Acute toxicities of potassium permanganate, formalin, and Lugol’s iodine solution to a marine ciliate, Pleuronema coronatum (ciliophora, scuticociliatida)

Acute toxicities of potassium permanganate, formalin, and Lugol's iodine solution to a commonly occurred marine ciliate Pleuronema coronatum (Ciliophora, Scuticociliatida) were measured. Linear regression analysis of the results highlighted the close relationships between doses of the medicines and mortalities of the organisms, thus providing a capability to predict toxicity effects from the dose. Toxic effects of the medicines on the ciliates were described in the present paper, and the median lethal concentrations (LC^sub 50^ values) were given. Results of measurements indicated that 2 h-LC^sub 50^ and 12 h-LC^sub 50^ values of formalin on P. coronatum were 59.00×10^sup -6^ and 43.57×10^sup -6^, while those of Lugol's solutions were 90.13 and 67.84×10^sup -6^ respectively. The tolerance of P. coronatum to formalin is apparently lower than that to Lugol's iodine solution and potassium permanganate is a suitable medicine to kill ciliates in short time.[PUBLICATION ABSTRACT]