This week in the micro-aquarium the variety  of organisms are much the same as last week, with a few exceptions. The relative numbers of the organisms continues to change, however. The diatoms, of several different species have exploded in number, recognizable by their small size and the yellow green refraction of light on their silica shells. 

The shelled amoebas have decreased in number, with the number of living approximately equal to the number of dead observed in the aquarium. The remains of centropyxis are especially numerous on the bottom layers of the water. 

Multiple species of algae continue to spread throughout the aquarium including the branched cladofora species identified last week, as well as an (unbranched) oedogonium species first spotted this week. In addition to the algae, the similarly filamentous cyanobacteria (also known as blue-green algae) oscillatoria and nodularia were observed this week. 

The elusive nematode (which I thought had died) made another appearance this week. It was observed tearing (feeding?) at some algal material with its mouth parts just above the soil layer at the bottom of the aquarium. 

Rounding out the observations this week were the previously documented protists limnias (multicellular), stentor (unicellular), and vorticella (unicellular) species, which continue to be amazing and strange. The highlight of this group this week was the vorticella, whose stalk was visible for the first time, attached to a filament of cladofora.