Observation 2: Thursday, October 27

This week a food pellet was added to my MicroAquarium on October 21 ("Atison's Betta Food" made by Ocean Nutrition, Aqua Pet Americas, 3528 West 500 South, Salt Lake City, UT 84104. Ingredients: Fish meal, wheat flower, soy meal, krill meal, minerals, vitamins and preservatives. Analysis: Crude Protein 36%; Crude fat 4.5%; Crude Fiber 3.5%; Moisture 8% and Ash 15%).

I observed no major changes this week, except that the predominant organism I saw was the gastrotrich (or it was the predominant larger organism I saw).  Last week there were more tachysoma swimming about, so I can only guess that either the gastrotrich is a predator and has reduced their numbers, or the tachysoma have responded to the increased number of gastrotrich by hiding more in the substrate (which is the only place I saw any of them at all this week). 

There were about the same number of diatoms and photosynthetic organisms, but again, they were mostly concentrated near the bottom. 

Another small change was the number of rotifers I could see.  I saw maybe three last week, and this week there were at least twice that many, most of which were either anchored in the substrate or floating just above it.  I actually saw a philodina (pictured below) eat a small protist by sucking in in with its rotating head cilia, which was very cool! 

Overall, the numbers of other organisms and general location of them was the same:  small protists were concentrated higher up around plants A and B, and the larger ones were in and around the substrate at the bottom.  There were a couple filamentous-looking strands of algae growing out of the mud also.  I took several pictures, but only had time to identify a couple.  I will continue to post them as I can identify them.

Fig. 6.1.  2001.  Douglas Smith.

Fig. 7.11.  2001.  Douglas Smith