First record of Kryptolebias hermaphroditus Costa, 2011 (Cyprinodontiformes: Rivulidae) in the extreme north Atlantic Forest mangroves, Rio Grande do Norte state, Brazil

This study records the first occurrence of Kryptolebias hermaphroditus Costa, 2011 in canals or perennial salty water pools in two mangroves of the Rio Grande do Norte state, in the estuaries of Ceará-Mirim River and Curimataú River. Due to its hermaphroditism and self-fertilization, a unique feature among vertebrates, this species is very important for many biological areas. Kryptolebias hermaphroditus depends on favorable conditions for their development, therefore, human impacts such as shrimp farming and removal of native vegetation from mangroves may affect populations of this species in northeastern Brazil.