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G. mamiraua also displayed a distinct karyotypic formula different from its closest relatives. They hypothesized that this could be from chromosomal rearrangements like translocation and pericentric inversion.^[16] This species also has a different NOR (nucleolar organizing region) composition compared to its closest relative, G. cf. mamiraua from the eastern Amazon. They also have evidence that these two populations have different interspacing sequences between ribosomal genes which could be why they may be reproductively isolated due to this karyotypic difference acting as a postzygotic barrier.^[16]

Lastly, when studying G. jonasi they found it has the highest number of st/a (subterminal acrocentric region) chromosomes within its group. They also found that it exhibits multiple NORs which only one other species has. Their study shows just how diverse- in terms of species, electric signals, karyotype, and overall genetics- the Gymnotus family is.^[16]

The findings of the previous study showed that Gymnotus has significant chromosomal diversity^[16] and this is strongly supported by another study. A 2013 study also researched the genus Gymnotus, specifically their electric diversity in the ultimate and proximate perspectives. With the proximate lens, the authors aimed to examine the diversity of EODs and with the ultimate lens they wanted to study signal diversity.^[8] They used 11 species, each representing a major clade. Their results integrated data from multiple fields and dozens of authors and researchers to create a big picture depiction of signal diversity, species diversity, and the evolution of the members of this genus.^[8]

This paper compared three studies about the phylogeny of this genus and concluded that the genus is stable and will not likely change, even with new species that could be discovered in the future with emerging molecular and morphological tests and data.^[8] They found a basal dichotomy between the clade with all remaining Gymnotus species and the G. coatesi clade. The researchers observed several evolutionary ht-EOD structure transitions, too. They also concluded that the ht-EOD differences between closely related Gymnotus species were mostly differences in EOD duration, amplitude, and relative size, all of which oftentimes varied.^[8] In the proximate perspective, this variation correlates to the “diversity in innervation patterns of the electrocytes, auto-excitability, electrocyte density and distribution, and the expression of neurogenic components in the EOD”.^[8] These components show a strong correlation to the ht-EOD structure and phylogenetic signal. In comparison, with the ultimate perspective they found several extrinsic biotic selective pressures that seem to have an effect on the shaping of the communication aspect of EODs.^[8]