Towards a better understanding of echiniscid intraspecific variability: A redescription of Nebularmis reticulatus (Murray, 1905) (Heterotardigrada: Echiniscoidea)

Pseudechiniscus in Japan: re-description of Pseudechiniscus asper Abe et al., 1998 and description of Pseudechiniscus shintai sp. nov.

“…Finally, the ability to confidently describe new Pseudechiniscus species was enabled by the modern diagnosis of P. suillus (Ehrenberg, 1853), one of enigmatic tardigrade taxa described in the 19 th century (Grobys et al 2020). In summary, better understanding of morphology, genetic disparities and ontogenetic shifts (Gąsiorek et al 2019, Morek et al 2019 has facilitated intensification in tardigrade research.…”

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

“…Hashes (#) signify unsupported nodes, the remaining nodes received maximal (1.00) support; C – schematic hypothetical dispersal from Southeast Asia; D – World map shows records (filled symbols) and likely records (empty symbols) of a given Nebularmis species. See [ 28 ] for likely records of N. reticulatus, and the Discussion herein for analogous reports of N. cirinoi …”

“…H. Enghoff, October 1981), and Greenland ([ 36 ], currently deposited in Copenhagen) were used for comparative purposes. Data from Gąsiorek et al [ 28 ] were also utilized. Additionally, we examined specimens of Echiniscus palmai (NZ-381; 1 individual; ca.…”

“…High taxonomic importance was typically assigned to dorsal sculpturing in the Echiniscus lineage [ 24 ]; recently, following the recognition that the phylogenetic position appeared congruent with morphological data, new monophyletic genera were separated from Echiniscus [ 25 , 26 ]. One of these genera, Nebularmis , was created for the widespread Palearctic species Nebularmis reticulatus [ 27 , 28 ] and its kin. These echiniscids exhibit unique dorsal sculpturing that consists of a sponge-like intracuticular layer and large, circular or slightly hexagonal, flat epicuticular granules that may merge, giving the plates an unsculptured appearance, a morphological state unknown in the remainder of the family.…”

“…Such a combination of traits makes Nebularmis easy to recognize; nevertheless, the state of taxonomy within the genus leaves much to be desired. Almost all known Nebularmis species are dubious, most likely synonymous with N. reticulatus [ 28 ], and some other potentially valid species, such as the Neotropical Nebularmis phocae [ 29 ], cannot be identified without redescriptions, as their descriptions are too general. Poor species descriptions continue to be a serious problem when linking the traditionally morphologically based Linnean system of classification with the proliferating use of integrative taxonomic methods [ 30 ], posing difficulties that threaten the stability and reliability of tardigrade systematics [ 31 ].…”