Pseudorestias lirimensis, found in the Chilean Altiplano, represents a new species and genus of killifish (order Cyprinodontiformes).
A total of 26 fish from the Chancacolla River and Charvinto Creek were collected for this study. Physical data was collected for 20 of these. Genetic material from five of these was analysed. The sex of each fish was also recorded.
A few physical differences between the sexes were found. For example. females were found to be elongated. They also had a neuromast (sensory organ) pattern not found in males. This differs from species of the genus Orestias (a genus of pupfish in Cyprinodontiformes).
Genetic analysis showed that both males and females had a chromosome number of 48, which is often seen in the family Cyprinodontidae. The structure of the chromosomes differed from those seen in the genus Orestias.
The authors have proposed a IUCN Red List category of critically endangered for Pseudorestias lirimensis. This is due to its limited range (less than 100 km²), water demands in the region and climate change.
The original paper can be found here.