Taxonomic and Faunistic Novelties on Macrobiotids (Tardigrada: Macrobiotidae) from Neotropical Peripheral Mountain Systems

The Neotropical peripheral mountain systems in Colombia, including the Sierra Nevada de Santa Marta, Montes de María, and Serranía de Piojó, have remained underexplored due mainly to historical armed conflicts. This study focuses on tardigrade diversity, particularly the Macrobiotidae family, in these regions. By reviewing specimens (in collections and newly sampled) from the Sierra Nevada de Santa Marta, and new samples from Montes de María and Serranía de Piojó, this research expands the known geographic distribution of certain species and provides new data and amendments to species descriptions. Four potentially new species are reported: Calcarobiotus (Calcarobiotus) aff. gildae, Macrobiotus aff. ragonesei, Paramacrobiotus aff. centesimus, and Paramacrobiotus aff. gerlachae. Additionally, three new records for Colombia (Macrobiotus ocotensis, Mesobiotus coronatus, and Minibiotus continuus) are documented, increasing the known species for the country from 26 to 29. In addition, some specimens of the type series were reanalyzed, and new characters were found, leading to the addition of taxonomic comments on some Macrobiotidae species and an amendment of the description of Pam. centesimus. This research underscores the need for further studies (e.g. including molecular techniques), but it already contributes to the broader understanding of the unique and high biodiversity rich tropical ecosystems.