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Vakati, Vinod, Lee, Wonchoel (2021): -On- two- new- species- of- Nannopus- Brady,- 1880- (Copepoda:- Harpacticoida Nannopodidae)-from-intertidal-mudflats-of-the-Korean-west-coast-(Yellow-Sea). Zootaxa 5051 (1): 529-549, DOI: https://doi.org/10.11646/zootaxa.5051.1.21

Nannopus robustus ­sp.­nov. (Figs. 4–5) Type­ locality. Intertidal mudflat, St-8— Yeongheung-myeon, Ongjin-gun, Korea, Yellow Sea, 37°14’16.6”N 126°28’16.8”E (Fig. 1). Type­ material. Holotype: 1 male adult in 70% ethanol (NIBRIV0000860821). Samples were collected by Vinod Vakati, 20 November 2013. Etymology. The species epithet is derived from the Latin “robustus”, referring to the very strong and sturdy distal-most apical spine of P2 exp-2. Description­ of­ male­(based­ on­ holotype).­ Body fusiform (Fig. 4A–B) narrow, total body length 461 μm, measured from tip of rostrum to posterior margin of caudal rami. Maximum width 138 μm, measured at posterior margin of cephalothorax. Body slightly slender, tapering posteriorly. Urosome/prosome length ratio 0.71 (Fig. 4A) and body length/width ratio about 3.3. Body ornamentation as in N. serratus (see Vakati & Lee 2017: 24, 27, Figs. 17A–F, 19A–D). Each urosomite with rows of slim setules ventrally as in N. serratus (see Vakati & Lee 2017: 24, Fig. 17F). Cephalothorax (Fig. 4A) bell-shaped, slightly narrow, comprising 36% of total body length, with a few paired sensilla and serrated posterior margin. Rostrum as in N. serratus (see Vakati & Lee 2017: 23, Fig. 16C). Prosome (Fig. 4A–B) 4-segmented, comprising cephalothorax and three subequal free pedigerous somites. P2-bearing somite with two long medial sensilla dorsally, posterior margins of prosomites serrated, and with few sensilla as figured. Urosome (Fig. 4A–B) 5-segmented, comprising P5-bearing somite, genital double-somite, two free abdominal somites, and anal somite. Posterior margins of urosomites serrated dorsally and ventrally. Posterior margin of genital double-somite and following somite with pair of strong sensilla ventrally as in N. serratus (see Vakati & Lee 2017: 29, arrowed in Fig. 21B). Each somite with one transverse row of spinules along posterior margin ventrally. Genital double-somite as in N. serratus (see Vakati & Lee 2017: 29, Fig. 21B), clearly distinct dorsally and ventrally, with serrated dorsal posterior margin. Anal somite (Figs. 4A, 5A–C) almost as long as wide with unique pattern of surface ornamentation dorsally as in N. serratus, ventral surface with six spinules (see Vakati & Lee 2017: 29, Fig. 21C–D). Caudal rami (Fig. 5A–C) square (dorsally) or sub-cylindrical (ventrally), almost as long as wide (in dorsal view), almost twice as long as wide (in ventral view), and with row of spinules along posteroventral margins. Caudal ramus bearing seven setae: seta I pinnate, shorter than ramus width, and located anterolaterally; seta II pinnate, almost as long as ramus length, and inserted anterolaterally midway along outer margin; seta III pinnate, as long as ramus length, and inserted anterolaterally midway along outer margin; seta IV bipinnate, 0.5 times as long as seta V, located at outer posterior margin and wide at proximal region; seta V strongest, bipinnate with proximal part heavily cylindrical and smooth (arrowed in Fig. 5A–C), and located at inner posterior margin; seta VI naked, small, and located at inner posterior corner; seta VII slender, flexible, triarticulate, pinnate, located midway along inner margin. Antennule, maxillule, maxilla, and maxilliped as in N. ganghwaensis (see Vakati et al. 2016: 218, Fig. 4A, D–F). Antenna, mandible, P1– P6 as in N. serratus (see Vakati & Lee 2017: 23, 25, 30, Figs. 16D–F, 18A, E, 22 B–D). P2 (Fig. 5D–E) with smooth and short concave intercoxal sclerite (not illustrated). Praecoxa somewhat triangular and shorter than coxa. Coxa with one spinular row on anterior surface. Basis with one row of outer spinules on anterior surface, one row of distal spinules near insertion of exopod, and one row of distal spinules near insertion of endopod. Basal outer seta naked. Exopod 3-segmented, and all segments subequal in length. Each exopodal segment with robust outer spinules and without inner setules. Exp-2 without inner seta. Exp-1 to -2 with serrated outer spines, exp-3 outer spines smooth, and outer distal-most spine heavily robust (arrowed in Fig. 5D), hook-shaped or recurved, and relatively longer. Endopod 2-segmented, both segments subequal in size, with one smooth outer distal spine and one pinnate inner distal seta. Female. Unknown., Published as part of Vakati, Vinod & Lee, Wonchoel, 2021, - On- two- new- species- of- Nannopus- Brady, - 1880 - (Copepoda: - Harpacticoida Nannopodidae) - from-intertidal-mudflats-of-the-Korean-west-coast- (Yellow-Sea), pp. 529-549 in Zootaxa 5051 (1) on pages 531-537, DOI: 10.11646/zootaxa.5051.1.21, http://zenodo.org/record/5563966, {"references":["Vakati, V., Eyun, S. & Lee, W. (2019) Unraveling the intricate biodiversity of the benthic harpacticoid genus Nannopus (Copepoda, Harpacticoida, Nannopodidae) in Korean waters. Molecular Phylogenetics and Evolution, 130, 366 - 379. https: // doi. org / 10.1016 / j. ympev. 