irenedesertis bestämningar

Found in my betta tank. A very bizarre case as my betta tank has effectively been isolated since its setup last February save for water changes (treated tap water).

There is no gravel in the tank, nor are there any live plants. All decor and equipment was new and sterile when I first added it.

I am curious as to how these specimens arrived in my home; they may have come through a nearby window or remained as eggs somewhere in my house (I cultured hydra about three years ago). Either way, very interesting.

One specimen was taken for photography under the microscope. 40x magnification was used. The specimen was then returned to the aquarium (last picture).

Magnification of photos: 40×, 100×, 100×, 100×, 600×, 600×. First three images were taken using a handheld microscope.
Habitat: slow-moving fresh water from the Charles River Esplanade. Associated plants: Nymphaea odorata, Utricularia sp.
Photos taken with a Celestron PentaView Digital Microscope. According to their website, the FOV (i.e. the diagonal width) at 40× is 1.5 mm.
Last two photos show stenotele nematocysts, found in the same sample.

Video link: https://youtube.com/shorts/Jb2eq_JayVs?si=3E_z6Yag5a_rm3o7

Growing on sponge filter in minnow and snail tank
Still when first observed. I moved a plant and stirred up some mulm. Here, they are consuming the mulm from the water column.

These appear white, unlike the vibrant green of some hydra. I'm not sure if these actually are white/clear or if the lighting at the back of the tank alters their appearance on camera. The transparent body of hydra might show what they are eating.
Edit: turns out some species contain symbiotic strains of algae, which makes them green, although they don't consume it.