First record of a male of Kryptolebias hermaphroditus Costa, 2011 (Cyprinodontiformes: Cynolebiidae)

ABSTRACT

During an ichthyological survey in September 2015 at the Ceará-Mirim River estuary, Rio Grande do Norte State, northeastern Brazil, we collected a male of Kryptolebias hermaphroditus , a cynolebiid species that had been previously described as containing exclusively self-fertilizing hermaphrodites. This is the first record of a male in this species, over 140 years after the discovery of the mangrove rivulid species from Brazil. Our discovery reinforces the need for more studies in K. hermaphroditus , as well as the potential of this species as a model for evolutionary studies due to its unique mating system.

Keywords:
Hermaphroditism; Mangrove killifish; Mid-Northeastern Caatinga ecoregion; Mixed-mating system; Sexual dimorphism