Integrative description of Macrobiotus canaricus sp. nov. with notes on M. recens (Eutardigrada: Macrobiotidae)

Abstract

Abstract. In this paper we describe Macrobiotus canaricus sp. nov., a new tardigrade species of the Macrobiotus hufelandi group from the Canary Islands. Moreover, with the use of DNA sequencing, we confirm that Macrobiotus recens Cuénot, 1932 represents the hufelandi group, even though eggs laid by this species do not exhibit the typical hufelandi group morphology. Our study is based on both classical taxonomic methods that include morphological and morphometric analyses conducted with the use of light and scanning electron microscopy, and on the analysis of nucleotide sequences of four molecular markers (three nuclear: 18S rRNA, 28S rRNA, ITS-2, and one mitochondrial: COI). Our analyses revealed that M. canaricus sp. nov. is most similar to Macrobiotus almadai Fontoura et al., 2008 from the Archipelago of the Azores, from which it differs by the absence of granulation patches on the external and internal surfaces of legs I-III as well as by the absence of a cuticular pore in the centre of the external patch on legs I-III. Molecular sequences allowed us to pinpoint the phylogenetic positions of M. canaricus sp. nov. and M. recens within the M. hufelandi group.

High diversity in species, reproductive modes and distribution within the Paramacrobiotus richtersi complex (Eutardigrada, Macrobiotidae)

“…in Echiniscus and Richtersius ; [8, 13, 63]). To date, the only exception is represented by the amphimictic species Macrobiotus macrocalix Bertolani and Rebecchi [60], identified with a molecular approach in Italy (in Apennines and Alps; [39]), Sweden [39], Poland [64], and Portugal [65], while the morpho-species was also cited in Poland [66], Austria [67], Albania [68], Spain [69], and Seychelles Islands [70]. The difference in distribution between apomictic and amphimictic populations can be explained by the difference in the potential of dispersal associated with the two types of reproduction.…”

Two new species of Tardigrada from moss cushions (Grimmia sp.) in a xerothermic habitat in northeast Tennessee (USA, North America), with the first identification of males in the genus Viridiscus

“…4. ITS-2: 0.5-30.6% (17.2% on average), with the most similar being Macrobiotus canaricus (Stec, Krzywański & Michalczyk, 2018) Michalczyk, 2018) and the least similar being Macrobiotus scoticus Stec et al, 2017 (KY797268) (Stec et al, 2017).…”

When DNA sequence data and morphological results fit together: Phylogenetic position of Crenubiotus within Macrobiotoidea (Eutardigrada) with description of Crenubiotus ruhesteini sp. nov

“…The very small dots on the cuticle surface have previously been noted in Macrobiotus species (e.g., Stec, Krzywański, et al, 2018). They are probably present in several other species but overlooked, being only visible with SEM.…”