It's over now. I saw some worms when I was trying to take the detail pictures... I moved the fish and the shrimp to a bucket. I took out all the water and put cold tap water in it. The temperature went down from around 77' to around 60'. I see all these guys shrinked, hopefully it will kill them all. The tank is in the middle of cycling and it only has java fern, hairgrass, a fish and a shrimp. I bought five fishes but 4 died so I wonder if it was because of the parasites and not ammonia spike.