New Indomalayan Nebularmis species (Heterotardigrada: Echiniscidae) provoke a discussion on its intrageneric diversity

Abstract

Recent years have brought undeniable progress in tardigrade taxonomy, and speciose complexes were detected in a number of phylogenetic lineages. The family Echiniscidae is one such lineage; it is one of the most diverse groups of limno-terrestrial tardigrades and can be characterized as having achieved great evolutionary success. In this contribution, using populations representing several species that originated from the Indomalayan region, we reconstructed phylogenetic affinities within Nebularmis, a recently erected genus within the Echiniscus lineage. Nebularmis auratussp. nov. and Nebularmis burmensissp. nov. are described from the Eastern Yoma Mountains and the Shan Hills (Myanmar), Nebularmis bhutanensissp. nov. is described from the Eastern Himalayas (Bhutan), and Nebularmis indicussp. nov. is described from the foothills of the Western Ghats (Goa, India). Moreover, males are reported in populations of the last two species. All known members of the genus can be phenotypically differentiated based on minute details of their dorsal sculpture and claws. Moreover, a very wide tropical distribution is demonstrated for Nebularmis cirinoi, recorded for the first time from islands of the Malay Archipelago. Furthemore, novel morphological, genetic, and geographic data allowed for the clarification of the generic diagnosis. Currently available data favor a scenario under which Nebularmis evolved in Southeast Asia and later dispersed to other regions of the globe.

Two new Bryodelphax Thulin, 1928 species (Heterotardigrada: Echiniscidae) from the Republic of Ireland with comments on the ‘weglarskae group’ and other heterotardigrade taxa, including the controversial genus Bryochoerus Marcus,1936

“…Details of the anus morphology have not been included in modern diagnoses or emendations of terrestrial heterotardigrade taxa (see Guidetti, 2018 and e.g. Gąsiorek et al, 2019a;Gąsiorek et al, 2020b;Degma et al, 2021b;Gąsiorek et al, 2021a;Gąsiorek et al, 2021b). Schuster (1975) and some recent authors have mentioned the anus in species descriptions in general terms e.g.…”

The wealth of shared resources: Improving molecular taxonomy using eDNA and public databases

“…The Tardigrada are a historically undersampled and understudied taxa (Hashimoto et al, 2016;Koutsovoulos et al, 2016;Yoshida et al, 2017). In recent years, following the publication of the first tardigrade reference genomes, tardigrade genomics and proteomics has entered an exciting new era Gąsiorek et al, 2021;Guil et al, 2019;Jørgensen et al, 2018;Murai et al, 2021;Yoshida et al, 2017). However, many basic questions regarding the core systematics of the group remain, including conflicts about the number and distribution of its classes, the monophyletic nature of its classes, and the assignment of species to families and genera Guidetti et al, 2021;Guil et al, 2019;Jørgensen et al, 2010. Owing to their nature as meioscopic limno-terrestrial organisms, many tardigrade samples were collected during the early days of environmental DNA sampling and molecular taxonomy (Blaxter et al, 2005;Nold et al, 2010;Robeson et al, 2009).…”

Integrative description of Paramacrobiotus bengalensis sp. nov. (Tardigrada: Eutardigrada: Macrobiotidae), a new limno-terrestrial tardigrade species from the state of West Bengal, India

“…Among the marine tardigrades from the class Heterotardigrada Marcus, 1927, Stygarctus bradypus Schulz, 1951 has been reported in Andhra Pradesh (Rao & Ganapati 1968), Odisha (Rao 1969(Rao , 1971, and the Andaman and Nicobar Islands (Rao 1975); Stygarctus lambertii Grimaldi de Zio, D'Addabbo Gallo, Morone De Lucia & Daddabbo, 1987 has been reported from the Indian Ocean (Grimaldi de Zio et al 1987), whereas Vishnudattan et al (2021) discovered a new species, Stygarctus keralensis Vishnudattan, Bijoy Nandan, Hansen & Jayachandran, 2021, from Kerala. Among terrestrial heterotardigrades, Nebularmis indicus Gąsiorek, Ciosek & Michalczyk, 2021 was recently discovered in Goa (Gąsiorek et al 2021). From the class Eutardigrada Richters, 1926, Tumanov (2006 reported and described Milnesium longiungue Tumanov, 2006 from Ladakh.…”