Population Growth in Stationary and Suspension Culture of Paramoeba pemaquidensis Page (Amoebida, Paramoebidae)1

Paramoeba pemaquidensis Page requires attachment to a substrate in order for population growth to occur. Populations of amoebae suspended in bacterized culture media on a roller tube apparatus did not increase in size whereas amoebae maintained in stationary control tubes multiplied in number. Amoebae maintained in suspension for as long as three weeks attached and multiplied in culture when allowed to settle. This suggests that Paramoeba found suspended in the surface microlayer of the ocean may be in a “dormant” state. Implications for the survival and geographic distribution of the genus are discussed.