2018.10.004","Kim, J. G., Choi, H. K. & Yoon, S. M. (2017) A reappraisal of the genera Nannopus Brady, 1880 and Ilyophilus Lilljeborg, 1902 (Copepoda, Harpacticoida, Nannopodidae) with a description of N. parvipilis sp. nov. from South Korea. Crustaceana, 90, 1351 - 1365. https: // doi. org / 10.1163 / 15685403 - 00003700","Vakati, V. & Lee, W. (2017) Five new species of the genus Nannopus (Copepoda: Harpacticoida: Nannopodidae) from intertidal mudflats of the Korean West Coast (Yellow Sea). Zootaxa, 4360 (1), 1 - 66. https: // doi. org / 10.11646 / zootaxa. 4360.1.1","Vakati, V., Kihara, T. C. & Lee, W. (2016) A new species of the genus Nannopus (Copepoda, Harpacticoida, Nannopodidae) from the mudflat of Ganghwa Island, Korea. Proceedings of the biological Society of Washington, 129, 212 - 233. https: // doi. org / 10.2988 / 0006 - 324 X- 129. Q 3.212"]}

Nannopus cylindricus ­sp.­nov.­ (Figs. 2–3) Type­ locality. Intertidal mudflat, St-6a— Gilsang-myeon, Ganghwa Island, Korea, Yellow Sea, 37°35’55.9”N 126°30’49.2”E (Fig. 1). Type­material. Holotype: 1 female adult in 70% ethanol (NIBRIV0000860820). Samples were collected by Vinod Vakati, 06 March 2015. Etymology. The species epithet is derived from the Latin “cylindricus”, cylindrical, and alludes to the shape of the proximal region of caudal seta V. Description­of­female­(based­on­holotype). Body (Fig. 2A–B) fusiform narrow, total body length 719 μm, measured from tip of rostrum to posterior margin of caudal rami. Maximum width 218 μm, measured at posterior margin of cephalothorax. Boundary between prosome and urosome clearly visible, urosome/prosome length ratio 0.73, and body length/width ratio about 3.2. Body ornamentation consisting of dorsal denticles, and horizontal row of setules as in N. ganghwaensis (see Vakati et al. 2016: 217, Fig. 3A–D). Cephalothorax (Fig. 2A) anteriorly attenuated in dorsal view, comprising 28% of total body length, posterior margin serrated, with several paired sensilla and one row of sensilla (Fig. 2A). Rostrum as in N. ganghwaensis and with pair of sensilla as in N. didelphis (see Fiers & Kotwicki 2013: 41, Fig. 4G; Vakati et al. 2016: 216, Fig. 2C). Prosome (Fig. 2A) 4-segmented, comprising cephalothorax and three subequal pedigerous somites. P1-bearing somite fused to cephalothorax, posterior margin of free pedigerous somites serrated, and with row of sensilla posteriorly. Urosome (Fig. 2A–B) tapering posteriorly, comprising P5-bearing somite, genital double-somite, two free abdominal somites, and anal somite. Posterior margin of P5-bearing somite and first half of genital double-somite serrated dorsally; second half of genital double-somite, fourth and fifth urosomites with posterior margin serrated dorsally and ventrally; each somite with sensilla dorsally except for penultimate somite and one row of spinules ventrally. Genital double-somite as in N. ganghwaensis (see Vakati et al. 2016: 221, Fig. 7A), completely fused ventrally, distinct dorsally and laterally (Fig. 2A–B), with serrated posterior margin dorsally, and smooth ventrally except for spinular row along posterior margin; copulatory pore not visible (completely translucent). Anal somite (Figs. 2A, 3A–B) with well-developed operculum, covered with setules posteriorly; almost as long as wide, with pair of dorsal sensilla and with one row of spinules on either side of somite ventrally. Caudal rami (Fig. 3A–C) cylindrical, clearly separated from anal somite, 1.7 (in dorsal view) and 2 (in ventral view) times as long as wide. Ornamentation consisting of setules as in N. ganghwaensis (see Vakati et al. 2016: 222, Fig. 8A–B), and row of spinules along posterior margin ventrally (Fig. 3B). Caudal ramus bearing seven setae: seta I naked, shorter than ramus width, located anterodorsally; seta II naked, shorter than ramus width, inserted anterodorsally midway and close to outer margin; seta III naked, almost as long as ramus length, and inserted anterolaterally midway along outer margin; seta IV bipinnate, located distally, and 0.5 times as long as seta V; seta V longest, bipinnate, located distally, anterior part inflated and heavily cylindrical (arrowed in Fig. 3A–C); seta VI small, and naked; seta VII triarticulate, naked, and located midway along inner margin. Antennule, antenna, mouth parts, P1– P6 as in N. ganghwaensis (see Vakati et al. 2016: 218–221, Figs. 4A–F, 5A–B, 6A–B, 7A–D, E). Male. Unknown., Published as part of Vakati, Vinod & Lee, Wonchoel, 2021, - On- two- new- species- of- Nannopus- Brady, - 1880 - (Copepoda: - Harpacticoida Nannopodidae) - from-intertidal-mudflats-of-the-Korean-west-coast- (Yellow-Sea), pp. 529-549 in Zootaxa 5051 (1) on page 531, DOI: 10.11646/zootaxa.5051.1.21, http://zenodo.org/record/5563966, {"references":["Vakati, V., Kihara, T. C. & Lee, W. (2016) A new species of the genus Nannopus (Copepoda, Harpacticoida, Nannopodidae) from the mudflat of Ganghwa Island, Korea. Proceedings of the biological Society of Washington, 129, 212 - 233. https: // doi. org / 10.2988 / 0006 - 324 X- 129. Q 3.212","Fiers, F. & Kotwicki, L. (2013) The multiple faces of Nannopus palustris auct. reconsidered: A morphological approach (Copepoda: Harpacticoida: Nannopodidae). Zoologischer Anzeiger, 253, 6 - 65. https: // doi. org / 10.1016 / j. jcz. 2013.08.001"]}

