Species-Specific Diversity of a Fixed Motor Pattern: The Electric Organ Discharge of Gymnotus

Proximate and ultimate causes of signal diversity in the electric fish Gymnotus.

A complete understanding of animal signal evolution necessitates analyses of both the proximate (e.g. anatomical and physiological) mechanisms of signal generation and reception, and the ultimate (i.e. evolutionary) mechanisms underlying adaptation and diversification. Here we summarize the results of a synthetic study of electric diversity in the species-rich neotropical electric fish genus Gy...

Waveform diversity of electric organ discharges: the role of electric organ auto-excitability in Gymnotus spp.

This article shows that differences in the waveforms of the electric organ discharges (EODs) from two taxa are due to the different responsiveness of their electric organs (EOs) to their previous activity (auto-excitability). We compared Gymnotus omarorum endemic to Uruguay (35 degrees South, near a big estuary), which has four components in the head to tail electric field (V(1) to V(4)), with ...

Changes in electric organ discharge after pausing the electromotor system of Gymnotus carapo.

During their entire lives, weakly electric fish produce an uninterrupted train of discharges to electrolocate objects and to communicate. In an attempt to learn about activity-dependent processes that might be involved in this ability, the continuous train of discharges of intact Gymnotus carapo was experimentally interrupted to investigate how this pausing affects post-pause electric organ dis...

Nesting and Paternal Care in the Weakly Electric Fish Gymnotus (Gymnotiformes: Gymnotidae) with Descriptions of Larval and Adult Electric Organ Discharges of Two Species

Electric Imaging through Evolution, a Modeling Study of Commonalities and Differences

Modeling the electric field and images in electric fish contributes to a better understanding of the pre-receptor conditioning of electric images. Although the boundary element method has been very successful for calculating images and fields, complex electric organ discharges pose a challenge for active electroreception modeling. We have previously developed a direct method for calculating ele...