taxonID	type	description	language	source
F11C878FFB77FB33D985FBE738830D0E.taxon	diagnosis	Diagnosis (emended after Smol et al. 2014) Cuticle with indistinct transverse striations. Lips high. Anterior sensilla in two circles: six inner labial setae large and with bulbous swellings, six outer labial setae very long and four cephalic setae short and thin; amphidial fovea dorsally spiral or oval shaped. Buccal cavity with a pointed, heavily sclerotized dorsal tooth and two less heavily sclerotized ventrosublateral teeth. Males monorchic, testis subventrally left or right of intestine. Precloacal supplements mammiliform or oval shaped. Females with two opposed and reflexed ovaries. Tail conico-cylindrical with terminal setae.	en	Liang, Huixin, Guo, Wen, Wang, Chunming (2024): Two new species of Nematoda: Gairleanema pulchra sp. nov. (Tripyloididae) and Axonolaimus dimorphous sp. nov. (Axonolaimidae) from the Yellow Sea, China. Zootaxa 5447 (4): 547-561, DOI: 10.11646/zootaxa.5447.4.6, URL: http://dx.doi.org/10.11646/zootaxa.5360.3.8
F11C878FFB77FB37D985F9AC3AC00A80.taxon	description	(Figures 1 – 2, Table 1)	en	Liang, Huixin, Guo, Wen, Wang, Chunming (2024): Two new species of Nematoda: Gairleanema pulchra sp. nov. (Tripyloididae) and Axonolaimus dimorphous sp. nov. (Axonolaimidae) from the Yellow Sea, China. Zootaxa 5447 (4): 547-561, DOI: 10.11646/zootaxa.5447.4.6, URL: http://dx.doi.org/10.11646/zootaxa.5360.3.8
F11C878FFB77FB37D985F9AC3AC00A80.taxon	materials_examined	Type material. One male and four females were measured and studied. Holotype: ♂ 1 on 22 SHT 5 – 3 – 6; paratypes: ♀ 1 on 22 RZDT 4 – 1 – 7, ♀ 2 on 22 SHT 5 – 2 – 1, ♀ 3 on 22 RZDT 4 – 3 – 5 and ♀ 4 on 22 RZDT 4 – 2 – 7. Type locality and habitat. Specimens were collected from intertidal muddy sediment at Rizhao coast, Shandong Province, China; 35 ° 23 ′ N, 119 ° 33 ′ E (RZDT), 35 ° 27 ′ N, 119 ° 35 ′ E (SHT); 0 – 8 cm sediment depth.	en	Liang, Huixin, Guo, Wen, Wang, Chunming (2024): Two new species of Nematoda: Gairleanema pulchra sp. nov. (Tripyloididae) and Axonolaimus dimorphous sp. nov. (Axonolaimidae) from the Yellow Sea, China. Zootaxa 5447 (4): 547-561, DOI: 10.11646/zootaxa.5447.4.6, URL: http://dx.doi.org/10.11646/zootaxa.5360.3.8
F11C878FFB77FB37D985F9AC3AC00A80.taxon	etymology	Etymology. Species epithet pulchra refers to beautiful.	en	Liang, Huixin, Guo, Wen, Wang, Chunming (2024): Two new species of Nematoda: Gairleanema pulchra sp. nov. (Tripyloididae) and Axonolaimus dimorphous sp. nov. (Axonolaimidae) from the Yellow Sea, China. Zootaxa 5447 (4): 547-561, DOI: 10.11646/zootaxa.5447.4.6, URL: http://dx.doi.org/10.11646/zootaxa.5360.3.8
F11C878FFB77FB37D985F9AC3AC00A80.taxon	description	Descriptions Male. Cuticle with indistinct transverse striations. Cephalic capsule slightly developed. Three high lips each with a pair of inner labial setae, bulbous swelling about half way along their length. Six long outer labial setae and four short cephalic setae in one circle, somatic setae scarce and present mainly in tail region. Buccal cavity with a large pointed dorsal tooth, two small ventrosublateral teeth, amphidial fovea oval-shaped, 29 μm from anterior end. Pharynx region cylindrical. Nerve ring, 114 μm from anterior end. Cardia triangular. Tail 5.1 cloacal diameters long, posterior half cylindrical. Caudal setae present, 6 – 9 μm in length, and two terminal setae, 16 μm in length. Three