Nannopus minutus sp. nov. (Figs. 2–8) Type locality. Intertidal mudflat, Gilsang-myeon, Ganghwa Island, South Korea, Yellow Sea, 37°35'55.9"N 126°30'49.2"E (Fig. 1A, B). Type material. Holotype: 1 female adult in 70% ethanol (NIBRIV0000753983). Allotype: 1 male adult in 70% ethanol (NIBRIV0000810831). Paratypes: 2 females dissected on 4 and 3 slides (NIBRIV0000810828 – 29),1 male dissected on 5 slides (NIBRIV0000810832); 2 females on an SEM stub (NIBRIV0000810830). All samples were collected by Vinod Vakati, 20 November 2013. Etymology. The species epithet is derived from the Latin “ minutus ”, small, and alludes to the small size of the species (both sexes). Description of female (based on holotype and paratypes). Body (Fig. 2A, B) fusiform narrow, total body length ranged from 498 to 504 µm (mean = 500 µm, n = 3; holotype: 504 µm, measured from tip of rostrum to posterior margin of caudal rami). Maximum width ranged from 140 to 151 µm (mean 146 µm, n = 3; holotype: 140 µm, measured at posterior margin of cephalothorax). Boundary between prosome and urosome clearly visible, urosome/prosome length ratio 0.65, and body length/width ratio about 3.3. Body ornamentation (Fig. 6A–D) consisting of dorsal denticles, and horizontal row of setules. Cephalothorax (Figs. 2A, B, 6C) anteriorly attenuated in dorsal view, almost as long as wide, comprising 29% of total body length, posterior margin serrated, with few paired sensilla, 1 row of sensilla, and 3 integumental windows (1 large medial posterior and 1 pair of small dorsolateral windows, arrowed in Fig. 6C). Rostrum (Fig. 2C) prominent (not visible from dorsal view), deeply recurved downwards, fused to cephalothorax, anterior margin densely hirsute, and with pair of sensilla (not figured). Prosome (Fig. 2A) 4-segmented, comprising cephalothorax and 3 subequal pedigerous somites. P1-bearing somite fused to cephalothorax, posterior margin of free pedigerous somites serrated, and with row of sensilla posteriorly. Urosome (Figs. 2A, B, 5A, 6C) tapering posteriorly, comprising P5-bearing somite, genital double-somite, 2 free abdominal somites and anal somite. Posterior margin of P5-bearing somite and first half of genital doublesomite serrated dorsally, second half of genital double-somite, fourth and fifth urosomites with posterior margin serrated dorsally and ventrally, each somite with sensilla dorsally except for penultimate somite and 1 row of spinules ventrally. Genital double-somite (Figs. 2A, B, 5A, 6C) almost 1.7 times as wide as long (ventral view), completely fused ventrally, distinct dorsally and laterally, with serrated posterior margin dorsally, and smooth ventrally except for spinular row along posterior margin, and copulatory pore not visible (completely translucent). Anal somite (Figs. 5A–C, 6C, D) with well-developed operculum, covered with setules posteriorly, almost as long as wide, with pair of dorsal sensilla, and with 1 row of spinules on either side of somite ventrally. Caudal rami (Figs. 5A–C, 6A, B) cylindrical, with clear separation from anal somite, 1.3 (in dorsal view) and 2 (in ventral view) times as long as width. Ornamentation consisting of setules (Fig. 6A, B), and row of spinules along posterior margins dorsally and ventrally (Fig. 5A, C). Caudal ramus bearing 7 setae: seta I naked, shorter than ramus width, located anterodorsally; seta II naked, almost as long as ramus width, inserted anterodorsally midway and close to inner margin; seta III bipinnate, almost as long as ramus length, and inserted anterolaterally midway along outer margin; seta IV bipinnate, 0.2 times as long as seta V, inflated, leaf-shaped, located distally, and dorsal to seta V; seta V longest, bipinnate, anterior part wide and smooth, located distally, and ventral to seta IV; seta VI small, and naked; seta VII triarticulate, naked, and located midway along inner margin. Antennule (Fig. 3A) 5-segmented, first and second segments strongest and widest, third segment with aesthetasc fused basally to 1 naked seta, fourth segment smallest, short and compact, and fifth segment with apical acrothek consisting of 1 slender aesthetasc fused basally to 2 long naked setae. All segments smooth