Aggregative behavior of the swordtip squid (Loligo edulis) under fishing lights in the coastal waters of northern Taiwan.

Abstract

爲探討抗生物附著劑(antifouling agent)三丁基錫(tributyltin,TBT)對沿岸性花身雞魚(Terapon jarbua Forsskal)之毒性影響，本實驗利用仔魚(juvenile)及幼魚(young)分別進行24小時半致死濃度測定，結果依死亡或然率(probability mortality)模式求得TBT對仔魚及幼魚之24小時半致死劑量分別爲19.7及135.0 μg／L。並利用石蠟切片及掃描式電子顯微鏡研究其幼魚曝露於0，10，50，100 μg／L TBT 7天後鰓部呈現之病變。由鰓部形態學觀察則發現在TBT處理下鰓絲有融合(lamella fusion)現象，濃度達50，100 μg／L時於鰓上皮細胞有明顯腫脹及上表皮分離。在掃描式電子顯微鏡觀察下則發現黏液細胞增殖及上表皮細胞壞死現象。To investigate the toxic effects of tributyltin(TBT)on coastal marine teleosts,thejuvenile and young thornfish(Terapon jarbua Forsskal)were subjected to 24hr LC50 testand a morphological examination of the epithelial tissue of gill.After exposure to variousTBT concentrations for 24 hours,the mortality rates measured for modeling their LC50value,were found to be 19.7 and 135.0 μg/L for juvenile and young thornfish,respectively.Young fish,which were exposed to 50 and 100 μg/L TBT for seven days,revealed anoticeable edema,hyperplasia and necrosis of gill epithelium through a pathomorphologicalinvestigation(both light and scanning electron microscopy investigation).The presentresults hence indicate that the epithelial tissue damage of the gills may cause hypoxia andeven death.