I saw one of these in my tank and now it looks like a hundred. I took a picture of it and the clearest one is in between where the white and blue meet on my algae scraper. Stuck that in the tank so my camera could get a clear pic. They look like little cells. Black dots inside a clear jelly? I saw one one day and thought oh, a snail lost its shell? Now there are a hundred and I think theyve cleaned up most of my algae on the tank walls which id rather leave for my cherry shrimp. And ive never actually seen them move either. Or sit there long enough to see movement? Any ideas?