I bought 10 Amano shrimp and could find only 2. A week or 2 later I found all of them here and there. There is a chance they recently molted and are hiding, sometimes happens after a water change, a bunch will molt around the same time and hide for a few days. But also they could have become snack food as well.
My hopes are you find them. When they are grown adults, there would be less chance of them becoming snacks. But when they are small, young, in my case they were appx. the size of dwarf shrimp, a few a little bit larger. Still small.
What are you water parameters, are they good for Amano shrimp? And as a side note, yes they are touted as algae eating shrimp. BUT they are shrimp, not vegetarians either, scavengers, which definitely like a good meal, and meaty food included. Having a good shrimp food with minerals for molting is important. If you happen to find a few of them hiding around the tank a basic inexpensive food would be Hikari Crab Cuisine. If there are a good number, I would suggest finding a shrimp food. I like a few brands but Glasgarten Shrimp Fit is good, and they have a product called Mineral Junkie which is little mineral balls also great for snails and shrimps. There are dried leaves Indian Almond, banana, Guava, Mulberry, pelleted foods are made from these too, they love them and nettles, which they love to munch because they develop a biofilm and begin to break down provide more food.
Good wishes for getting a good combinaton of shrimp and fish.
Other possibility is that they are hiding underneath something.