except for spinular row on first and third segments. Armature formula: [1], 2-[6 + 3 pinnate], 3-[6 + (1 + ae)], 4-[1], 5-[8 + acrothek]. Antenna (Fig. 3B) comprising allobasis and free 1-segmented endopod. Allobasis with 2 abexopodal pinnate setae. Free endopodal segment 1.8 times as long as wide, with long medial outer spinules, with some spinules on inner and outer distal corners, with 5 strong, rigid naked elements and 1 long naked (innermost element), relatively slender element. Exopod 1-segmented, small, as long as wide, and with 4 elements (1 sparsely bipinnate and 3 naked). Mandible (Fig. 3C) with well-developed gnathobasis, bearing several multicuspidate teeth distally, 1 small pinnate seta, and with 1 row of medial spinules near basis. Mandibular palp 1-segmented and incorporated into basis, armed with 4 bipinnate setae (1 basal, 2 exopodal and 1 endopodal), and 1 row of slender medial spinules. Maxillule (Fig. 3D) praecoxa with few outer spinules proximally. Praecoxal arthrite well developed with few spinules, 2 naked surface setae, 8 stout naked spines/setae, and 2 bipinnate lateral setae. Syncoxa with cylindrical coxal endite bearing 2 naked setae. Basis and rami fused, outer margin with few spinules, and with 8 setae [5 basal (3 naked, 1 pinnate, 1 unipinnate), 1 endopodal unipinnate, and 2 exopodal bipinnate setae]. Maxilla (Fig. 3E) with large syncoxa bearing 1 row of outer spinules proximally, 2 subequal endites, and each with 3 elements fused to segment (2 spinulose and 1 slender naked). Allobasis into long naked curved claw with 1 accompanying naked seta. Endopod incorporated into basis, and represented by 2 naked setae. Maxilliped (Fig. 3F) comprising syncoxa, basis, and 2-segmented endopod. Syncoxa shorter than basis, with 1 short distal naked seta. Basis almost 2 times as long as width with longitudinal row of medial spinules. Endopod 2- segmented, distal segment with 1 strong curved claw ornamented with rigid spinules in distal half, and 2 naked accessory setae at proximal region. P1–P4 (Fig. 4A–D) with smooth and short concave intercoxal sclerite (P2 and P3 illustrated). Praecoxa somewhat triangular and shorter than coxa, with 1 row of outer spinules. Coxa with 1 (P1, P2 and P3) or 2 (P4) spinular rows on anterior surface, and row of strong outer spinules (P2, P3 and P4). Basis with 1 row of strong outer spinules near insertion of exopod and 1 row of distal spinules near insertion of endopod. Basal outer seta naked (P1, P2 and P4) or bipinnate (P3), and inner spine (with few spinules) on P1. Exopod 3-segmented, and all segments subequal. Exp-1 to -3 with robust outer spinules. Exp-2 (P1) and exp-1 to -3 (P2, P3 and P4) with inner setules. Exp-2 (P1, P2, P3 and P4) with pinnate inner seta, and exp-3 (P1, P2, P3 and P4) with pinnate inner subdistal, distal and outer terminal setae. P4 exp-3 with 1 inner subdistal pectinate seta. Endopod 2-segmented in P1, P2 and P3 or 1-segmented in P4. Enp-1 to -2 (P1, P2 and P3) with robust outer spinules. Enp-1 to -2 (P1), enp- 2 (P2 and P3) with slender inner setules. All setae on P1–P4 endopods pinnate except for inner apical short seta on P4 endopod (Fig. 4D). Armature formula as follows: P5 (Fig. 5D) with separate baseoendopod and exopod. Baseoendopod transversely elongated, with inner spinules on endopodal lobe and close to exopod, with 2 pectinate and 2 pinnate setae. Exopod squarish, almost as long as wide, with 5 elements (innermost element longest, bipinnate, and fused to segment, medial 2 setae pinnate and outermost 2 setae naked). P6 (Fig. 5A, E) with 1 small flap bearing 1 small pinnate seta. Description of male (based on allotype and paratypes). Body (Fig. 7A) as in female except for total body length ranged from 428 to 434 µm (mean = 431 µm, n = 2; allotype: 428 µm, measured from tip of rostrum to posterior margin of caudal rami). Maximum width ranged from 118 to 123 µm (mean 120 µm, n = 2; allotype: 118 µm, measured at posterior margin of cephalothorax). Urosome/prosome ratio about 0.7, and body length/width ratio about 3.5. Cephalothorax (Fig. 7A) without integumental windows. Body ornamentation (not illustrated), rostrum (Fig.7A), antenna (not illustrated), mouth parts (not illustrated), P1 and P4 (not illustrated) as in female. Prosome 4-segmented (Fig. 7A), comprising cephalothorax (bearing first pedigerous somite), and 3 free somites. Posterior margin of prosomites serrated and with sensilla as in female. Urosome 6-segmented (Fig. 7A, B), comprising P5-bearing somite, genital somite and 3 free abdominal somites and anal somite. Posterior margin of urosomites serrated except for anal somite and with sensilla as in female, P6-bearing somite and urosomite 3 to 5 with longitudinal row of spinules close to posterior margin ventrally. Genital somite (Fig. 7A, B) homologous to anterior part of genital double-somite in female. P6-bearing somite and