caudal glands in line. Reproductive system monorchic, anterior testis to the right of intestine. Spicules L-shaped, proximal end slightly cephalated, 1.1 cloacal diameters along arc. Gubernaculum boat shaped, 25 μm in length, with proximal end hooked anteriorly. One ventral precloacal setae present, 17 μm in length. Seven precloacal supplements oval-shaped, distance between supplements gradually diminishing from the anterior to cloaca. The posterior supplement 29 μm from the cloaca and the anterior supplement 150 μm from the cloaca. Females. Similar to male in most characteristics, but females bodies slightly longer. Caudal setae absent. Reproductive system didelphic, with opposed and reflexed ovaries. Anterior ovary to right of intestine and posterior ovary to left of intestine. Vulva slightly posterior to mid-body.	en	Liang, Huixin, Guo, Wen, Wang, Chunming (2024): Two new species of Nematoda: Gairleanema pulchra sp. nov. (Tripyloididae) and Axonolaimus dimorphous sp. nov. (Axonolaimidae) from the Yellow Sea, China. Zootaxa 5447 (4): 547-561, DOI: 10.11646/zootaxa.5447.4.6, URL: http://dx.doi.org/10.11646/zootaxa.5360.3.8
F11C878FFB77FB37D985F9AC3AC00A80.taxon	diagnosis	Differential diagnosis and discussion. Gairleanema pulchra sp. nov. is characterized by amphidial fovea oval-shaped, spicules L-shaped with proximal end slightly cephalated, gubernaculum boat-shaped with proximal end hooked anteriorly, seven precloacal supplements oval-shaped, supplements distance gradually diminishing from the anterior end to cloaca. Gairleanema pulchra sp. nov. is similar to G. anagremilae in body length and cephalic setae length, but it differs in spicules length and shape (33 μm, without ventral alae vs. 52 – 53 μm, with broad ventral alae), precloacal supplements number and shape (7, oval-shaped vs. 2, mammiliform), gubernaculum shape (boat-shaped with proximal end hooked anteriorly vs. with hooked dorsal apophysis).	en	Liang, Huixin, Guo, Wen, Wang, Chunming (2024): Two new species of Nematoda: Gairleanema pulchra sp. nov. (Tripyloididae) and Axonolaimus dimorphous sp. nov. (Axonolaimidae) from the Yellow Sea, China. Zootaxa 5447 (4): 547-561, DOI: 10.11646/zootaxa.5447.4.6, URL: http://dx.doi.org/10.11646/zootaxa.5360.3.8
F11C878FFB73FB35D985FD0E38FA0AE6.taxon	diagnosis	Diagnosis. (based on Leduc & Zhao 2023) Cuticle finely striated or smooth. Anterior end with four cephalic setae. Cervical setae present, posterior to the amphidial fovea. Amphidial fovea loop-shaped, longitudinally elongated or with rounded outline, at level of buccal cavity. Buccal cavity funnel-shaped, without odontia. Females with two opposed, outstretched ovaries; males with one outstretched testis, sometimes two testes present. Spicules arcuated. Gubernaculum apophysis oriented dorso-caudally. Small tubular or pitlike precloacal supplements sometimes present. Males tail with subventral rows of setae.	en	Liang, Huixin, Guo, Wen, Wang, Chunming (2024): Two new species of Nematoda: Gairleanema pulchra sp. nov. (Tripyloididae) and Axonolaimus dimorphous sp. nov. (Axonolaimidae) from the Yellow Sea, China. Zootaxa 5447 (4): 547-561, DOI: 10.11646/zootaxa.5447.4.6, URL: http://dx.doi.org/10.11646/zootaxa.5360.3.8
