I just read another interesting research article on cichlid behavior. This one involves aggression behavior of Neolamprologus pulcher and Telmatochromis temporalis. I am quite familiar with the latter, having bred them many times.
This particular research focused on contest behavior for shelter. In other words, two members of each species were pitted against each other (temporalis vs temporalis and pulcher vs pulcher) to determine territorial aggression levels over a single shelter item. I won’t go into the research methods used. You can read the paper yourself and see how the study was constructed. The title of the article is “Strategic and tactical fighting decisions in cichlid fishes with divergent social systems.” You can find the full reference to the paper at the bottom of the post.
What I found interesting was that the research compared aggression between pair (not breeding pairs) familiarity. In other words, the study consisted of pairs that were already familiar with each other and pairs that were unfamiliar with each other. The results of the temporalis portion were most interesting to me. My opinion, and the same with the authors, is that the results of this particular piece of the study were counterintuitive. I would have expected that aggression levels would be highest among pairs who were unfamiliar with each other. Turns out, it was just the opposite. Familiar pairs had a higher level of aggression. You can read about the multiple ways the researchers measured and coded aggression as well as how they defined “familiarity.”
Reference: Hick, Kristina, Adam R. Reddon, Constance M. O’Connor, and Sigal Balshine. “Strategic and tactical fighting decisions in cichlid fishes with divergent social systems.” Behaviour 151, no. 1 (2014): 47-71.