報告書番号

U03047

タイトル（和文）

海水魚を用いた毒性試験法の開発（その2） -慢性毒性試験における適正試験条件の解明-

タイトル（英文）

Development of marine fish toxicity test methods (Part 2) - suitable conditions for chronic toxicity test-

概要 （図表や脚注は「報告書全文」に掲載しております）

慢性毒性値を求める際の試験条件を明らかにするために、体重0.2および0.5gのヒラメおよびマダイ稚魚を、水温20℃でホウ素および銅に56日間暴露した。(1)試験条件 いずれの魚種および物質についても慢性毒性を評価するには生死が適切な指標であると判断された。試験期間については淡水魚の試験ガイドラインで規定されている28日間が海水魚にも適用可能であると考えられた。対照区の生残率から、0.2g以下のマダイは慢性毒性試験に用いるには小さすぎると推察された。(2)慢性毒性値 ヒラメに対するホウ素の慢性毒性値は40mg-B/lと算定された。ヒラメおよびマダイに対する銅の慢性毒性値は、それぞれ0.3および0.04mg-Cu/lであり、ヒラメよりもマダイのほうが感受性は高かった。ヒラメに対するホウ素の急性慢性毒性比は3.3と算定された。

概要 （英文）

To clarify suitable chronic toxicity test conditions of Japanese flounder and red seabream, those initial body weight were 0.2 to 0.5 g, were exposed to boron and copper at 20 ℃ for 56 days.(1) Test conditionsSurvival rates and growth of Japanese flounder at 80 mg-B/l and 0.9 mg-Cu/l were significantly decreased, compared with control. Survival rates of red seabream significantly decreased at 60 mg-B/l and 0.12 mg-Cu/l, however, significant effect on growth was not observed. Chronic toxicity tests for 28 and 56 days showed almost same effects of boron and copper on survival and growth. From these results, it is suggested that a survival rate is a more sensitive index than growth to assess chronic effect. Test period of 28 days, recommended in the chronic toxicity test guidelines for freshwater fish, can be applicable for marine finfish. Survival rates of control groups of 0.5 g of red seabream and above 0.2 g of Japanese flounder in initial body weight were more than 90 % after 28 days, which is required as minimum survival rate of control in the chronic toxicity test guidelines for freshwater fish. Since that of red seabream of 0.2 g was 70 %, it is suggested that red seabream, smaller than 0.2 g, is too small to use for chronic toxicity test.(2) Chronic toxicity No observed effect concentrations (NOEC) of boron to Japanese flounder were estimated to be 40 mg-B/l. For copper, NOEC to Japanese flounder and red seabream were 0.3 and 0.04 mg-Cu/l, respectively. Therefore, seabream is more sensitive to toxic substances than Japanese flounder. Acute-chronic ratios of Japanese flounder were 3.3 for boron.

報告者

キーワード