A new species of killifish of the family Profundulidae from the highlands of the Mixteca region, Mexico

Abstract

The family Profundulidae is one of the few families of freshwater fishes endemic to the Mesoamerican region. It includes the genus Profundulus that has been divided into two subgenera, Profundulus, with a wider distribution and Tlaloc, which presents a more limited range. The species currently recognized within the subgenus Profundulus are P. punctatus, P. oaxacae, P. guatemalensis and P. kreiseri. Results from a previous study using allozymes revealed a high degree of molecular differentiation of the populations inhabiting the Mixteca region (located at the north of Oaxaca in Mexico), compared to the rest of the species in the genus, especially regarding its geographically nearest neighbor (P. oaxacae). The main goal of this study was to evaluate the morphological distinctiveness and to assess the taxonomic identity of the populations from the Mixteca region in comparison with the morphological variation of P. oaxacae. Based on 22 measurements (17 morphometric and 5 meristic), we examined the morphological variation within and among species, including 50 individuals from 5 localities. Our results show a high degree of morphological differentiation between both populations in accordance to the molecular information reported before, supporting that populations from the Mixteca region are a new taxonomic entity, which is described in the present study.