First record of an annual endemic fish from a semiarid environment in northeastern Brazil

Studies focusing the biology of annual fish are still scarce, and in the case of threatened species, research, as well as the adoption of protective measures for these populations, are needed. We present herein the first record of Hypsolebias antenori (Cyprinodontiformes: Cynolebiidae) in temporary pools of Lajedo de Soledade, located in a semiarid region, in Northeastern Brazil. Five individuals (two males and three females) were captured in three temporary pools in May 2017. For the capture, a sieve (50 x 50 cm) with a 4 mm of mesh size was used. The males showed a total length ranging from 3.5 to 4.7 cm (average: 4.1 cm) and body mass amplitude between 0.38 to 0.94 g (average: 0.66 g). The females had a total length from 3.5 to 3.9 cm (average: 3.67 cm) and body mass amplitude of 0.55 to 0.70 g (average: 0.64). Considering that the collection area is one of the most important archaeological sites in Brazil, this endemic species of Caatinga demonstrates the importance of conservation of the environment and serves to support the preservation of the present area that is not recognized and registered as cultural and environmental patrimony.Keywords: Karst, Jandaira Formation, Caatinga, temporary pools, Cynolebiidae, Hypsolebias antenori.