#ostrocod

“Ophyroglena is a genus of histophagous ciliates, meaning that they feed on tissue. The one we're watching here has been drawn to this crustacean like a shark smelling a drop of blood in water, except it's a microbe drawn to a crack in its shell. And once it gets inside, the ophryglena gorges on the tissue inside.”

Journey to the Microcosmos- Ophyroglena: The Tricky Transforming Ciliate

Ostrocods in a whisky bottle. Commonly named seed shrimps, which is a bit odd because they are neither seeds nor shrimps. This has actually been one of the most interesting 'jar' despite it's simplicity. The ostrodods seem to feed on both the algae and the leaf littler but also spend a fair amount of time free swimming about in the water column. And occasionally they will congregate at the bottom for reasons I am yet to understand.

When they are disturbed they will swim downwards to find shelter, but recently they've been habituated to it and react with less enthusiasm. My heating in the flat hasn't been working and these guys act as a thermometer because they are a lot less active in colder temperatures. Another nice things about this jar is it seems stable for the moment, the population numbers haven't exploded or died down.