taxonID	type	description	language	source
03B31230FFDFAB788FCDFC1FFCAF4AC8.taxon	diagnosis	Diagnosis: (modified from Fonseca & Bezerra, 2014) Cuticle striated. Inner labial sensilla papilliform; outer labial and cephalic setae at the same circle of variable length. Additional subcephalic setae might be present. Amphids circular. Buccal cavity conical or funnel-shaped, weakly sclerotized. Cardia small, surrounded by intestine. Ventral gland absent. Post- and pre-vulval sac may be present. Spicules mostly short and strongly curved or L-shaped. Gubernaculum mostly present with lateral guiding pieces and sometimes with dorso-caudal apophysis. Tail conico-cylindrical with two (rarely three or four) terminal setae.	en	Li, Ting, Ban, Shuyan, Huang, Yong (2023): Two new species of Xyalidae Chitwood, 1951 (Nematoda, Monhysterida) from Chinese Sea Area. Zootaxa 5369 (2): 255-268, DOI: 10.11646/zootaxa.5369.2.5, URL: https://www.mapress.com/zt/article/download/zootaxa.5369.2.5/52241
03B31230FFDFAB7C8FCDFB66FAA14F0C.taxon	description	(Figures 1 – 2, Table 1)	en	Li, Ting, Ban, Shuyan, Huang, Yong (2023): Two new species of Xyalidae Chitwood, 1951 (Nematoda, Monhysterida) from Chinese Sea Area. Zootaxa 5369 (2): 255-268, DOI: 10.11646/zootaxa.5369.2.5, URL: https://www.mapress.com/zt/article/download/zootaxa.5369.2.5/52241
03B31230FFDFAB7C8FCDFB66FAA14F0C.taxon	materials_examined	Holotype and paratype material. Four males and two females were obtained and measured. Holotype male on slide HDYST N 88 - 11. Paratype 1 (male) on slide HDYST N 54 - 2 - 3, paratype 2 (male) on slide HDYST N 54 - 1 - 18, paratype 3 (male) on slide HDYST 1 - 12, paratype 4 (female) on slide HDYST N 54 - 3 - 8 and paratype 5 (female) on slide HDYST N 54 - 1 - 8. Type locality and habitat. Holotype and paratypes were all collected from intertidal fine sandy sediments at Huangdao Silver Beach (120 ° 12 ′ 3 ′′ E, 35 ° 55 ′ 8 ′′ N) in May 2021.	en	Li, Ting, Ban, Shuyan, Huang, Yong (2023): Two new species of Xyalidae Chitwood, 1951 (Nematoda, Monhysterida) from Chinese Sea Area. Zootaxa 5369 (2): 255-268, DOI: 10.11646/zootaxa.5369.2.5, URL: https://www.mapress.com/zt/article/download/zootaxa.5369.2.5/52241
03B31230FFDFAB7C8FCDFB66FAA14F0C.taxon	etymology	Etymology. The species epithet refers to the country of origin, China.	en	Li, Ting, Ban, Shuyan, Huang, Yong (2023): Two new species of Xyalidae Chitwood, 1951 (Nematoda, Monhysterida) from Chinese Sea Area. Zootaxa 5369 (2): 255-268, DOI: 10.11646/zootaxa.5369.2.5, URL: https://www.mapress.com/zt/article/download/zootaxa.5369.2.5/52241
03B31230FFDFAB7C8FCDFB66FAA14F0C.taxon	description	Measurements. All measurement data are given in Table 1. Description. Males. Body slender. Anterior end hemispherical with six spherical lips. Cuticle transversely striated. Somatic setae sparsely distributed throughout the body, 6 – 8 μm long. Inner labial sensilla papilliform. Outer labial setae and cephalic setae united in one circle and total 12 setae. Outer labial setae 6 – 8 μm long, cephalic setae 13 – 17 μm long or 87 % – 89 % of the corresponding body diameter. Amphidial fovea circular, 8 μm in diameter, occupying 31 % – 35 % of the corresponding body diameter, posterior to the buccal cavity (20 – 22 μm or 1.2 – 1.5 head diameter from anterior end). Buccal cavity broad, funnel-shaped. Pharynx cylindrical, not enlarged at base. Cardia conical, 13 μm long, surrounded with intestinal tissue. Nerve ring at the middle of pharyngeal length. Ventral gland and excretory pore not observed. Tail conico-cylindrical with cylindrical posterior half and two terminal setae, 5.2 – 5.6 cloacal body diameters long. Three caudal glands well developed. Reproductive system diorchic with two opposed testes. Spicules slender, bending into a hook shape in the posterior half, 28 – 29 μm long (about 1.2 – 1.4 times of the cloacal body diameter), proximal end cephalated and distal end pointed. Gubernaculum small and simple, plate-like, without apophysis, parallel to the distal end of spicules. Females. Similar to males in morphologic characteristics, except tail relatively longer (c′ = 5.6 – 6.7 versus 5.2 – 5.6). Reproductive system monodelphic, ovary outstretched, located on left side of intestine. Vulva located at 70 % – 82 % of total body length from anterior end. Post-vulval sac absent.	