Shrimp are a very good member of the clean up crew. The cleaner shrimp (my fav) will clean parasites off fish such as ich, (but can't cure ich just helps prevent). I also like the peppermint and the camel back shrimp, these are kinda shy but clean up any uneaten food detris and are peacful shrimp, like posted above the coral banded shrimp is aggressive towards other shrimp, it just depens on what shrimp you are talking about.