Data from: Phylogenomic species delimitation dramatically reduces species diversity in an Antarctic adaptive radiation

Application of genetic data to species delimitation often builds
confidence in delimitations previously hypothesized using morphological,
ecological, and geographic data and frequently yields recognition of
previously-undescribed cryptic diversity. However, a recent critique of
genomic data-based species delimitation approaches is that they have the
potential to conflate population structure with species diversity,
resulting in taxonomic oversplitting. The need for an integrative approach
to species delimitation, in which molecular, morphological, ecological,
and geographic lines of evidence are evaluated together, is becoming
increasingly apparent. Here, we integrate phylogenetic, population
genetic, and coalescent analyses of genome-wide sequence data with
investigation of variation in multiple morphological traits to delimit
species within the Antarctic barbeled plunderfishes (Artedidraconidae:
Pogonophryne). Pogonophryne currently comprises 29 valid species, most of
which are distinguished solely by variation in ornamentation of the mental
barbel that projects from the lower jaw, a structure previously shown to
vary widely within a single species. However, our genomic and phenotypic
analyses result in a dramatic reduction in the number of distinct species
recognized within the clade, providing evidence to support the recognition
of no more than six species. We propose to synonymize 24 of the currently
recognized species with five species of Pogonophryne. We find genomic and
phenotypic evidence for a new species of Pogonophryne from specimens
collected in the Ross Sea. Our findings represent a rare example in which
application of molecular data provides evidence of taxonomic oversplitting
on the basis of morphology, clearly demonstrating the utility of an
integrative species delimitation framework.