Abstract:
Evolutionarily, changes in social behavior are associated with differences in neural circuitry. Weakly electric fish communicate using stereotyped brief pulses of electricity, distributed non-uniformly over time; called Electric Organ Discharges (EODs). In the Mormyrid family of weakly electric fish, species diversification has been correlated with coordinated changes in the exterolateral nucleus (EL) of the electrocommunication pathway in the brain and in the social behaviors exhibited by these fish. Specifically, previous work has established that evolutionary distinctions in EL(anterior/posterior) are associated with differences in the detection of differences in EOD waveform and some aspects of social behavioral ecology. However, less is known about species differences in the timing and coordination of EODs, especially among groups of fish. Differences in the coordination of EODs over time are likely associated with evolutionary changes in brain regions other than EL, for instance, the cerebellum or pallium.
In this study, we compare two distinct Mormyrid species that we have determined by visual observation to display qualitatively different social behavior: Gnathonemus petersii and Brienomyrus brachyistius. We focus on quantifying and describing their electrocommunication behavior when in pairs and when in larger groups. Prior to data collection, extensive electrode testing was done to optimize the best signal to noise. Moreover, preliminary data collection confirms previous literary work specific to echo-response shape EOD waveforms. We can now begin to develop quantitative descriptions of social behavior and communication and how that differs across species. Once behaviors are defined we will then examine how demands of different social behavior and communication are supported by associated neural circuits and how that also differs across species.
Video: Ange Zuniga-Aleman
Live Poster Session:
Thursday, July 29th 1:15-2:30pm EDT