third urosomite well segmented ventrally, 3.3 times as wide as long in ventral view, and with 1 spermatophore located on right side extending from posterior part of P4-bearing somite to posterior part of genital somite. FIGURE 4. Nannopus minutus sp. nov., line drawings, A–B, paratype ♀ 1; C–D, paratype ♀ 2: A, P1; B, P2; C, P3; D, P4; E– F, P2 and P3 intercoxal sclerite. Anal somite (Fig. 7A) as in female except for anal operculum deeply protruded downwards. Caudal rami (Fig. 7A–D) as in female except for small inner projection (arrowed in Fig. 7B). Seta IV 0.4 times as long as seta V, but twice as long as one in female, seta V anterior part as in female, and posterior part more flexible than in female. Antennule (Fig. 8E) chirocer, 7-segmented, with strong geniculation between segments 5 and 7. Segment 1 with 1 row of spinules along inner margin. Segment 2 longer than segment 1. Segment 4 represented by 1 small sclerite located posteriorly, with 1 seta. Armature formula as follows: 1-[1], 2-[6 + 3 pinnate], 3-[3], 4-[1], 5-[6], 6- [9(1 + ae)], 7-[7 + acrothek]. Apical acrothek consisting of 1 minute aesthetasc and 2 naked setae. P2–P3 (Fig. 8A, B) almost as in female except for P3 praecoxa without spinular row. P2 coxa with only 1 spinular row along anterior surface. Exopod 3-segmented, P2 exp-1 with pinnate outer spine, and exp-2 inner seta extremely smaller than in female (arrowed in Fig. 8A). Endopod 2-segmented, P3 enp-2 inner seta extremely short and naked (arrowed in Fig. 8B), and outer spine fused to segment forming sharp and naked apophysis (arrowed in Fig. 8B). P5 (Fig. 8C) fused with somite, exopod and baseoendopod fused, and both baseoendopods confluent. Baseoendopod with distal spinules, and outer basal bipinnate seta. Endopodal lobe with 2 sub-equal pectinate and 2 bipinnate setae. Exopodal lobe with 5 elements (3 bipinnate and 2 naked, and outer naked seta smallest). P6 (Figs. 7B, 8D) asymmetrical, only right flap functional, and with row of spinules distally. Each P6 with 3 bipinnate setae, medial element longest, and each seta arising from cylindrical peduncle.

Nannopus dimorphicus sp.nov. (Figs. 9���15) Type locality. Intertidal mudflat, Seocheon-gun, Chungcheongnam-do, South Korea, Yellow Sea, 36��01'45.2"N 126��39'56.0"E (Fig. 1A, C). Type material. Holotype: 1 female adult in 70% ethanol (NIBRIV0000753984). Allotype: 1 male adult in 70% ethanol (NIBRIV0000810836). Paratypes: 2 females dissected on 5 and 2 slides (NIBRIV0000810833 ��� 34) 1 male dissected on 4 slides (NIBRIV0000810837); 2 females and 2 males on SEM stub (NIBRIV0000810835). All samples were collected by Vinod Vakati, 27 May 2015. Etymology. The species epithet is derived from the Greek ��� dimorphicus ��� referring to the sexual dimorphism in shape of caudal seta V. Description of female (based on holotype and paratypes). Body (Fig. 9A, B) fusiform and broad along posterior region of cephalothorax, total body length ranged from 400 to 420 ��m (mean = 408 ��m, n = 3; holotype: 400 ��m, measured from tip of rostrum to posterior margin of caudal rami). Maximum width ranged from 132 to 136 ��m (mean 134 ��m, n = 3; holotype: 135 ��m, measured at posterior margin of cephalothorax). Boundary between prosome and urosome clearly visible, urosome/prosome length ratio 0.62, and body length/width ratio about 3.1. Body ornamentation (Fig. 10A, B) as in N. minutus. Cephalothorax (Figs. 9A, 10A, B) anteriorly attenuated in dorsal view, 0.9 times as long as wide, comprising 38% of total body length, with several paired sensilla as figured, 1 row of sensilla along serrated posterior margin, and 1 medial integumental window close to posterior margin dorsally (arrowed in Fig. 10B). Rostrum (Fig. 9C) as in N. minutus and with pair of sensilla anteriorly. Prosome (Fig. 9A) 4-segmented, comprising cephalothorax and 3 subequal free pedigerous somites. P1- bearing somite fused to cephalothorax, posterior margin of free pedigerous somites serrated, and with row of sensilla as figured. Urosome (Figs. 9A, 12A) tapering posteriorly, consisting of P5-bearing somite, genital double-somite, 2 abdominal somites, and anal somite. P5-bearing somite and first half of genital double-somite with serrated posterior margin dorsolaterally, and sensilla along posterior margin dorsally except for penultimate urosomite. Genital double-somite, following 2 urosomites with serrated posterior margin dorsally and ventrally, and with additional medial row of spinules ventrally. Genital double-somite (Figs. 9A, 12A) almost 1.4 times as wide as long (ventral view), completely fused ventrally, with original segmentation indicated by serrated surface ridge dorsally, and copulatory pore located between both P6 with median depression. Anal somite (Figs. 10A, 12A���C) almost as long as width with well-developed operculum, dense carpet of setules, pair of dorsal sensilla and pore, setules and