Laboratory Class Project: Using a Cichlid Fish Display Tank to Teach Students about Complex Behavioral Systems
By Brian C. Nolan

Laboratory activities serve several important functions in undergraduate science education.  For neuroscience majors, an important and sometimes underemphasized tool is the use of behavioral observations to help inform us about the consequences of changes that are occurring on a neuronal level.  To help address this concern, the following laboratory exercise is presented.

The current project tested the prediction that the most dominant fish in a tank of cichlids will have gained the most benefits of its position resulting in the greatest growth and hence, become the largest fish.  More specifically:  (1) is there evidence that a social hierarchy exists among the fish in our tank based on the number of aggressive acts among the four largest fish; (2) if so, does the apparent rank correspond to the size of the fish as predicted by previous studies?  Focal sampling and behavior sampling of aggressive acts between fish were utilized in the data collection.  Collectively, the data suggest a social dominance hierarchy may be in place with the following rank order from highest to lowest:  Fish A > Fish B > Fish D > Fish C.  While the largest (Fish A) seems to be at the top, Fish C ended up being ranked lower than Fish D despite the fact that Fish C is larger.

Overall, the project was considered a success by the instructor and students.  The students offered several suggestions that could improve future versions of this type of project, in particular concerning the process of constructing a poster about the project.  The implications of the data and student learning outcomes are discussed.

Key words: cichlid; dominance hierarchy; behavioral analysis; poster presentation; laboratory group project

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