養殖ウナギのえらに寄生する?EＰｓｅｕｄｏｄａｃｔｙｌｏｇｙｒｕｓ ｍｉｃｒｏｒｃｈｉｓ?F（吸虫類単生目） ＩＩＩ トリクロルホンによる実験的駆虫

Abstract

In the first experiment, the effects of trichlorfon, formalin and sodium chloride baths on the control of Pseudodactylogylus microrchis on eels (Anguilla anguilla) were studied comparatively. As a result, the 0.5 ppm•24 hour-bath of trichlorfon proved to be potentially practical in both respects of effectiveness and harmlessness. In the second experiment, the effective way of treatment with 0.5 ppm•24 hour trichlorfon bath was examined. In consequence, a double 0.5 ppm•24 hour-bath of trichlorfon with an adequate interval was confirmed to be completely effective for the control of the worm. The second bath was found to be indispensable, because the eels became reinfected with the young forms hatched from eggs which were laid during the first bath. The interval between the first bath and the second bath depends on the time required for hatching of the eggs. And, actually, 3 days interval proved adequate at the experimental water temperature of 25.5-28°C.