Misidentification of Gymnotus interruptus (Gymnotiformes: Gymnotidae) leads to erroneous karyotype addressing

Cytogenetic Gymnotidae Gymnotus bahianus Knifefish Sex Chromosome.


  • Filipe Silva Rangel-Pereira Laboratório de Sistemática e Evoluí§ào de Peixes Teleósteos, Departamento de Zoologia, Universidade Federal do Rio de Janeiro, Caixa Postal 68049, CEP 21944-970, Rio de Janeiro, RJ, Brazil.
  • Felipe Polivanov Ottoni Universidade Federal do Maranhào, Laboratório de Sistemática e Ecologia de Organismos Aquáticos, Centro de Ciíªncias Agrárias e Ambientais (CCAA), Campus de Chapadinha, BR-222, KM 04, S/N, Boa Vista, CEP 65500-000, Chapadinha, MA, Brazil.
December 21, 2020


Recently an article entitled "A unique sex chromosome system in the Knifefish Gymnotus bahianus with inferences about chromosomal evolution of Gymnotidae" has presented the chromosomal structure of a Gymnotus population inhabiting the Contas River basin, eastern Brazil. We believed that the examined specimens were misidentified as G. bahianus. Hence in this work we examined the used material of the above-mentioned work and found that they belong to the species G. interruptus. This conclusion was based on a careful examination of materials from both species (type, recently collected, and additional materials). Gymnotus interruptus can be distinguished from G. bahianus by possessing a colouration pattern in which conspicuous dark obliquely oriented bands occur under lateral line at entire extension of trunk.