Following a trip to the lake in which i usually go fishing, i came back with goodies to add to the jar. Scraped some muck off submerged stones, as well as from a dead branch. Also collected a sample of green algae developing about half a meter underwater close to the shore.
As the jar is already full, I only took a very small water sample, maybe 10ml or so, with very fine gravel (.5cm3). The lake is an old stone quarry, abandoned 20 years ago and transformed in a bird reserve / fishing pond. It’s close to a rather large river that runs nearby and I imagine there are exchanges between the two bodies of water, maybe via underground waters. I am led to believe this because they release trout in it, which needs high levels of oxygen, usually insufficient in stale pond water full of algae.
This green moss-looking plant was emerging from the brown dead grass on the shore, so I took a handful with the aim of increasing the oxygen production in my jar swamp. Not sure this will survive given the fact that it’s fully submerged and has little to no soil. In the worst case it will decay and provide nutrients..
Riding back there I found a fresh water source on the side of a hill – collected some soil and some of those undulating water plants that move suavely with the flow. After closer inspection I saw a plastic tube that was channeling the stream – I just hope it’s not pesticide-infested irrigation water as there are some vineyards on the surrounding hill sides.
Given the little space I have available, I decided to remove the tree moss that was rotting in the jar. The mass of long, thin algae was particularly difficult to separate from it, but I managed to conserve most of it. I also left some moss, as when I first collected it I had found a water bear, which are undoubtedly among the coolest creatures alive.
While transferring all of the above to the jar, I took samples for closer inspection – algae, moss, soil, water and some of that decomposing muck I had scraped off the bottom. Living things were clearly visible to the naked eye and I made sure to suck up some of them in my pipette. An earthworm (would have been perfect for fishing – next time I know where to look for them) was among the moss so i mercifully put him in one of my flower pots outside.
One remarkable thing that I found was a 5mm gelatinous blob that has the consistency of snot (almost wiped it off first I saw it).
This turned out to be an egg-sack containing a dozen or so eggs, which are very much alive. 400x magnification shows the embryo being composed of several cells, tightly stuck together to form a slow-moving sphere.
I’ve carefully placed it back in the jar and marked the spot so that I can remove it for future observations. Bets are open as to what will hatch.
In the small sample of water I collected from the pond there were two very agitated creatures, a few millimeters long, that i first mistook for nematode worms. I had inadvertently trapped one under the slide glass, so it did not move at all and could thus inspect the digestive system.
Inspecting the deposits on the walls of the jar I found yet another sack of eggs, significantly smaller and with only a few eggs inside. Looks flat.