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.
Highlights
Tardigrades are a phylum of globally distributed microinvertebrates which inhabit terrestrial and marine habitats (Nelson et al 2015)
We found two species of the Macrobiotus hufelandi group, one new to science and the other conforming to the description of Macrobiotus recens Cuénot, 1932
We provide taxonomic descriptions based on morphological and morphometric data acquired with phase contrast light microscopy (PCM) as well as from scanning electron microscopy (SEM)
Summary
Tardigrades are a phylum of globally distributed microinvertebrates which inhabit terrestrial and marine habitats (Nelson et al 2015). Tardigrade faunistic studies have been conducted for more than two centuries, many regions are still very poorly known in terms of tardigrade species composition. One such place is the Canary Islands (Spain), where only two studies on tardigrades. 13 taxa identified to species level have been reported from the Canary Islands: Echiniscus arctomys Ehrenberg, 1853, E. canadensis Murray, 1910, E. quadrispinosus Richters, 1902, E. mediantus Marcus, 1930, E. trisetosus Cuénot, 1932, Isohypsibius tuberculatus (Plate, 1888), Macrobiotus echinogenitus Richters, 1904, M. furcatus Ehrenberg, 1859, M. hufelandi C.A.S. Schultze, 1834, M. occidentalis Murray, 1910, Milnesium tardigradum Doyère, 1840, Minibiotus intermedius (Plate, 1888) and M. gumersindoi Guil & Guidetti, 2005. Records of M. hufelandi and M. tardigradum predate the redescriptions of these species (Bertolani & Rebecchi 1993 and Michalczyk et al 2012, respectively), and they need to be verified against modern literature
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
