A new species of cloud fish of the genus Cynolebias (Cyprinodontiformes: Rivulidae) from the upper rio Jaguaribe basin, in the Brazilian semiarid

In 2021, through the social media, a new record of Cynolebias was reported in the upper rio Jaguaribe basin in Ceará State (CE), northeastern Brazil. Previously, Cynolebias microphthalmus was the only species of the genus from the Northeastern Caatinga and Coastal Drainages hydrographic ecoregion, known from the seasonal pools of the rio Apodi-Mossoró basin in Rio Grande do Norte State and in the lower rio Jaguaribe basin (CE).

Based on morphological and molecular data (mitochondrial DNA sequences), we concluded that the recent record represents a new species, described herein as Cynolebias penaforte sp. nov. . It differs from all congeners by absence of contact organs on inner surface pectoral fin-rays in males, and by presenting higher number of supraorbital scales, dorsal-fin origin through base of 8 th anal-fin ray, and higher number of neuromasts in anterior rostral, otic, and post-otic series.

The new species was only recorded in a temporary pool close to the rio São Francisco inter-basin water transfer channels, highlighting the possible impact of changes in the hydrologic cycles to the Brazilian semiarid seasonal killifishes. Finally, the description of this species was only possible due to the citizen science provided by two residents of the municipality in which the species was discovered.