taxonID	type	description	language	source
03A93F65FFBBC60DFC9FF959FB91F8D4.taxon	description	Family Cyatholaimidae Filipjev, 1918	en	Lee, Hyo Jin, Jung, Jongwoo, Rho, Hyun Soo (2016): Two unrecorded marine nematode species of Paracanthonchus (Nematoda: Cyatholaimidae) from the East Sea of Korea. Journal of Species Research 5 (3): 503-513, DOI: 10.12651/JSR.2016.5.3.503, URL: http://dx.doi.org/10.12651/jsr.2016.5.3.503
03A93F65FFBBC608FCF0F897FC87F92E.taxon	description	A B C D three postcloacal setae present .................................... .................................... P. macrodon (Ditlevsen, 1918) - Gubernaculum rib­like structure with numerous cusps, without postcloacal setae ............ P. kamui Kito, 1981	en	Lee, Hyo Jin, Jung, Jongwoo, Rho, Hyun Soo (2016): Two unrecorded marine nematode species of Paracanthonchus (Nematoda: Cyatholaimidae) from the East Sea of Korea. Journal of Species Research 5 (3): 503-513, DOI: 10.12651/JSR.2016.5.3.503, URL: http://dx.doi.org/10.12651/jsr.2016.5.3.503
03A93F65FFBEC604FF0EF932FBDDF927.taxon	materials_examined	Material examined. 5 ♂♂ and 3 $$, Bugu­ri, Uljingun, Gyeongsangbuk­do, Korea (37 ° 06 ′ 21.39 ″ N, 129 ° 22 ′ 37.42 ″ E), collected on 9 July 2014 by Hyo Jin Lee; Jugwang­myeon, Goseong­gun, Gangwon­do, Korea (38 ° 19 ′ 41.65 ″ N, 128 ° 31 ′ 45.63 ″ E), collected on 2 Oct. 2014. The specimens are kept in the collection of the author. All are mounted in anhydrous glycerin between two coverslips on H­S slides, sealed with nail polish.	en	Lee, Hyo Jin, Jung, Jongwoo, Rho, Hyun Soo (2016): Two unrecorded marine nematode species of Paracanthonchus (Nematoda: Cyatholaimidae) from the East Sea of Korea. Journal of Species Research 5 (3): 503-513, DOI: 10.12651/JSR.2016.5.3.503, URL: http://dx.doi.org/10.12651/jsr.2016.5.3.503
03A93F65FFBEC604FF0EF932FBDDF927.taxon	description	Measurements. See Table 1 for detailed measurements and morphometric ratios. Description. Males: Body length 2,282 ­ 2,557 μm long, cylindrical, slightly tapering anterior (Figs. 1 A, 3 A). Maximum body diameter 87 ­ 104 μm. Cuticle marked homogeneously, closely arranged in transverse rows of fine punctations, starting at level of cephalic setae. Space of rows relatively narrow at mid­body region, slightly larg­ er and broader at extremities. Cuticle pore about 2 μm wide, distributed throughout body (Figs. 1 C, 3 D). Between amphideal fovea and never ring region arranged at about six rows within 10 μm; in middle of body about seven to eight rows within same distance. Lateral modified punctuations appeared throughout body, but more distinct and numerous in pharyngeal and tail region. Head with inner circle of six labial papillae about 3 μm long and outer circle of 10 (6 + 4) cephalic setae, four shorter cephalic setae 8.7 ­ 10.8 μm and six longer setae 12.3 ­ 16.1 μm, 34 - 44 % of head diameter. Buccal cavity with prominent large dorsal tooth and two minute subventral teeth (Figs. 1 C, 3 B). Amphideal fovea ventrally wound spiral with 3.75 turns, about 32 ­ 35 % of head diameter. Amphideal fovea height equal to eight to ten punctuation rows (Figs. 1 C, 3 C). Ocelli absent. Esophagus cylindrical, 359 ­ 403 μm long, slightly broadened at its base. No distinct cardia. Nerve ring encircling pharynx, situated at 46 ­ 51 % of pharynx length from anterior end. Excretory pore opening located at 100.2 ­ 119.8 μm from anterior end, small ventral gland located in esophagus end (Fig. 1 B). Cervical setae 6.7 ­ 9.5 μm long, and a few somatic setae sparsely distributed throughout body along subdorsal and subventral. Tail rather plumped, conical, with swollen tip, 178 ­ 205 μm long, about 2.4 - 2.6 times of anal body diameter. Three long and stout post­cloacal setae present, anterior two setae longer than backmost setae. Cell bodies of three caudal glands situated in proximal third, subventral and subdorsal setae situated at tail region (Figs. 1 F, 3 H). Reproduction system diorchic. Spicules paired, arcuate, slightly bent at middle part and tapering distally. Gubernaculum paired, slightly shorter than spicules. Proximal portion rather sharp, and distal one­third broadening with massively enlarged distally L­shaped, distal end plate about 16 ­ 20 μm wide, with numerous cusps, and three or four large cusps (Figs. 1 E, 1 F, 3 E, 3 G). Six precloacal supplestretched. Vulva 1,026 ­ 1,179 μm from anterior end, situated at 46 ­ 48 % of total body length (Fig. 2 E). Tail short anal body diameter (Fig. 2 C).	en	Lee, Hyo Jin, Jung, Jongwoo, Rho, Hyun Soo (2016): Two unrecorded marine nematode species of Paracanthonchus (Nematoda: Cyatholaimidae) from the East Sea of Korea. Journal of Species Research 5 (3): 503-513, DOI: 10.12651/JSR.2016.5.3.503, URL: http://dx.doi.org/10.12651/jsr.2016.5.3.503
