Before each trial, the mussels were removed from water and allowed to "starve" for thirty minutes so as to optimize their desire for nutrients. At the start of each trial, a whole poached starfish with a diameter of 13.2 cm was added to the "test" aquarium with ten mussels, all with visibly open valves. The second aquarium was left as a control, and nothing was added to it. This was performed again with a starfish with a diameter of 12.6 cm. The status of the mussels was noted over these trial, which lasted thirty minutes. The aquariums were cleaned between trials to ensure consistent conditions