평균체중 96 ± 3.6 g (평균전장 43 cm)의 극동산 뱀장어 (Anguilla japonica)에 대한 포르말린의 급성독성 실험 (수온 27～28℃, pH 7.4, 용존산소량 5.6 ppm)을 실시하였다. 특히 이 시험은 뱀장어에서 Pseudodactylogyrus 구제를 위해 포르말린을 사용할 때 치료농도에서 뱀장어가 안전한가를 평가하기 위해서 수행하였다. 포르말린 농도별 (0～500 ppm) 침지 후, 500 ppm에서는 10시간째, 400 ppm에서는 24시간째 전 실험어가 사망하였다. 24시간 경과한 후 300 ppm에서는 96.6% 그리고 200 ppm에서는 13.3%의 누적사망률을 각각 나타내었다. 그러나, 100 ppm에서는 24시간 동안 실험어가 모두 생존하였다. 뱀장어에 대한 포르말린의 24시간-LC50은 269 ppm으로 나타났다.
Acute toxicity of formalin (37% formaldehyde) was conducted to determine the median lethal concentration (LC50) on eel (avarage weight 96 ± 3.6 g, average total length 43 cm), Anguilla japonica at concentrations ranging from 0 to 500 ppm. In particular, this study was designed to estimate the safety concentrations of formalin in testing eels to eradicate Pseudodactylogyrus. All fish died after 10 hours and 24 hours at 500 ppm and 400 ppm, respectively. After 24 hours, cumulative mortality was 96.6% and 13.3% at 300 ppm and 200 ppm formalin, respectively. However, all experimental fish were alive after 24 hours at 100 ppm. The lethal concentration values were computed by using non-linear least square method. At the start of the test, water temperature, pH and dissolved oxygen level were 27～28℃, 7.4 and 5.55 ppm, respectively. The 24 hr-LC50 were 269 ppm.
