Archamoebae

Pelomyxa (peal-o-mix-a), a large pelobiont which developed some reputation as possibly the most primitive eukaryote. This argument was based on the fact that it does not have mitochondria, conventional dictyosomes if any, flagella are aberrant, and nuclear division was also thought to be aberrant. The arguments for a primitive status now seem to be unsound. Cytoplasm with small particles of sand. eats algae and detritus. Moves with fountain-flow motion (cytoplasm moving forward up the centre of the cell and then spilling out near the front. Posterior end crumpled, to form a uroid. Phase contrast micrograph.

Pelomyxa (peal-o-mix-a), a large pelobiont which developed some reputation as possibly the most primitive eukaryote. This argument was based on the fact that it does not have mitochondria, conventional dictyosomes if any, flagella are aberrant, and nuclear division was also thought to be aberrant. The arguments for a primitive status now seem to be unsound. Cytoplasm with small particles of sand. eats algae and detritus. Moves with fountain-flow motion (cytoplasm moving forward up the centre of the cell and then spilling out near the front. With short inactive flagella over the surface of the cell. Posterior end crumpled, to form a uroid. Phase contrast micrograph.

Pelomyxa (peal-o-mix-a), a large pelobiont which developed some reputation as possibly the most primitive eukaryote. This argument was based on the fact that it does not have mitochondria, conventional dictyosomes if any, flagella are aberrant, and nuclear division was also thought to be aberrant. The arguments for a primitive status now seem to be unsound. Cytoplasm with small particles of sand. eats algae and detritus. Moves with fountain-flow motion (cytoplasm moving forward up the centre of the cell and then spilling out near the front. Posterior end crumpled, to form a uroid. Differential interference contrast.

Pelomyxa (peal-o-mix-a), a large pelobiont which developed some reputation as possibly the most primitive eukaryote. This argument was based on the fact that it does not have mitochondria, conventional dictyosomes if any, flagella are aberrant, and nuclear division was also thought to be aberrant. The arguments for a primitive status now seem to be unsound. Cytoplasm with small particles of sand. eats algae and detritus. Moves with fountain-flow motion (cytoplasm moving forward up the centre of the cell and then spilling out near the front. Posterior end crumpled, to form a uroid. Phase contrast micrograph.

Video showing how this amoebae collected at Cedar Swamps in Woods Hole moves around with a single anterior protruding pseudopode. This video made by Dan Lahr under a Zeiss Discovery V12, believe it or not, a dissecting scope.