Morphological convergences between African and South American electric fishes.

Mormyroid African electric fishes (left column) are facing gymnotiform South American electric fishes (right column) with similar aspects of morphology (such as elongate bodies, extended tube-like snouts, reduced eyes, and/or small mouth sizes). Anterior portion of body shown above small image of whole body (except for Petrocephalus sullivani); electric organ discharge waveform shown for every species (each trace 5 ms in total duration with head-positivity plotted upwards). (A) Mormyrops zanclirostris, 175 mm standard length (SL), Ivindo River, Gabon, (B) Sternarchorhynchus oxyrhynchus, 220 mm total length (TL), Rio Negro, Brazil; (C) Mormyrus proboscirostris, 232 mm standard length, Ubundu, Congo River, D.R. Congo; (D) Rhamphichthys sp., 305 mm TL, Rio Negro, Brazil; (E) Mormyrops anguilloides, 195 mm SL, Yangambi, Congo River, D.R. Congo; (F) Gymnotus sp., 195 mm TL, Rio Negro, Brazil; and (G) Petrocephalus sullivani, Ogooué River, Gabon; (H) Eigenmannia sp., Apure River, Venezuela. Species A–D feed on benthic invertebrates, species E, F are piscivorous, and G, H feed on pelagic invertebrates.