denticles produced randomly, and 1 row of spinules on either side of anal segment ventrally. Caudal rami (Figs. 10C, D, 12A���C) cylindrical, 1.8 times as long as wide in dorsal and ventral view, and ornamentation consisting of setules (Fig. 10C, D). Each ramus bearing 7 setae: seta I naked, shorter than ramus width, and located anterodorsally; seta II naked, as long as ramus width, and inserted anterodorsally midway along inner margin; seta III bipinnate, almost as long as ramus length, and anterolaterally midway along outer margin; seta IV bipinnate, 0.27 times as long as seta V, located at outer margin distally (arrowed in Fig 12A) but inserted at dorsal proximal area of seta V (visible in lateral view, arrowed in Fig. 12C), and with globular expansion at proximal region (arrowed in Fig. 12A, B); seta V strongest, bipinnate, located at distal inner margin, inflated, and extremely bulbous at proximal region; seta VI small, and naked; seta VII triarticulate, naked, and located midway along inner margin. Antennule, antenna, and mouth parts as in N. minutus. P1���P4 (Fig. 11A���E) with smooth and short concave intercoxal sclerite (not illustrated). Praecoxa somewhat triangular and shorter than coxa, and with 1 row of outer spinules (P1, P2 and P4). Coxa with 1 spinular row on anterior surface, and row of outer strong spinules (P1, P2, P3 and P4). Basis with 1 row of strong outer spinules near insertion of exopod, and 1 row of distal spinules near insertion of endopod (P1, P2, P3 and P4). Basal outer seta naked (P1 and P2) or bipinnate (P3 and P4), and P1 with inner strong pinnate spine. Exopod 3-segmented, all segments subequal in length, and with spinules and setules along outer and inner margins as figured. Endopod 2- segmented in P1, P2 and P3 or 1-segmented in P4. All setae on P1���P4 endopods pinnate. Armature formula as in N. minutus. FIGURE 11. Nannopus dimorphicus sp. nov., line drawings, A���C & E���F, paratype ♂ 1; D, paratype ♂ 2: A, P1; B, P2; C, P3; D, left P3 endopod; E, P4; F, P5. P5 (Fig. 11F) with separate baseoendopod and exopod. Baseoendopod transversely elongated, with 1 row of spinules along inner distal margin, and endopodal lobe with 2 pectinate and 2 pinnate setae. Exopod squarish, almost as long as width, and with 5 pinnate setae (innermost element longest and fused to segment). P6 (Fig. 12A, D) with semi circular flap bearing 1 small pinnate distal seta. Description of male (based on allotype and paratypes). Body (Fig. 13A) as in female, total body length ranged from 325 to 410 ��m (mean = 377 ��m, n = 2; allotype: 325 ��m, measured from tip of rostrum to posterior margin of caudal rami). Maximum width ranged from 119 to 125 ��m (mean 122 ��m, n = 2; allotype: 120 ��m, measured at posterior margin of cephalothorax). Urosome/prosome length ratio 0.5 in dorsal view and body length/ width ratio about 2.5 in dorsal view. Cephalothorax (Figs. 13A, 14B) 0.8 times as long as wide, comprising 29% of total body length, and with 1 integumental window as in female (arrowed in Fig. 14B). Body ornamentation (not illustrated), anal somite (Fig. 13A), rostrum (Fig.13A), and P1 (not illustrated) as in female. Antennule (not illustrated) as in male N. minutus. Antenna (not illustrated) and mouth parts (not illustrated) as in N. minutus. Prosome 4-segmented (Fig. 13A), comprising cephalothorax (bearing first pedigerous somite), and 3 free somites. Posterior margin of prosomites serrated, and with sensilla as in female. Urosome 6-segmented (Fig. 13A, B), comprising P5-bearing somite, genital somite, 3 free abdominal somites and anal somite. Posterior margin of urosomites serrated except for anal somite, and with sensilla as in female. P6- bearing somite, and urosomite 3 to 5 with longitudinal row of spinules along posterior margin ventrally. Genital somite (Fig. 13A, D) homologous to anterior part of genital double-somite in female, and second and third urosomite well segmented in ventral view. Posterior margins of each somite serrated dorsally with few sensilla. Caudal rami (Figs. 13A���D, 14C���D) almost as in female except for seta IV and V without modifications (normal type) at its base. P2���P4 (Fig. 15A���D). P2 praecoxa without spinules. P4 basis without spinules near insertion of endopod, and with inner setules. Apical outer spine of exp- 3 in P2���P3 with inner setules, and 1 subdistal spinule on distal outer spine of exp- 3 in P3. Endopod 2-segmented in P2 and P3 or 1-segmented in P4. P2 enp-1 with distal spinules. P3 enp-2 with short inner pinnate seta (arrowed in Fig. 15B), and outer spine fused to enp-2 forming sharp apophysis (arrowed in Fig. 15C). P4 endopod with naked inner seta. P5 (Fig. 13E) baseoendopod confluent with somite, and spinules along posterior margin. Endopodal lobe armed with 2 pectinate, and 2 naked setae. Exopod completely fused with baseoendopod, and with 5 elements (4 bipinnate, and 1 naked setae, and outer most one smallest). P6 (Fig. 13F) asymmetrical, only right flap operational, and with 3 bipinnate setae (medial one longest)., Published as part of Vakati, Vinod & Lee Wonchoel, 2017, Five new species of the genus Nannopus (Copepoda: Harpacticoida: Nannopodidae) from intertidal mudflats of the Korean West Coast (Yellow Sea), pp. 1-66 in Zootaxa 4360 (1) on pages 15-22, DOI: 10.11646/zootaxa.4360.1.1, http://zenodo.org/record/1069253