en	Li, Ting, Ban, Shuyan, Huang, Yong (2023): Two new species of Xyalidae Chitwood, 1951 (Nematoda, Monhysterida) from Chinese Sea Area. Zootaxa 5369 (2): 255-268, DOI: 10.11646/zootaxa.5369.2.5, URL: https://www.mapress.com/zt/article/download/zootaxa.5369.2.5/52241
03B31230FFDFAB7C8FCDFB66FAA14F0C.taxon	diagnosis	Differential diagnosis and discussion. Daptonema sinica sp. nov. is characterised by relatively large body with broad funnel-shaped buccal cavity; relatively long cephalic setae in the genus; circular amphidial fovea posterior to the buccal cavity, slender spicules bending into a hook shape in the posterior half; small and simple gubernaculum without apophysis; slender conico-cylindrical tail with two terminal setae. In having similar spicules shape and gubernaculum without apophysis, the new species is simillar to D. fallax (Lorenzen, 1971) Lorenzen, 1977, D. microspiculum (Gerlach, 1953) Lorenzen, 1977 and D. oxycerca (de Man, 1888) Lorenzen, 1977. The new species differs from D. fallax by longer spicules (29 μm versus 19 μm), smaller amphidial fovea (31 % – 35 % versus 80 % of the corresponding body diameter) and shorter tail (c = 9.5 – 12.8 versus 6.2 – 6.8). In addition, the latter species is characterized by a complex gubernaculum and numerous somatic setae. The new species differs from D. microspiculum by longer and slender body (1220 – 1583 μm long and a = 43.6 – 48.0 versus 740 – 914 μm and a = 24 – 31) and more anterior position of amphidial fovea (1.1 – 1.5 versus 2.5 head diameter from anterior end). The new species differs from D. oxycerca by relatively longer cephalic setae (13 – 19 μm versus 7 – 11 μm), shorter spicules without tooth distally (28 – 29 μm versus 57 – 83 μm), gubernaculum plate-like parallel to the distal end of spicules (versus tubular, surrounding distal end of spicules). D. sinica sp. nov. differs from its other congeners in the genus by combination of characters of broad funnel-shaped buccal cavity, relatively long cephalic setae (13 – 19 μm long), amphidial fovea posterior to buccal cavity, slender spicules bending into a hook shape in the posterior half, small and plate-like gubernaculum without apophysis and slender conico-cylindrical tail.	en	Li, Ting, Ban, Shuyan, Huang, Yong (2023): Two new species of Xyalidae Chitwood, 1951 (Nematoda, Monhysterida) from Chinese Sea Area. Zootaxa 5369 (2): 255-268, DOI: 10.11646/zootaxa.5369.2.5, URL: https://www.mapress.com/zt/article/download/zootaxa.5369.2.5/52241
03B31230FFDBAB7C8FCDFE3BFB684D8C.taxon	diagnosis	Diagnosis: (emended from Fonseca & Bezerra, 2014) Cuticle finely striated with brownish appearance. Somatic setae scattered along the body. Inner labial sensilla setiform. Outer labial setae and cephalic setae at the same level. Ventrolateral setae between the labial and cephalic setae usually present. Amphids circular. Buccal cavity extended, divided into two parts by an annule; anterior part cylindrical, posterior part conical. Two gonads; anterior to the left of intestine, posterior to the right. Spicules curved and proximally cephalated. Gubernaculum without apophyses. Three caudal glands opening at separate pores. Tail conical or conico-cylindrical with or without terminal setae. The genus is very similar to