<i>Cryphodera guangdongensis</i> n. sp., (Nematoda: Heteroderidae), a new species of cystoid nematode from roots and surrounding soil of <i>Schima superba</i> in Guangdong, China

<i>Cryphodera guangdongensis</i> n. sp. was collected from the soil and roots of <i>Schima superba</i> in Guangdong province, China. The new species is characterised by having a nearly spherical female, with dimensions of length × width = 532.3 (423.8-675.3) × 295.6 (160.0-381.2) μm, stylet length of 35.7 (31.1-42.1) μm, protruding vulval lips, a vulval slit measuring 54.2 (47.4-58.9) μm, an area between the vulva and anus that is flat to concave, and a vulva-anus distance 49.3 (41.1-57.6) μm. The male features two lip annules, a stylet length of 31.7 (27.4-34.8) μm and basal knobs that are slightly projecting anteriorly, while lateral field is areolated with three incisures and spicules length of 27.1 (23.7-31.0) μm. The second stage juvenile is characterised by a body length of 506.1 (441.8-564.4) μm long, two to three lip annules, a stylet length 31.2 (29.7-33.2) μm which is well developed, basal knobs projecting anteriorly, a lateral field that is areolate with three incisures, and a narrow rounded tail measuring 63.2 (54.2-71.3) μm long, with a hyaline region of 35.6 (27.4-56.6) μm long that is longer than the stylet. Based on morphology and morphometrics, the new species is closely related to <i>C. sinensis</i> and <i>C. japonicum</i> within the genus <i>Cryphodera.</i> The phylogenetic trees constructed based on the ITS-rRNA, 28S-rRNA D2-D3 region, and the partial <i>COI</i> gene sequences indicate that the new species clusters with other <i>Cryphodera</i> species but maintains in a separated subgroup. A key to the species of the genus <i>Cryphodera</i> is also provided in this study.