Genus Nannopus Brady, 1880 Redefined diagnosis. Body fusiform, ovate or cylindrical, and dorsoventrally depressed somites with 2 egg sacs. Rostrum fused at base, prominent, deeply recurved downwards, anterior margin densely hirsute. Anal somite with pair of dorsal sensilla, with or without pair of dorsal pore, and anal operculum with dense carpet of setules. Caudal rami small, rectangular, or sub-rectangular, and with 7 setae. Antennule 5-segmented in female and 6 to 7- segmented in male. Antenna with at most 2 abexopodal setae on allobasis, and exopod 1-segmented. Mandible uniramous, exopod and endopod fused, and with 4 to 5 setae. Maxillule praecoxal arthrite with at most 8 sturdy spines/setae and 1 to 2 pinnate recurved setae at distal margin. Maxillary syncoxa with 2 endites bearing 3 elements, allobasis with claw and 1 accompanying seta, and endopod incorporated into basis represented by 2 setae. Maxilliped syncoxa with 1 distal seta, endopod 2-segmented, and distal segment with 1 claw and 2 accessory setae at proximal region. P1���P4 exopod 3-segmented. P1���P3 endopod at most 2-segmented and P4 endopod 1- segmented. P3 enp-2 with distal apophysis in males. P4 exp-3 with or without inner subdistal pectinate seta. P5 exopod separated or fused to baseoendopod in female, always fused in males, both baseoendopods confluent or separated in females, and always confluent in males. P5 exopod with 4���5 setae, endopod with 3���4 setae. P6 with 1 seta set on peduncle in female, and 2���3 setae in males., Published as part of Vakati, Vinod & Lee Wonchoel, 2017, Five new species of the genus Nannopus (Copepoda: Harpacticoida: Nannopodidae) from intertidal mudflats of the Korean West Coast (Yellow Sea), pp. 1-66 in Zootaxa 4360 (1) on page 5, DOI: 10.11646/zootaxa.4360.1.1, http://zenodo.org/record/1069253, {"references":["Brady, G. S. (1880) A Monograph of the Free and Semi-parasitic Copepoda of the British Islands. 2. The Ray Society, London, 182 pp."]}

Vakati, Vinod, Lee Wonchoel (2017): Five new species of the genus Nannopus (Copepoda: Harpacticoida: Nannopodidae) from intertidal mudflats of the Korean West Coast (Yellow Sea). Zootaxa 4360 (1): 1-66, DOI: https://doi.org/10.11646/zootaxa.4360.1.1

Nannopus serratus sp. nov. (Figs. 16���22) Type locality. Intertidal mudflat, Gilsang-myeon, Ganghwa Island, South Korea, Yellow Sea, 37��35'55.9"N 126��30'49.2"E (Fig. 1A, B). Type material. Holotype: 1 female in 70% ethanol (NIBRIV0000753985). Allotype: 1 male in 70% ethanol (NIBRIV0000810841). Paratypes: 2 females dissected on 5 and 2 slides (NIBRIV0000810838 ��� 39), 2 males dissected on 1 and 1 slides (NIBRIV0000810842 ��� 43); 2 females and 1 male on SEM stub (NIBRIV0000810840). All samples were collected by Vinod Vakati, 20 November 2013. Etymology. The species epithet is derived from the Latin ��� serratus ��� referring to the strong bipinnate spines on the antennary endopod, and outer exopodal spines of P1���P 4 in both sexes. Description of female (based on holotype and paratypes). Body fusiform (Fig. 16A, B) narrow, total body length ranged from 556 to 566 ��m (mean = 562 ��m, n = 3; holotype: 566 ��m, measured from tip of rostrum to posterior margin of caudal rami). Maximum width ranged from 166 to 173 ��m (mean 169 ��m, n = 3; holotype: 166 ��m, measured at posterior margin of cephalothorax). Body slightly slender, tapering towards posterior, and inner cuticle relatively thicker. Urosome/prosome length ratio 0.73 (Fig. 16A) and body length/width ratio about 3.4. Body ornamentation (Figs. 17A���F, 19A���D) almost as in N. minutus except for denticles arranged in unique pattern of patches on cephalothorax and anal somite. Each urosomite with rows of slim setules ventrally (Fig. 17F). Cephalothorax (Fig. 16A) bell shaped, slightly narrow, 0.8 times as wide as long, comprising 31% of total body length, with several paired sensilla, and serrated posterior margin. Rostrum (Fig. 16B, C) prominent, deeply recurved downward than in N. minutus, anterior margin densely hirsute, and with 1 pair of dorsal sensilla (not visible in dorsal view). Prosome (Fig. 16A, B) 4-segmented, comprising cephalothorax and 3 subequal free pedigerous somites. P2- bearing somite with 2 long medial sensilla dorsally, posterior margins of prosomites serrated, and with few sensilla as figured. Urosome (Figs. 16A, B, 17E, 20A) 5-segmented, comprising P5-bearing somite, genital double-somite, 2 free