Daptonema. Some Metadesmolaimus species have only a slightly extended buccal cavity while several Daptonema species also seem to have a slightly extended buccal cavity. However, Metadesmolaimus species possess relative wide oral annule in the middle of buccal cavity, while Daptonema species lack distinct intermediate oral annule. Moreover, Metadesmolaimus species have brownish appearance and setiform inner labial sensilla, while Daptonema species lack brownish appearance and inner labial setae, and their inner labial sensilla are papilliform. When assigning a species to the genus Metadesmolaimus, we should base that on a combination of main characters as brownish appearance, setiform inner labial sensilla, buccal cavity extended and divided into two parts by a relatively wide oral annule and gubernaculum without apophysis.	en	Li, Ting, Ban, Shuyan, Huang, Yong (2023): Two new species of Xyalidae Chitwood, 1951 (Nematoda, Monhysterida) from Chinese Sea Area. Zootaxa 5369 (2): 255-268, DOI: 10.11646/zootaxa.5369.2.5, URL: https://www.mapress.com/zt/article/download/zootaxa.5369.2.5/52241
03B31230FFDBAB708FCDFBA3FE844F28.taxon	description	(Figures 3 – 5, Table 2)	en	Li, Ting, Ban, Shuyan, Huang, Yong (2023): Two new species of Xyalidae Chitwood, 1951 (Nematoda, Monhysterida) from Chinese Sea Area. Zootaxa 5369 (2): 255-268, DOI: 10.11646/zootaxa.5369.2.5, URL: https://www.mapress.com/zt/article/download/zootaxa.5369.2.5/52241
03B31230FFDBAB708FCDFBA3FE844F28.taxon	materials_examined	Holotype and paratype material. Four males and two females were obtained and measured. Holotype male on slide YST 86 - 1 - 12. Paratype 1 (male) on slide YST 40 - 1 - 3, paratype 2 (male) on slide WWJT 35 - 1 - 8, paratype 3 (male) on slide WWJT 186 - 2 - 6, paratype 4 (female) on slide WWJT 58 - 1 - 6 and paratype 5 (female) on slide WWJT 186 - 1 - 5. Type locality and habitat. Holotype and paratypes were all collected from intertidal fine sandy sediments at Beihai Silver Beach in the Beibu Gulf of the South China Sea (109 ° 44 ′ 49 ′′ E, 21 ° 14 ′ 42 ′′ N) in February 2021.	en	Li, Ting, Ban, Shuyan, Huang, Yong (2023): Two new species of Xyalidae Chitwood, 1951 (Nematoda, Monhysterida) from Chinese Sea Area. Zootaxa 5369 (2): 255-268, DOI: 10.11646/zootaxa.5369.2.5, URL: https://www.mapress.com/zt/article/download/zootaxa.5369.2.5/52241
03B31230FFDBAB708FCDFBA3FE844F28.taxon	etymology	Etymology. The species epithet is derived from the Latin bulbosus, meaning polyglobular, referring to its prominent bulb-like muscular swellings in the pharynx.	en	Li, Ting, Ban, Shuyan, Huang, Yong (2023): Two new species of Xyalidae Chitwood, 1951 (Nematoda, Monhysterida) from Chinese Sea Area. Zootaxa 5369 (2): 255-268, DOI: 10.11646/zootaxa.5369.2.5, URL: https://www.mapress.com/zt/article/download/zootaxa.5369.2.5/52241
03B31230FFDBAB708FCDFBA3FE844F28.taxon	description	Measurements. All measurement data are given in Table 2. Description. Males. Body cylindrical, brownish (Figure 5). Cuticle transversely striated, about 1 µm between two striations. Lips high, with six inner labial setae, 4 – 6 µm long. Six outer labial setae and four cephalic setae arranged in one circle. Outer labial setae 17 – 19 µm long; cephalic setae 9 – 12 µm long. Numerous long somatic setae in pharyngeal region, 20 – 35 µm long. Amphids difficult to distinguish, circular, 7 µm in diameter (27 % of the corresponding body diameter), situated posterior to the buccal cavity, about 24 µm from anterior end. Buccal cavity broad, extended anteriorly with an intermediate annule; anterior part cylindrical, posterior part conical, 22 µm deep and 15 µm wide. Pharynx cylindrical, with a series (18) of bulb-like muscular swellings, each with thick cuticular lining, 8 – 16 µm long and 17 – 19 µm wide. The adjacent