Back in 2015, I published a post about experimentation (not experimentation in the scientific sense) in which I highlighted the fact that a lot is going on with respect to your tank water, whether you can see it or not. While I wasn't specifically referring to cichlid communication, cichlids do communicate using chemical cues.
An interesting paper regarding cichlid urination and communication was published online last week in the academic journal Behavioral Ecology and Sociobiology (the paper is also in the February edition of the print version of the journal). Experimenting with Neolamprologus pulcher (commonly called the Daffodil cichlid) from Lake Tanganyika, the authors discovered that these cichlids use urination to signal aggression.
Here is the significance statement from the journal article:
The communication of aggressive tendencies can be achieved by transmitting visual, acoustical and chemical information. In this context chemical communication received less attention than other modalities thus far. We studied the importance of chemical information released via urine during agonistic encounters in the cooperatively breeding cichlid N. pulcher. Using dye injections, we measured urination patterns as well as the aggressive and submissive behaviours of two contestants. We show that N. pulcher actively signals aggressive tendencies via altered urination patterns. Furthermore, we show that appropriate agonistic responses appear to be dependent on the availability of such chemical information. Thus, our results suggest that chemical communication plays a crucial role in multimodal communication of aggression in these fish. These findings highlight the importance of chemical communication during agonistic encounters in general, even if other signals are more obvious to the human observer.
Here is the citation for the article: Bayani, DM., Taborsky, M. & Frommen, J.G. Behav Ecol Sociobiol (2017) 71: 37. doi:10.1007/s00265-016-2260-6
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