03A93F65FFBEC604FF0EF932FBDDF927.taxon	discussion	Remark. In 1918, Ditlevsen reported the species Cyatholaimus macrodon Ditlevsen, 1918 from Oresund in Danish belt Sea. Thereafter, Micoletzky erected the genus Paracanthonchus with 5 species including P a r a c a n t h o n c h u s m a c ro d o n (D i t l e v s e n, 1 9 1 8). Paracanthonchus macrodon has been previously report­ ed from Europe, America and Japan Sea. The present Korean specimens were discovered from the seagrass bed of intertidal rocky shore of the East Sea, Korea. Paracanthonchus macrodon is distinguished from its congeners in having the cuticular differentiation, strongly dilated gubernaculum with numerous cusps, presence of three post­cloacal setae, and arrangement of six (4 + 2) precloacal supplement. The present specimens resemble P. hartogi Inglis, 1970, P. parahartogi Decraemer and Coomans, 1978, P. stekohveni Wieser, 1954 and P. sunesoni (Allgen, 1942), mainly in possessing six precloacal supplements and a more or less pronounced L­shaped gubernaculum with a large, spiny distal part in lateral view. Paracanthonchus macrodon is clearly distinguished from P. stekhoveni and P. sunesoni by arrangement of precloacal suppelements. Distance of among the four precloacal supplements is almost equal in P. stekhoveni and P. sunesoni, but distance of anteriormost and second supplement is longer than other adjacent supplements in P. macrodon. Paracanthonchus hartogi has a fine striation cuticle without lateral differentiation, whereas P. macrodon has fine punctuations and lateral differentiation. Moreover, P. macrodon has long and stout three postcloacal setae, but P. parahartogi dosen’t have postcloacal setae. The present Korean specimens are very similar with the original description by Ditlevsen 1918, except for position of the excretory pore (100.2 ­ 119.8 μm vs. 18 μm from anterior end), turns of amphideal fovea (3.75 vs. 2.5 turns) and number of precloacal supplements (six vs. four). The Korean specimens are closely related to P. macrodon reported from subtidal zone in the coasts of Oshoro, Japan by Kito (1978) in general features. However, Korean specimens are not accorded by distance of among anterior four precloacal supplements (50 μm, 26 μm, 25 μm vs. 35 μm, 11 μm, 24 μm respectively).	en	Lee, Hyo Jin, Jung, Jongwoo, Rho, Hyun Soo (2016): Two unrecorded marine nematode species of Paracanthonchus (Nematoda: Cyatholaimidae) from the East Sea of Korea. Journal of Species Research 5 (3): 503-513, DOI: 10.12651/JSR.2016.5.3.503, URL: http://dx.doi.org/10.12651/jsr.2016.5.3.503
03A93F65FFB2C605FCE7F8CAFCD8FA9D.taxon	materials_examined	Material examined. 5 ♂♂ and 3 $$, Bugu­ri, Uljingun, Gyeongsangbuk­do, Korea (37 ° 06 ′ 21.39 ″ N, 129 ° 22 ′ 37.42 ″ E), collected on 9 July 2014; Jangsa­dong, Sokcho­si, Gangwon­do, Korea (38 ° 13 ′ 37.77 ″ N, 128 ° 35 ′ 16.92 ″ E); Janghohang­gil, Geundeok­myeon, Samcheok­si, Gangwon­do, Korea (37 ° 17 ′ 21.24 ″ N, 129 ° 19 ′ 8.34 ″ E); Ayajin­gil, Toseong­myeon, Goseong­gun, Gangwon­do, Korea (38 ° 16 ′ 11.53 ″ N, 128 ° 33 ′ 27.23 ″ E), collected on 2 Oct. 2014. The specimens are kept in the collection of the author. All are mounted in anhydrous glycerin between two coverslips on H­S slides, sealed with nail polish.	en	Lee, Hyo Jin, Jung, Jongwoo, Rho, Hyun Soo (2016): Two unrecorded marine nematode species of Paracanthonchus (Nematoda: Cyatholaimidae) from the East Sea of Korea. Journal of Species Research 5 (3): 503-513, DOI: 10.12651/JSR.2016.5.3.503, URL: http://dx.doi.org/10.12651/jsr.2016.5.3.503
