title: Laboratory toxicity test and post-exposure feeding inhibition using the giant freshwater prawn Macrobrachium rosenbergii.
abstract: A bioassay was developed using post-larvae of freshwater prawn Macrobrachium rosenbergii (length 9-10 mm) in order to determine the toxicity of profenofos, dimethoate, chlorpyrifos, carbendazim and zinc. This was the first study in the tropics with M. rosenbergii, particularly at the post-larvae stage (9-10 mm) on lethal (LC(50)) and sublethal (EC(50)) effects of toxic substances using post-exposure feeding rate as end point. Median lethal concentrations (LC(50) at 24 and 48 h) were respectively estimated as 11.6 and 9.8 microg L(-1) for profenofos, 142.1 and 102.7 microg L(-1) for dimethoate, 0.7 and 0.3 microg L(-1) for chlorpyrifos, and 439.7 and 329 microg L(-1) for zinc. Effects of carbendazim could not be estimated because carbendazim exposure needs more than 24h exposure period to produce observable effects at the concentrations used. The EC(50) using post-exposure feeding rates determined for profenofos, dimethoate, chlorpyrifos and zinc were 6.023, 269.3, 0.293 and 109.01 microg L(-1), respectively, at 24 h of exposure. Only chlorpyrifos and zinc had LC(50) concentrations greater than the post-exposure feeding EC(50) concentrations. This study demonstrated that the M. rosenbergii could also be used as a test animal to detect the effects of different chemical contaminants in aquatic environments.
authors.affiliation: Department of Fishery Biology, Faculty of Fisheries, Kasetsart University, Bangkhen, Chatuchak, Bangkok 10900, Thailand. ffiskks@ku.ac.th
authors.forename: Kriengkrai
authors.initials: K
authors.lastname: Satapornvanit
authors.forename: D J
authors.initials: DJ
authors.lastname: Baird
authors.forename: D C
authors.initials: DC
authors.lastname: Little
mesh_terms: D000818:Animals; D001562:Benzimidazoles / Q000633:toxicity; D001681:Biological Assay / Q000379:methods; D002219:Carbamates / Q000633:toxicity; D004390:Chlorpyrifos / Q000633:toxicity; D004117:Dimethoate / Q000633:toxicity; D005247:Feeding Behavior / Q000187:drug effects*; D007928:Lethal Dose 50; D063086:Organothiophosphates / Q000633:toxicity; D033541:Palaemonidae / Q000187:drug effects*; D018675:Toxicity Tests / Q000379:methods; D014874:Water Pollutants, Chemical / Q000633:toxicity*; D015032:Zinc / Q000633:toxicity
chemical_list: D001562:Benzimidazoles; D002219:Carbamates; D063086:Organothiophosphates; D014874:Water Pollutants, Chemical; C024273:profenofos; C006698:carbendazim; D015032:Zinc; D004390:Chlorpyrifos; D004117:Dimethoate