Zelinkaderes yong sp. Nov. from Korea-the first recording of zelinkaderes (Kinorhyncha: Cyclorhagida) in Asia

Abstract

Background: A new kinorhynch species, Zelinkaderes yong sp. nov., is described from Korea. Results: Zelinkaderes yong sp. nov. is described from coastal, sandy habitats in Korea by means of light and scanning electron microscopic techniques. The new species is characterized by the presence of cuspidate spines in lateroventral positions on segments 2 and 9, ventrolateral positions on segment 5, and lateral accessory positions on segment 8; flexible tiny acicular spines in lateroventral positions on segment 2, more regularsized lateroventral acicular spines on segment 8, and middorsal spines on segments 4, 6, 8, 9, and 11. Females furthermore have acicular spines in middorsal and midlateral positions on segment 10, whereas males have crenulated spines on this segment. The absence of acicular spines in the lateral series of segment 9 makes it easy to distinguish the new species from all previously described congeners. The new species differs most from Zelinkaderes submersus, whereas it is morphologically closest to Zelinkaderes klepali. In regard to the spine patterns, the new species only differs from Z. klepali by its lack of lateroventral acicular spines on segment 9. Conclusions: The finding of a new species of Zelinkaderes in East Asia extends the distributional range of the genus, which suggests that the genus basically could be present anywhere in the world and could be considered as cosmopolitan.