Taxonomic Study of Marine Tardigrades from Korea III. A New Species of the Genus Orzeliscus (Heterotardigrada, Halechiniscidae)

Abstract

A new marine tardigrade species of the genus Orzeliscus belonging to the family Halechiniscidae is described from the sea coasts of Korea and Japan. This new species is most characterized in having slender, pole-shaped clava with uniform breadth along its whole length. Furthermore, it evidently differs from the congeners by the combination of characters of a hemispherical protrusion on cheek region of the head, a big and bulbous lateral projection between leg III and leg IV, and an elongate papillus terminating with a minute tube on leg IV. 'Orzeliscus cf. belopus' sensu McKirdy, Schmidt and McGinty-Bayly, 1976 from the Galapagos Islands quite resembles this new species in sharing the slender, pole-shaped clava. However, these two Pacific populations are distinguished to each other by body size and shapes of the protrusion on cheek region and the lateral projection between leg III and leg IV. Scanning electron microscope photographs and a key to species of the genus Orzeliscus are also provided herein.

Application of DNA Barcoding in Taxonomy and Phylogeny: An Individual Case of COI Partial Gene Sequencing from Seven Animal Species

“…Water bears or tardigrades (Parachaela, Macrobiotidae) are small, ubiquitous (less than 1 mm) organisms, which can tolerate a wide range of abiotic parameters in an inactive stage. Th e systematics of the group is under development and a signifi cant number of new species are described every year (Lee et al, 2017;Perez-Pech et al, 2017;Kaczmarek & Michalczyk, 2017;. However, tardigrades are a challenge to taxonomists because of their small size, unknown magnitude of intraspecifi c variation and oft en a lack of experts who are able to identify species.…”