F11C878FFB73FB35D985FD0E38FA0AE6.taxon	discussion	Remarks. de Man (1889) erected Axonolaimus with the type species A. spinosus transferred from Anoplostoma, described A. filiformis de Man, 1889 and defined the genus characters as cuticle smooth, head with four cephalic setae, amphidial fovea oval shaped divided by a longitudinal crest, anterior buccal cavity widened and posterior restricted, spicules arcuated and gubernaculum with apophysis, precloacal supplements absent and tail with caudal setae. After de Man (1889), A. limalis Ssaweljev, 1912, A. impar Ssaweljev, 1912 and A. polaris Cobb, 1914 were described. Filipjev (1918) described A. ponticus Filipjev, 1918 and A. setosus Filipjev, 1918 and revised genus characters of amphidial fovea shape, buccal cavity shape and reproduction systems. Afterwards, A. villosus Skwarra, 1922, A. typicus de Man, 1922 and A. antarcticus Cobb, 1930 were described. Schuurmans Stekhoven & Adam (1931) redescribed Anoplostoma spinosus found by de Man (1889) from Walcheren and gave the new name Axonolaimus paraspinosus Schuurmans Stekhoven & Adam, 1931. Axonolaimus similis Schulz, 1932, A. tenuis Schulz, 1932 and A. elegans Schulz, 1932 were later described. De Coninck & Schuurmans Stekhoven (1933) reviewed the unidentified species of Axonolaimus reported by de Man (1928) and named it as A. demani De Coninck & Schuurmans Stekhoven, 1933. Later, eleven species (A. schuurmansstekhoveni Allgén, 1935, A. odontophoroides Chitwood, 1936, A. subsimilis Chitwood, 1936, A. mediterraneus Brunetti, 1941, A. tirrenicus Brunetti, 1941, A. versiliensis Brunetti, 1941, A. longisetosus Allgén, 1947 a, A. tenuicollis Allgén, 1947 b, A. diegoensis Allgén, 1947 b, A. arcuatus Schuurmans Stekhoven, 1950 and A. leptosoma Allgén, 1951) have been described. Timm (1954) described A. filipjevi Timm, 1954 and A. steineri Timm, 1954, and redescribed A. demani and A. spinosus. Afterwards, A. tenuicaudatus Allgén, 1959, A. austrogeorgiae Allgén, 1959, A. drachi Luc & De Coninck, 1959, A. interrogativus Wieser, 1959 and A. stomamilivus Crites, 1961 were described. Hopper (1963) described A. paraponticus Hopper, 1963, provided a pictorial key to 21 species and considered A. austrogeorgiae, A. diegoensis, A. filiformis, A. leptosoma, A. limalis, A. longisetosus, A. tenuicollis as species inquirenda. After Hopper (1963), A. hexapilus Wieser & Hopper, 1967, A. orcombensis Warwick, 1970, A. seticaudatus Platonova, 1971, A. helgolandicus Lorenzen, 1971, A. caudostriatus Boucher, 1973, A. geminus Belogurov & Koroleva, 1975, A. orus Belogurov & Koroleva, 1975 and A. deconincki Vincx & Furstenberg, 1989 were described. More recently, Leduc & Zhao (2023) described A. glandifer Leduc & Zhao, 2023 and revised genus characters. There have been many transferences from the genus Axonolaimus mainly based on buccal cavity (Table 2). Axonolaimus versiliensis should be considered as species inquirenda for the description based on a juvenile specimen. Before the description in the present work 33 species were considered as valid.	en	Liang, Huixin, Guo, Wen, Wang, Chunming (2024): Two new species of Nematoda: Gairleanema pulchra sp. nov. (Tripyloididae) and Axonolaimus dimorphous sp. nov. (Axonolaimidae) from the Yellow Sea, China. Zootaxa 5447 (4): 547-561, DOI: 10.11646/zootaxa.5447.4.6, URL: http://dx.doi.org/10.11646/zootaxa.5360.3.8
F11C878FFB71FB38D985FDC438220CB9.taxon	description	(Figures 3 – 4, Table 3)	en	Liang, Huixin, Guo, Wen, Wang, Chunming (2024): Two new species of Nematoda: Gairleanema pulchra sp. nov. (Tripyloididae) and Axonolaimus dimorphous sp. nov. (Axonolaimidae) from the Yellow Sea, China. Zootaxa 5447 (4): 547-561, DOI: 10.11646/zootaxa.5447.4.6, URL: http://dx.doi.org/10.11646/zootaxa.5360.3.8
