Cognettia varisetosa (Martinsson, Rota & Erséus, 2015)

(Figure 15)

Material examined. 8 specimens (two specimens were deposited in the National Institute of Biological Resources, Korea; NIBRIV0000837800, slide No. 2570) .

This species mostly reproduces by fragmentation, and this asexual reproduction is relatively fast, therefore observing sexually adult specimens is not always possible. We found only juvenile and subadult specimens, but based on the molecular analysis they are identical with C. varisetosa (see below). Length of 20 anteriormost segments 2.8–5 μm and width 260–300 μm. Worms have 3–4 pair primary and 3–4 secondary pharyngeal glands (Figs 15A, B). Chaetae sigmoid without nodulus, mostly 3 chaetae in a bundle, except some lateral preclitellar bundles which have 2 chaetae. Brain slightly concave posteriorly (Fig. 15C). Dorsal blood vessel arising in XIV–XV. First pair of nephridia at 8/9 or 9/10, efferent duct originating antero-ventrally, anteseptale consisting of funnel only. Sperm funnels were not observable. Spermathecae paired, ectal duct long with rounded glands at orifice.Ampullae oval, about 45 μm wide. Ampulla followed by a duct connecting to an ental chamber, 50 μm wide (Fig. 15D, E). Spermathecae not connected to oesophagus.

Distribution and habitat in Korea. Mt. Gyebangsan, Nodong-ri, Yongpyeong-myeon, Pyeongchang-gun, Gangwon-do, Q. mongolica forest, N 37°42’27.92”, E 128°29’02.34”, 848 m asl.