Morphological and genetic diversity in a South American forest-dependent bat

Abstract

The Neotropical realm is vastly known for its richness, being the Amazon one of the main cradles of taxonomic diversity in the region. In the last decades, molecular analyses have been further increasing the number of Amazonian vertebrate species, hidden under traditional taxonomy due to morphological convergence. Bats represent an interesting example, as the number of recognized bat species is continuously expanding with the identification of numerous cryptic taxa. Studies combining different lines of evidence, such as morphometric and molecular approaches, have been playing an important role in addressing knowledge gaps on Neotropical bat diversity. Within the Phyllostomidae family, the dwarf little fruit bat Rhinophylla pumilio is a forest-dependent species, with a disjunct distribution in the Amazonian and Atlantic forests. Moreover, different karyotypes have been recovered across the species distribution, suggesting this might be one more example of cryptic diversity. Here, we test this assumption by identifying geographic patterns of morphological and molecular variation within the species' entire range of distribution. Our results point to an overall morphological and morphometric homogeneity, except between Atlantic Forest and Amazonian specimens, with significant dissimilarity among some cranial characters. Furthermore, genetic data suggest a rapid and recent diversification, with these two lineages most likely corresponding to speciating taxa. Within the Amazonian forest, our molecular analyses also recovered four additional lineages, likely encompassing intraspecific diversity. Furthermore, studies are required to confirm the need for a taxonomic rearrangement.