F11C878FFB71FB38D985FDC438220CB9.taxon	materials_examined	Type material. Four males and three females were measured and studied. Holotype: ♂ 1 on 22 LJW 3 – 2 – 4; paratypes: ♂ 2 on 22 LJW 3 – 1 – 11, ♂ 3 on 22 LJW 3 – 4 – 2, ♂ 4 on 22 LJW 3 – 4 – 2, ♀ 1 on 22 LJW 3 – 1 – 12, ♀ 2 on 22 LJW 3 – 4 – 4 and ♀ 3 on 22 LJW 3 – 3 – 16. Type locality and habitat. Specimens were collected from intertidal muddy sediment at Rizhao coast, Shandong Province, China, 35 ° 18 ′ N, 119 ° 31 ′ E; 0 – 2 cm sediment depth.	en	Liang, Huixin, Guo, Wen, Wang, Chunming (2024): Two new species of Nematoda: Gairleanema pulchra sp. nov. (Tripyloididae) and Axonolaimus dimorphous sp. nov. (Axonolaimidae) from the Yellow Sea, China. Zootaxa 5447 (4): 547-561, DOI: 10.11646/zootaxa.5447.4.6, URL: http://dx.doi.org/10.11646/zootaxa.5360.3.8
F11C878FFB71FB38D985FDC438220CB9.taxon	etymology	Etymology. Species epithet dimorphous refers to amphidial fovea different in male and female.	en	Liang, Huixin, Guo, Wen, Wang, Chunming (2024): Two new species of Nematoda: Gairleanema pulchra sp. nov. (Tripyloididae) and Axonolaimus dimorphous sp. nov. (Axonolaimidae) from the Yellow Sea, China. Zootaxa 5447 (4): 547-561, DOI: 10.11646/zootaxa.5447.4.6, URL: http://dx.doi.org/10.11646/zootaxa.5360.3.8
F11C878FFB71FB38D985FDC438220CB9.taxon	description	Descriptions Males. Body cylindrical, tapering slightly towards both extremities. Cuticle finely striated. Two lateral dorsal and two latero-ventral rows of somatic setae present along entire body, 5 – 7 µm in length. Anterior body end blunt and slightly rounded, lips short. Inner and outer labial sensilla papilliform, four cephalic setae, 1.2 – 1.4 c. b. d. (corresponding body diameter) in length. Four cervical setae, 7 – 8 µm in length, situated slightly posterior to amphids. Amphidial fovea elongated loop-shaped, situated slightly posterior to cephalic setae and slightly longer than buccal cavity. Buccal cavity funnel-shaped, with cuticularized walls, 16 – 18 µm in depth, 6 µm in width, without odontia. Pharynx cylindrical with posterior portion slightly widened. Nerve ring located at about two-thirds of pharynx length from anterior end. Secretory-excretory gland situated 40 µm posterior to pharynx end, secretory-excretory pore 34 µm from anterior end. Cardia short, triangular shaped. Reproductive system didelphic, with two opposed outstretched testes. Anterior testis to the left of intestine, posterior testis to the right of intestine. Spicules strongly cuticularized and arcuated, 1.2 cloacal body diameters along arc. Gubernaculum parallel to the distal end of spicules, with dorsal apophysis slightly directed to caudal position. Precloacal supplements absent. Tail conico-cylindrical with two rows of subventral setae and sparse subdorsal setae. Three caudal glands present. Females. Similar to males in most characteristics. Amphidial fovea loop-shaped. Reproductive system with two opposed outstretched ovaries, anterior ovary to the left of intestine and posterior ovary to the right of intestine. Spermatheca not observed. Vulva located slightly posterior to mid-body.	en	Liang, Huixin, Guo, Wen, Wang, Chunming (2024): Two new species of Nematoda: Gairleanema pulchra sp. nov. (Tripyloididae) and Axonolaimus dimorphous sp. nov. (Axonolaimidae) from the Yellow Sea, China. Zootaxa 5447 (4): 547-561, DOI: 10.11646/zootaxa.5447.4.6, URL: http://dx.doi.org/10.11646/zootaxa.5360.3.8
