02147nas a2200265   4500008004100000022001400041245013300055210006900188260001600257300001100273490000800284520132700292653002601619653002001645653002101665653000801686653001401694653001501708100001801723700002201741700002601763700002301789700002101812856004801833       2026                        eng d  a1055-790300aPhylogenetic reconstruction of African weakly electric fish (Campylomormyrus spp.) is suggestive of ancient introgression events0 aPhylogenetic reconstruction of African weakly electric fish Camp  cJan-01-2026  a1084520 v2143 a<p>The African weakly electric fish genus Campylomormyrus belongs to the species-rich family Mormyridae and comprises 15 described species. Previous species trees that focus on the genus, have included at most ten species. The resulting phylogenies have been used to explain the evolution of the species-specific electrical organ discharge (EOD) and interpreted in the context of sympatric speciation caused by disruptive selection. However, available molecular phylogenies that are focused on the Campylomormyrus genus rely only on a limited number of genetic markers. Here, we used ddRAD sequencing to genotype 65 individuals from twelve Campylomormyrus species and Gnathonemus petersii at more than 8,000 SNPs. We reconstruct a robust species tree that is suggestive of ancient introgression events between different species, which might affect both genetic and trait variability in the genus. Different levels of genetic and EOD diversity in two significant Campylomormyrus clades reveals that i) certain species might be in early stages of their speciation process, ii) that hybridization/introgression occurs in mormyrids and iii) that EOD-related genes could be potential speciation genes. Our genomic approach demonstrates the significance of these findings in understanding the evolution of Campylomormyrus.</p>
10aAncient introgression10aCampylomormyrus10addRAD sequencing10aEOD10aphylogeny10aspeciation1 aCanitz, Julia1 aKirschbaum, Frank1 aVendrami, David, L.J.1 aMamonekene, Victor1 aTiedemann, Ralph  uhttps://doi.org/10.1016/j.ympev.2025.10845202770nas a2200181   4500008004100000245017600041210006900217260002000286300001400306490000800320520210100328100002302429700002502452700002202477700002202499700002102521856004602542       2011                        eng d00aSignal variation and its morphological correlates in Paramormyrops kingsleyae provide insight into the evolution of electrogenic signal diversity in mormyrid electric fish0 aSignal variation and its morphological correlates in Paramormyro  bSpringer-Verlag  a799–8170 v1973 a<p>We describe patterns of geographic variation in electric signal waveforms among populations of the mormyrid electric fish species Paramormyrops kingsleyae. This analysis includes study of electric organs and electric organ discharge (EOD) signals from 553 specimens collected from 12 localities in Gabon, West-Central Africa from 1998 to 2009. We measured time, slope, and voltage values from nine defined EOD &ldquo;landmarks&rdquo; and determined peak spectral frequencies from each waveform; these data were subjected to principal components analysis. The majority of variation in EODs is explained by two factors: the first related to EOD duration, the second related to the magnitude of the weak head-negative pre-potential, P0. Both factors varied clinally across Gabon. EODs are shorter in eastern Gabon and longer in western Gabon. Peak P0 is slightly larger in northern Gabon and smaller in southern Gabon. P0 in the EOD is due to the presence of penetrating-stalked (Pa) electrocytes in the electric organ while absence is due to the presence of non-penetrating stalked electrocytes (NPp). Across Gabon, the majority of P. kingsleyae populations surveyed have only individuals with P0-present EODs and Pa electrocytes. We discovered two geographically distinct populations, isolated from others by barriers to migration, where all individuals have P0-absent EODs with NPp electrocytes. At two sites along a boundary between P0-absent and P0-present populations, P0-absent and P0-present individuals were found in sympatry; specimens collected there had electric organs of intermediate morphology. This pattern of geographic variation in EODs is considered in the context of current phylogenetic work. Multiple independent paedomorphic losses of penetrating stalked electrocytes have occurred within five Paramormyrops species and seven genera of mormyrids. We suggest that this key anatomical feature in EOD signal evolution may be under a simple mechanism of genetic control, and may be easily influenced by selection or drift throughout the evolutionary history of mormyrids.</p>
1 aGallant, Jason, R.1 aArnegard, Matthew, E1 aSullivan, John, P1 aCarlson, Bruce, A1 aHopkins, Carl, D  uhttps://doi.org/10.1007/s00359-011-0643-8