides are being used widely in agriculture and aquaculture for controlling noxious weeds. Paraquat and 2, 4-Dichlorophenoxyacetic acid(2,4-D) have been the most widely used herbicide during the past three decades. Toxicological properties of Paraquat are attributed to its abilityto produce reactive oxygen species such as superoxide anion that may directly or indirectly cause cell death. 2,4-Dichlorophenoxyacetic acid(2,4-D) is a broad-leaf, systemic, phenoxy herbicide used as the active ingredient in several commercially available aquatic herbicide products.Bioassay technique has been the cornerstone of programs on environmental health and chemical safety. The application of environmentaltoxicology studies on non-mammalian vertebrates is rapidly expanding. So the present study investigated the acute toxicity of Paraquat and2,4- Dichlorophenoxy acetic acid (2,4-D) as aquatic ecosystems pollutants on Artemia franciscana. Artemia is one of the most suitable testorganisms available for ecotoxicity testing and research and most commonly used live food in aquaculture. Acute toxicity (48 h LC50) of twoherbicides (Paraquat, 2, 4-dichlorophenoxy acetic acid) was determined. A. franciscana exposed to Serial concentrations of both mentionedherbicides. Mortalities at 12, 24, 36 and 48 hours after exposure were recorded and LC50 were calculated using Probit software. The resultsobtained indicate that the acute toxicity of these herbicides is significantly different in adult A. franciscana. The lethal concentration of Paraquatand 2,4-D were calculated 2.701, 14.475 mg/L in A. fransiscana respectively. So The LC50 of two examined herbicides was significantly differentand the mortality rate was increased by increasing exposure time. Finally, these data support the hypothesis the possible risks associatedwith the presence of herbicides particularly Paraquat residues in the aquatic animals and their environment.

Herbicides are being used widely in agriculture and aquaculture for controlling noxious weeds. Paraquat and 2, 4-Dichlorophenoxyacetic acid(2,4-D) have been the most widely used herbicide during the past three decades. Toxicological properties of Paraquat are attributed to its abilityto produce reactive oxygen species such as superoxide anion that may directly or indirectly cause cell death. 2,4-Dichlorophenoxyacetic acid(2,4-D) is a broad-leaf, systemic, phenoxy herbicide used as the active ingredient in several commercially available aquatic herbicide products.Bioassay technique has been the cornerstone of programs on environmental health and chemical safety. The application of environmentaltoxicology studies on non-mammalian vertebrates is rapidly expanding. So the present study investigated the acute toxicity of Paraquat and2,4- Dichlorophenoxy acetic acid (2,4-D) as aquatic ecosystems pollutants on Artemia franciscana. Artemia is one of the most suitable testorganisms available for ecotoxicity testing and research and most commonly used live food in aquaculture. Acute toxicity (48 h LC50) of twoherbicides (Paraquat, 2, 4-dichlorophenoxy acetic acid) was determined. A. franciscana exposed to Serial concentrations of both mentionedherbicides. Mortalities at 12, 24, 36 and 48 hours after exposure were recorded and LC50 were calculated using Probit software. The resultsobtained indicate that the acute toxicity of these herbicides is significantly different in adult A. franciscana. The lethal concentration of Paraquatand 2,4-D were calculated 2.701, 14.475 mg/L in A. fransiscana respectively. So The LC50 of two examined herbicides was significantly differentand the mortality rate was increased by increasing exposure time. Finally, these data support the hypothesis the possible risks associatedwith the presence of herbicides particularly Paraquat residues in the aquatic animals and their environment.