F11C878FFB71FB38D985FDC438220CB9.taxon	diagnosis	Differential diagnosis and discussion Axonolaimus dimorphous sp. nov. is characterized by four long cephalic setae, amphidial fovea elongated loop-shaped in males and loop-shaped in females, amphidial fovea at level of subcephalic setae, spicules arcuated, gubernaculum with dorsal apophysis slightly directed to caudal position and tail conico-cylindrical with caudal setae. Axonolaimus dimorphous sp. nov. differs from the other species in presenting amphidial fovea elongated loop-shaped in males and loop-shaped in females. It is similar to A. demani, A. filipjevi, A. helgolandicus, A. hexapilus, A. orcombensis, A. tenuis and A. typicus in the amphidial fovea shape in females, but it differs from A. demani in the body length (1452 – 1751 μm vs. 800 – 1187 μm), cephalic setae length (14 – 16 μm vs. 3 – 5 μm), spicules length (27 – 29 μm vs. 18 μm), gubernaculum apophysis length (8 – 9 μm vs. 13 μm), and tail length (7.3 – 8.3 anal body diameter vs. 5 – 6.5 anal body diameter) (Gerlach 1957); differs from A. filipjevi in the cephalic setae length (1.2 – 1.5 head diameter vs. 0.9 head diameter), presence of cervical setae (absent in A. filipjevi), spicules length (1.2 anal body diameter vs. 1 anal body diameter), gubernaculum apophysis shape (dorsal, slightly directed to caudal position vs. dorsal-caudal directed) (calculated based on Timm 1954); differs from A. helgolandicus in spicules length (27 – 29 μm vs. 42 μm), gubernaculum apophysis shape and length (dorsal slightly directed to caudal position, 8 – 9 μm vs. dorsal-caudal directed, 24 μm in length), precloacal supplements absent (16 tiny preanal papillae in A. helgolandicus) (calculated based on Lorenzen 1971); differs from A. hexapilus in the cephalic setae length (14 – 16 μm vs. 21 – 24 μm), spicules length (27 – 29 μm vs. 39 μm), precloacal supplements absent (present in A. hexapilus), and tail shape (conico-cylindrical vs. obtuse conoid); differs from A. orcombensis in the body length (1452 – 1752 μm vs. 2980 – 3620 μm), cephalic setae length (14 – 16 μm vs. 23 – 27 μm), cervical setae (four cervical setae vs. eight long cervical setae), spicules length (27 – 29 μm vs. 43 – 48 μm), precloacal supplements absent (20 – 30 precloacal supplements in A. orcombensis); differs from A. tenuis in the body length (1452 – 1752 μm vs. 3400 – 3800 μm), cephalic setae length (1.2 – 1.5 head diameter vs. 3 head diameter), spicules shape (arcuated vs. distal end with a hook), tail shape (tail conico-cylindrical vs. tail blunt); differs from A. typicus in the cephalic setae length (1.2 – 1.5 head diameter vs. 0.3 head diameter), presence of cervical setae (absent in A. typicus), gubernaculum apophysis shape (dorsal slightly directed to caudal position vs. caudal directed). Thus, 34 species should be considered valid and an identification key to valid species of the genus Axonolaimus is provided below.	en	Liang, Huixin, Guo, Wen, Wang, Chunming (2024): Two new species of Nematoda: Gairleanema pulchra sp. nov. (Tripyloididae) and Axonolaimus dimorphous sp. nov. (Axonolaimidae) from the Yellow Sea, China. Zootaxa 5447 (4): 547-561, DOI: 10.11646/zootaxa.5447.4.6, URL: http://dx.doi.org/10.11646/zootaxa.5360.3.8
