Living in the Leaf Litter: Integrative Taxonomy of the Trichomycterus nigroauratus Group, a Catfish Clade from an Endangered Tropical Biodiversity Hotspot Supporting Areas of Endemism for Conservation and Two New Species

Mountain ranges of southeastern Brazil shelter a great diversity of endemic species, making the local Atlantic Forest among the most important and endangered biodiversity hotspots in the world, but some fish groups are still little known. The primary focus of the current study is the Trichomycterus nigroauratus group, a catfish clade with species living associated with leaf litter, endemic to the upper and middle Rio Paraiba do Sul basin, with all known species described after 2008. We performed an integrative taxonomic approach combining molecular species delimitation analyses and morphology, which inferred a total of six species, two of which are new and here described, in six disjunct areas. Five areas are coincident with distribution areas of other 11 congeners, supporting areas of endemism. We assessed the conservation status by calculating the extent of occurrence and area of occupancy for each of the 16 species occurring in the five areas of endemism. The Serra da Mantiqueira was considered a biodiversity hotspot for trichomycterine catfishes. The approach followed in this study, combining Integrative Taxonomy to delimit areas of endemism with criteria for assessing conservation status, holds great potential as a method for selecting priority areas for biodiversity conservation.