報告書番号

U03048

タイトル（和文）

海水魚を用いた毒性試験法の開発（その3） -―ライフサイクル試験装置および試験対象種の検討―-

タイトル（英文）

Development of marine fish toxicity method (Part 3) - Experimental apparatus and marine finfish species applicable to long-term life cycle toxicity tests

概要 （図表や脚注は「報告書全文」に掲載しております）

海水魚のライフサイクル試験法を開発する目的で、銅、ホウ素について循環濾過式方式の適用可能性を検討するとともに、試験対象魚種の探索を行なった。 1. 200mg-B/lまでのホウ素、0.2mg-Cu/lまでの銅はアンモニア酸化を阻害せず、溶存態濃度の維持も可能と考えられた。 2. カクレクマノミでは約15日間隔で400尾程度の孵化仔魚が得られたが、2年間では仔魚は産卵にまでは至らなかった。ブラックモーリーは海水中で、約40日ごとに40尾を産仔し、稚魚は産仔にまで至った。 3. 銅、ホウ素を添加した海水中でブラックモーリー親魚を飼育した結果、稚魚や親魚の生残率に影響が認められたが、産仔数や産仔間隔への影響は明確ではなかった。 以上の結果から、循環濾過式水槽でのホウ素や低濃度の銅のライフサイクル試験が可能であり、対象魚としてブラックモーリーが利用可能と考えられた。

概要 （英文）

Effects of copper and boron on nitrification in seawater closed recirculating system, and their dissolved concentration in the culture water were examined. Spawning of a few fish species in small aquarium was also observed to seek for suitable species to long-term life cycle toxicity experiments.Boron of lower than 200 mg-B/l and copper of lower than 0.5 mg-Cu/l in concentration have little effects on the nitrification rate of seawater closed recirculating system for 12 weeks of experimental period. Concentration of boron was almost constant regardless of the level, however, that of copper tended to decrease with time. We could keep copper concentration by ad libitum supplying, if the level was lower than 0.2 mg-Cu/l.False clown anemonefish larvae could be obtained biweekly throughout the year under the conditions of 26ｰC in water temperature and 15 hours of light and 9 hours dark. However, none of hatched fish matured. Black molly larvae were also successfully obtained in 40 days intervals under similar rearing condition and some of the hatched larvae grew adults and spawned.A 13 weeks exposure test of boron and copper were conducted with black molly. Effects of adults and hatched larvae were examined in terms of survival, spawning intervals, numbers of larva and growth. Effects of copper and boron were observed in survival rates of larvae and adults, but not in growth, spawning intervals and numbers of larva. These results showed that long-term life cycle toxicity experiments of boron and low level copper can be carried out in seawater closed recirculating system with black molly.

報告者

キーワード