Abstract
A new acute toxicity test method was developed using the larvae of Japanese Medaka (Oryzias latipes). The test was carried out in small glass petri dishes and was found to be feasible for simultaneously testing many chemicals. The most preferable larval stage and exposure period for the test were determined to be 48-72h posthatch with an exposure time of 48h. To obtain larvae for the test, adult pairs as many as 1/7 the number of larvae are required. The egg should be collected after 8 days of pairing, and the larvae hatched on the 9th or 10th day from commencement of embryo incubation at 25°C should be separated and cultured at a population density of less than 1.0g-weight·l-1. The calculated coefficients of variation of the test were 15% for 48-h LC50 and 22% for 48-h EC50. Using this method, the acute toxicity levels of eight widely used pesticides were evaluated. High toxicity levels were detected for diazinon and isoprothiolane, which were reported as low-toxicity pesticides in an acute toxicity test using Medaka adults.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
