Week 4

This week I observed many of the same organisms as previous weeks.  The largest and smallest organisms increased in number and the medium sized organisms decreased in number since the last observation. Diatoms seemed to get the biggest increase in number and size this week.

Below are diatoms of genus Pinnularia (Canter-Lund and Lund, 1995 p.118 Fig. 207).  The biggest one (Diatom A) was seen moving by moving water through the tube like body and propelling itself left or right.

Many were idle and floating by themselves, some of which (pictured below) were stacked for better structural protection from predators.

 This nematode of genus Tylenchorhynchus (below) was the only new animal spotted this week (Allen 1995).  It seemed to love to stay shielded in a layer of dirt, but was faster moving than the Duro annelid spotted last week (Covich and Thorp 2009, p.399 Fig12.5).

 This protist of genus Stentor was spotted near the bottom of the tank (MicrobeWiki, 2014).  It uses a filter feeding technique to bring food particles to it.  This two headed Stentor was attached to a decaying stem.

 This un-identified rotifer was spotted holding onto and spinning around the photosynthetic plant Amblestegium varium (McFarland, 2014).