Tardigrades of North America: more new records of occurrence for species of green tardigrades (Heterotardigrada: Echiniscoidea: Echiniscidae: <i>Viridiscus</i>)

Green pigmented tardigrades known as Viridiscus (Heterotardigrada: Echiniscoidea: Echiniscidae) are typically found in limnoterrestrial habitats, such as moss and lichens. However, the distribution of this genus in North America has been historically understudied and remains elusive to microbiologists, ecologists, and tardigrade taxonomists. In the last couple years, new state records of Viridiscus spp. in the United States of America (USA) have been documented from Alabama, Florida, Indiana, Tennessee, and Texas. Here we acknowledge the recent reports along with providing new additional USA records to give an update of Viridiscus spp. distribution. Two species of green tardigrades, Viridiscus perviridis and Viridiscus viridissimus, are reported from six locations in Illinois, Iowa, Minnesota, Mississippi, Missouri, and South Dakota. This is the first report of these species from these states and the farthest west that Viridiscus viridissimus has been found in continental North America. Additionally, we utilized polymerase chain reaction, DNA barcoding of the cytochrome oxidase I (COI) mitochondrial marker, a maximum likelihood phylogenetic analysis, and ASAP analysis to confirm the existence of Viridiscus viridissimus in Missouri.