pharyngeal bulbar swellings separated by transverse elliptic dilated structures and internal lumen. Cardia large, conical, 13 µm long. Nerve ring located at 33 % – 42 % of the pharynx length from anterior end. Excretory pore and ventral gland not observed. Tail narrowing abruptly immediately posterior to cloaca; conico-cylindrical, 5.6 – 6.2 times cloacal body diameter, with several short setae. Tail tip slightly swollen, bearing two terminal setae, 10 µm long. Reproductive system diorchic with two opposed testes, anterior testis situated to the left of intestine, posterior testis to the right. Spicules almost straight, clavated, 1.8 – 1.9 times cloacal body diameter in length, with broad proximal end and hooked distal end. Gubernaculum absent. Females. Similar to males in general characteristics, except body relatively thicker (a = 27 – 28.6 versus 37.9 – 42.7), as well as buccal cavity also larger (27 – 30 µm versus 20 – 22 µm in width and 20 – 23 µm versus 15 – 17 µm in depth). Reproductive system monodelphic, ovary outstretched, reaching the base of the pharynx, located left of intestine. Post-vulval sac present, with a spermatheca. Vulva located in two thirds of the body length from anterior body extremity.	en	Li, Ting, Ban, Shuyan, Huang, Yong (2023): Two new species of Xyalidae Chitwood, 1951 (Nematoda, Monhysterida) from Chinese Sea Area. Zootaxa 5369 (2): 255-268, DOI: 10.11646/zootaxa.5369.2.5, URL: https://www.mapress.com/zt/article/download/zootaxa.5369.2.5/52241
03B31230FFDBAB708FCDFBA3FE844F28.taxon	diagnosis	Differential diagnosis and discussion. Metadesmolaimus bulbosus sp. nov. is characterized by large buccal cavity, long cervical setae, 18 bulb-like pharyngeal muscular swellings, conico-cylindrical tail narrowing abruptly immediately posterior to cloaca, straight clavated spicules with expanded proximal end and hooked distal end and gubernaculum absent. The new species is similar to M. zhanggi Guo, Chen & Liu, 2016 in having long somatic setae in pharynx region and narrow conico-cylindrical tail. However, it can be distinguished in several aspects. It differs from M. zhanggi by longer and slender body in males (1326 – 1456 µm and a = 37.9 – 42.7 versus 930 – 981 µm and a = 26.2 – 30.6), slender and not jointed outer labial setae (versus stout and jointed), narrower and longer tail (5.4 – 6.2 versus 4.3 – 5.3 cloacal body diameter), straight and clavated spicules with hooked distal end versus L-shaped spicules with pointed distal end. M. bulbosus sp. nov. differs from its other congeners by a combination of characters of multiple pharyngeal bulb-like swellings, abruptly narrowed tail, clavated spicules with expanded proximal end and hooked distal end. In addition, M. bulbosus sp. nov. is similar to Daptonema fallax (Lorenzen, 1971) Lorenzen, 1977 and D. robustum (Tchesunov, 1980) Tchesunov, 1990 in having large buccal cavity. However, in D. fallax, the buccal cavity lacks annule and spicules are curved and double-bent in the distal half. In D. robustum, anterior part of buccal cavity is conical, not cylindrical, the inner labial sensilla is not setiform and the gubernaculum has apophysis. The tail of M. bulbosus sp. nov. is similar to Daptonema furcatum (Juario, 1974) Lorenzen, 1977, but the buccal cavity of the latter species is not extended, inner labial sensilla is not setiform, spicules are S-shaped and gubernaculum has apophysis. The difference between M. bulbosus sp. nov. and its other congeners within Metadesmolaimus can be inferred from the key below.	en	Li, Ting, Ban, Shuyan, Huang, Yong (2023): Two new species of Xyalidae Chitwood, 1951 (Nematoda, Monhysterida) from Chinese Sea Area. Zootaxa 5369 (2): 255-268, DOI: 10.11646/zootaxa.5369.2.5, URL: https://www.mapress.com/zt/article/download/zootaxa.5369.2.5/52241
