Integrative Descriptions of Two New Tardigrade Species along with the New Record of Mesobiotus skorackii Kaczmarek et al., 2018 from Canada

Abstract

Two new tardigrade species from a moss sample collected in Canada, one representing Macrobiotus hufelandi complex and the second one belonging to the genus Bryodelphax, are described. Integrative analysis was undertaken based on morphological and morphometric data (using both light and scanning electron microscopy (SEM)) combined with multilocus molecular analysis (nuclear sequences, i.e., 18S rRNA, 28S rRNA and ITS-2 as well as mitochondrial COI barcode sequences). Based on COI sequences, Macrobiotus birendrai sp. nov. is most similar to Mac. canaricus (p-distance 17%), whereas Bryodelphax mareki sp. nov. is most similar to Bry. parvulus (p-distance 16%). Both species differ also from their congeners in some morphological and morphometric characters of adults and/or details of egg chorion. Additionally, a large population of Mesobiotus skorackii was found in the sample and this is the first report of this species outside its terra typica in Kirghizia. The original description of this species was prepared based solely on the morphology and morphometry, therefore, here we provide updated data for this species enclosing morphometric and molecular data for the Canadian population.