Tolerance of ciliated protozoan Paramecium bursaria (Protozoa, Ciliophora) to ammonia and nitrites     

许恒龙  宋微波  路璐  WARREN Alan 《中国海洋湖沼学报》2005,23(3)

1 INTRODUCTION Ammonia and nitrites are common pollutants in waters used for intensive aquiculture, and are harmful to cultured animals and their larvae when present in sufficiently high concentrations (Zhou, 1991). Ammonia in water is usually derived from animal excretion and catabolism of organic materi- als. It occurs in un-ionized and ionized forms. Un-ionized ammonia can pass through cell mem- brane and is harmful to the cells due to its fat-soluble feature (Chen, 2000; Chin, 2001).…  相似文献