Actual State of Knowledge of the Limno-Terrestrial Tardigrade Fauna of the Republic of Argentina and New Genus Assignment for Viridiscus rufoviridis (du Bois-Reymond Marcus, 1944)

Abstract

Limno-terrestrial tardigrades of Argentina had been studied starting in 1908 and for a long time by European researchers, most frequently in the Patagonian region (incl. the Land of Fire). Starting during the 1980s, Claps, Rossi and collaborators published many surveys, studying other regions also, but with taxonomic criteria at that time. Since the 2000s, methodical and continuous studies using more modern criteria, have been carried out at the National University of La Pampa, contributing to the faunistic, taxonomic and ecological knowledge (including new species descriptions). This paper provides a comprehensive list of the limno-terrestrial tardigrade fauna reported from Argentina, with pertinent evaluations, owing to a careful study of every pertinent piece of literature since 1908, also solving some problems of discordance between the main past checklists. Summarizing, 39 genera and 119 species are present; of these, 72 represent records accepted by the literature, while 47 are records questioned in the literature but which represent distinct taxa surely present in Argentina; 14 additional taxa, instead, are clearly dubious. The authors also report the correct genus assignment to Viridiscus rufoviridis (du Bois-Reymond Marcus, 1944), which now becomes Barbaria rufoviridis comb. nov.

Green armoured tardigrades (Echiniscidae: Viridiscus), including a new species from the Southern Nearctic, exemplify problems with tardigrade variability research

“…Recently, new evidence was presented, pointing out possibly large intraspecific variability within Viridiscus , as two morphs were distinguished within V. viridissimus 16 , 17 . Moreover, V. rufoviridis was transferred to Barbaria 25 , rectifying the earlier assignment of this species within the viridis group 18 , 23 , 26 . Consequently, Viridiscus currently comprises five species: V. clavispinosus , V. perviridis , V. viridianus , V. viridis , and V. viridissimus .…”

“…The morphology of Viridiscus spp. was compared with paratypes of V. viridianus and syntypes of V. perviridis (deposited in the Civic Museum of Natural History in Verona and University of Modena and Reggio Emilia, Italy), and original descriptions or redescriptions of species 17,[23][24][25][26] . Slides of V. viridissimus from Tennessee, including the "miraviridis morphotype" ( 16 , synonymised with V. viridissimus by Gąsiorek et al 17 ), were also examined.…”

Tardigrades (Tardigrada) of Colombia: Historical Overview, Distribution, New Records, and an Updated Taxonomic Checklist

“…Species were identified based on original descriptions and diagnoses [24][25][26][27][28][29][30][31][32][33][34][35][36]. Morphometry was performed with Zen 3.5 (blue edition) software, and data were analyzed using templates from the Tardigrada Register [37] (www.tardigrada.net/register (14 February 2023)).…”