A Johnny Darter is a small benthic fish, therefore it has many interactions with different types of predators because it is very small in size. Two of the many predators include crayfish (Orconectes rusticus) and small mouth bass (Micropterus dolomieni). In a study by Rahel and Stein, 1988, Johnny Darter interactions where measured under different conditions. The control was the shelter use and activity of the Darters without any predatory influence. That control was then used to compare the activity after crayfish and small mouth bass were introduced both separately and together.

When just a crayfish was present the shelter use and activity levels were very similar to that of the control.

When only a small mouth bass was present the darters had a 6% reduced activity rate.

However when both the small mouth bass and the crayfish were present an interesting interaction occurred between the three species. There was a  19% increase in the activity level of the Johnny Darter. The crayfish would displace the darters and as that was happening the small mouth bass would then in turn force the darters under another shelter causing the activity level to increase by that large percentage (Rahel, Stein, 1988).

Johnny Darters are an aggressive fish who exhibit this behavior when other animals such as the crayfish enter their nest sites. This aggressive behavior reduces the amount of predators likely to prey of them and increases the likelihood of finding a mate (Rahel, 1989).

When larger fish, like northern pike for example, are near by Johnny Darters will release chemicals through their secretion cells in the skin. This provides another mild form of protection other than inactivity and shelter use (Smith 1979).