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).

Week 3

Over the past week the number of both large organisms and small organisms increased.  New species of each were spotted.  There were many stationary diatoms and small dead organisms.

This unidentified protist showed up near the leaves of my plant to eat some algae growing there.  The front end was covered in cilia.

Six members of genus Actinosphaerium were spotted.  The spike protruding from the mucilaginous layer around the cell are known as spicules.  Five of them were connected by specialized tubing (Patterson 2013, p.169 Fig.395)

One shelled amoeba of genus Centropyxis was spotted near the middle of the tank not moving (Patterson 2013,p.95 Fig.184).

One member of Gastrotricha genus Chaetonotus was spotted swimming in the lower middle of the tank (Pennak 1989, p.165 Fig.7).

I spotted the tail end and oxygen harvesting gills of an immature annelid of genus Dero hiding among the muck at the bottom of the tank (Covich and Thorp 2009, p.399 Fig12.5).