Biology of the Precambrian Genus Kakabekia: New Observations on Living Kakabekia barghoorniana

Abstract

Kakabekia barghoorniana Siegel, living species of a fossil genus Kakabekia , has now been cultured from Alaskan soil samples obtained from the Mendenhall Glacier near Juneau and from the Point Barrow region above the Arctic Circle. Morphological comparisons, especially of mantle variations, show that fossil and living populations overlap in many details. Cytochemical tests demonstrate that living Kakabekia has no storage forms of lipid or polysaccharide and no phenoloxidase. Some individuals (19-33%) contain heme enzymes but most do not; hence they cannot utilize O 2 even in air.