Abstract
Species boundaries are difficult to establish in groups with very
similar morphology. As an alternative, it has been suggested to
integrate multiple sources of data to clarify taxonomic problems in taxa
where cryptic speciation processes have been reported. This is the case
of the harvest mouse Reithrodontomys mexicanus, which has a
problematic taxonomy history as it is considered a complex species.
Here, we evaluate the cryptic diversity of R. mexicanus using an
integrative taxonomy approach in order to detect candidate lineages at
the species-level. The molecular analysis used one mitochondrial (cytb)
and two nuclear (Fgb-I7 and IRBP) genes. Species hypotheses were
suggested based on three molecular delimitation methods (mPTP, bGMYC,
and STACEY), and cytb genetic distances values. Skull and environmental
space differences between the delimited species were also tested to
complement the discrimination of candidate species. Based on the
consensus across the delimitation methods and genetic distance values,
four species were proposed, which were mostly supported by morphometric
and ecological data: R. mexicanus clade I, R. mexicanus
clade IIA, R. mexicanus clade IIIA, and R. mexicanus clade
IIIB. In addition, the evolutionary relationships between the species
that comprise the R. mexicanus group were discussed from a
phylogenetic approach. Our findings present important taxonomic
implications for Reithrodontomys, as the number of known species
for this genus increases. Furthermore, we highlight the importance of
the use of multiple sources of data in systematic studies to establish
robust delimitations between species considered taxonomically complex.