by TFH Magazine on November 11, 2011 at 9:38 am
The scarlet cleaner shrimp has a well-deserved reputation as being the among best cleaner shrimp you can keep in a tank, and therefore they are often recommended for beginners. They are great additions to a tank because they are hardy, will accept prepared foods, and will clean their tankmates as needed. But recent research at the University of Tübingen in Germany has revealed that scarlet cleaners don’t always play nicely with the other children.
Janine Wong and Prof Nico Michiels ran a controlled experiment in which groups of two, three, or four shrimp of about the same size were placed into aquariums with unlimited access to food. In less than two months they found that in groups larger than two, one or more scarlet cleaners were attacked and killed by the others during the night! The upshot for the home aquarist is to make sure to never include more than two scarlet cleaner shrimp in the same tank, just to be on the safe side.