03A93F65FFB2C605FCE7F8CAFCD8FA9D.taxon	description	Measurements. See Table 2 for detailed measurements and morphometric ratios. Description. Males: Body length 1,774 ­ 1,991 μm long, comparatively stout and cylindrical, slightly tapers to anterior region (Figs. 4 A, 6 A). Maximum body diameter 62 ­ 82 μm. Cuticle marked with transverse rows of fairly distinct dots starting at level of cephalic setae, but slightly lager and irregular in tail region. In pharyngeal region, distance of rows about 1.7 μm, slightly wide. Cuticle pore about 2 μm wide, distributed throughout body. About six to seven rows arranged in 10 μm at posterior part of body region, and about eight to ten rows situated at middle of body region within same distance (Figs. 4 C, 6 D). Head with inner circle of six labial papillae about 3.5 μm long and outer circle of 10 (6 + 4) cephalic setae, four shorter cephalic setae 7.8 ­ 9.8 μm and six longer setae 12.1 ­ 13.7 μm, about 41 - 46 % of head diameter. Buccal cavity with prominent large dorsal tooth and two small subventral teeth (Figs. 4 C, 6 B). Amphideal fovea with 4.25 turns in ventral direction, about 39 ­ 41 % of head diameter (Figs. 4 C, 6 C). Ocelli 4.8 ­ 7.0 μm long, situated at lower side of amphideal fovea. Esophagus cylindrical, 343 ­ 358 μm long, no distinct cardia. Nerve ring encircling pharynx, situated at 42 ­ 46 % of pharynx length from anterior end. Excretory pore opening located at 73.5 ­ 84.8 μm from anterior end (Fig. 4 B). Tail fairly stout, conical, 136 ­ 165 μm long, about 2.4 - 2.8 times of anal body diameter. Cell bodies of three caudal glands situated in proximal third, 4 ­ 5 μm setae distributed throughout tail region (Fig. 4 D). Spicules slender, arcuate and tapering distally; proximal end with swellon appearance and rapidly narrowing from middle part to distal end. Gubernaculum paired, slightly bent; proximal end with hook­shaped appearance, distally from one­third widening with shape of ribs, distal end expanded, with small and numerous cusps (Figs. 4 F, 6 F). Six precloacal supplements present; curved tubular shape; posteriormost supplement rather delicate. Distance between adjacent two supplements, relatively constant, but posterior two supplement very close together (Figs. 4 E, 6 E). A series of short setae distributed on both lateral side of subventral region. Females: General morphology similar to that of males in structure of cuticle and anterior body end (Fig. 5 B, 5 D). Body length 1,851 ­ 2,044 μm long; maximum body diameter 72 ­ 85 μm (Fig. 5 A). Reproductive system didelphic, ovaries paired opposed, reflexed. Vulva 907 ­ 974 μm from anterior end, situated at 48 - 49 % of total body length (Fig. 5 E). Tail short and conoid, 148 ­ 158 μm long, about 2.8 - 3.0 times of anal body diameter (Fig. 5 C).	en	Lee, Hyo Jin, Jung, Jongwoo, Rho, Hyun Soo (2016): Two unrecorded marine nematode species of Paracanthonchus (Nematoda: Cyatholaimidae) from the East Sea of Korea. Journal of Species Research 5 (3): 503-513, DOI: 10.12651/JSR.2016.5.3.503, URL: http://dx.doi.org/10.12651/jsr.2016.5.3.503
03A93F65FFB2C605FCE7F8CAFCD8FA9D.taxon	discussion	Remark. Paracanthonchus kamui Kito, 1981 was firstly described from Japan Sea coast in Hokkaido. Paracanthonchus kamui is distinguished from other species of the genus by having the 4.25 turns amphideal fovea, six tubular supplement, rib­shaped gubernaculums with proximally hook­shaped and distally broaden. The present species is most like P. austrospectabilis Wieser, 1954 and P. sonadiae Timm, 1961 by possessing gubernaculum with slightly dilated distal end, six precloacal supplements, buccal cavity with large dorsal tooth and two small subventral teeth. However, the present Korean species is significantly differs from P. austrospectabilis by the distance of among six precloacal supplements and the presence of tiny denticles of the distal plates of gubernaculums. The present species clearly distinguished from P. sonadiae by shorter tail length (2.7 ­ 3.0 abd vs. 3.1 ­ 4.0 abd) and turns of the amphideal fovea (4.25 turns vs. 5.5 turns). The present Korean specimens agree well with Kito’s (1981) original description, in general features, especially in the detailed structure of the gubernaculum, in the number and shape of the precloacal supplement, and in the features of the buccal armatures and the amphideal fovea. However, the Korean specimens of P. kamui are not accord with the original description by having a longer overall body length (1774 ­ 1991 μm in male, 1851 ­ 2044 μm in female vs. 1658 - 1728 μm, 1761 - 1816 μm) and ocelli situated at 24 - 28 μm from anterior end.	en	Lee, Hyo Jin, Jung, Jongwoo, Rho, Hyun Soo (2016): Two unrecorded marine nematode species of Paracanthonchus (Nematoda: Cyatholaimidae) from the East Sea of Korea. Journal of Species Research 5 (3): 503-513, DOI: 10.12651/JSR.2016.5.3.503, URL: http://dx.doi.org/10.12651/jsr.2016.5.3.503
