MEPS 160:101-108 (1997)  -  doi:10.3354/meps160101

Growth and consumption rates of bacterivorous Antarctic naked marine amoebae

Daniela F. Mayes1, Andrew Rogerson2,*, Harvey Marchant3, Johanna Laybourn-Parry4

1University Marine Biological Station Millport, KA28 0EG, Scotland, United Kingdom
2Department of Chemistry and Chemical Engineering, South Dakota School of Mines and Technology, Rapid City, South Dakota 57701, USA
3Australian Antarctic Division, Channel Highway, Kingston, Tasmania 7050, Australia
4Department of Physiology and Environmental Science, University of Nottingham, Sutton Bonington Campus, Loughborough LE12 5RD, United Kingdom
*Addressee for correspondence. E-mail:

This is the first study to consider the growth and feeding rates of naked marine amoebae at temperatures below 5°C. Specific growth rates were calculated for 5 Antarctic isolates, Platyamoeba australis, Mayorella sp., Metachaos sp., Vannella sp., and an unidentified vahlkampfiid amoeba. Growth rates ranged between 0.08 x 10-2 and 2.9 x 10-2 h-1 corresponding to generation times of 866.2 and 23.9 h, respectively. All isolates grew at temperatures down to -2°C and showed optimal growth at 2°C although one species grew best at 0°C. A direct counting method was used to estimate bacterial feeding rates of P. australis and the vahlkampfiid amoeba. Rates varied as a function of prey density but were largely independent of temperature. Overall, amoebae consumed between 0.5 and 66.4 bacteria amoeba-1 h-1, equivalent to 0.3 and 38.0 pg C cell-1 h-1. Growth efficiencies estimated for these 2 amoebae were low, typically <2%, suggesting that amoebae incur high energetic costs for life at low temperatures.


Gymnamoebae · Protozoa · Generation times · Feeding · Growth efficiencies


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