abdominal somites and anal somite. Posterior margins of urosomites serrated dorsally and ventrally. Posterior margin of genital double-somite and following somite with pair of strong sensilla ventrally (arrowed in Fig 20A). Each somite with transverse row of spinules along posterior margin ventrally. Lateral margin of second to fourth urosomites with small projection (Figs. 16B, arrowed in 17E). Genital double-somite (Fig. 20A) 1.6 times as wide as long, completely fused ventrally, clearly distinct dorsally, with serrated dorsal posterior margin, copulatory pore located between both P6, and with slight median depression. Anal somite (Figs. 19A���D, 20A, C) almost as long as width with unique pattern of surface ornamentation dorsally and ventrally. Caudal rami (Figs. 19A���D, 20A���C) square (dorsally) or sub-cylindrical (ventrally) shaped, as long as wide (in dorsal view), twice as long as wide (in ventral view), and with row of spinules along posteroventral margins. Caudal ramus bearing 7 setae: seta I pinnate, shorter than ramus width, and located anterolaterally; seta II pinnate, almost as long as ramus length, and inserted anterolaterally midway along outer margin; seta III pinnate, as long as ramus length, and inserted anterolaterally midway along outer margin; seta IV slender, bipinnate, 0.4 times as long as seta V, located at outer posterior margin, and wide at proximal region; seta V strongest, bipinnate with proximal part rather wide and smooth, and located at inner posterior margin; seta VI pinnate, small, and located at inner posterior corner; seta VII slender, flexible, triarticulate, pinnate, located midway along inner margin, and relatively longer than in N. minutus. Antennule, maxillule, maxilla, and maxilliped as in N. minutus. Antenna (Fig. 16D) same as in N. minutus except for endopod with few spinules at outer distal corner, spines rigid and blunt than in N. minutus. All distal spines denticulated except for inner subdistal spine. Exopod 1.3 times as long as width, and with 4 naked elements. Mandible (Fig.16E) same as in N. minutus except for mandibular palp with 1 basal (pinnate), 1 endopodal (naked seta arising from stem like protrusion), and 3 exopodal elements (2 pinnate and 1 naked). P1���P4 (Fig. 18A���E) with smooth and short concave intercoxal sclerite (not illustrated). Praecoxa somewhat triangular and shorter than coxa, distal margin smooth (P2, P3 and P4) or ornamented with 1 row of spinules (P1). Coxa with 1 spinular row on anterior surface and with 1 row of strong outer spinules. Basis with 1 row of strong outer spinules near insertion of exopod, and 1 row of distal spinules near insertion of endopod except for P4. P1 with row of distal spinules near insertion of inner spine. Basal outer seta naked (P1, P2 and P4) or bipinnate (P3), and inner pinnate spine present on P1. Exopod 3-segmented, and all segments subequal in length. Each exopodal segment with robust outer spinules except for P3 exp-3. Exp-1 to -3 (P1 and P2) and exp-1 to -2 (P4) with row of inner setules. P2 and P3 exp-2 with pinnate inner setae. Exp-3 (P1, P2, P3 and P4) with pinnate inner subdistal, distal, and outer terminal setae. P4 exp-3 with 1 inner subdistal pectinate seta. Endopod 1-segmented in P1 and P4 or 2-segmented in P2 and P3. P1 endopod, P2 enp-2 and P3 enp-1 with robust outer distal spinules. P1 endopod with inner setules. All endopodal setae on P1���P4 pinnate except for naked inner short seta on P4 endopod (Fig. 18E). Armature formula as follows: P5 (Fig. 20D) with separate baseoendopod and exopod. Baseoendopod transversely elongated, confluent with somite, almost rectangular, and scattered setules along anterior surface. Endopodal lobe with 1 pectinate and 2 bipinnate setae. Exopod squarish, almost as long as width, and with rows of setules and 4 pinnate setae (innermost element longest, strongest, bipinnate and fused to exopod). P6 (Fig. 20A, E) linguiform and outer distal edge bearing 1 pinnate seta. Description of male (based on allotype and paratypes). Body (Fig. 21A) as in female except for total body length ranged from 492 to 594 ��m (mean = 538 ��m, n = 2; allotype: 528 ��m, measured from tip of rostrum to posterior margin of caudal rami). Maximum width ranged from 163 to 178 ��m (mean 171 ��m, n = 2; allotype: 172 ��m, measured at posterior margin of cephalothorax). Urosome/prosome length ratio 0.86 (Fig. 21A) and body length/width ratio about 3.7. Cephalothorax (Fig. 21A) as in female except for 1.1 times as long as wide and comprising 30.7% of total body length. Body ornamentation (not illustrated), anal somite (Fig. 21A), caudal rami (Fig. 21A���D), rostrum (not illustrated), antenna (not illustrated), mandible (not illustrated), P1 and P4 (not illustrated) as in female. Antennule (not illustrated) as in male N. minutus and remaining mouth parts (not illustrated) as in N. minutus. Prosome 4-segmented (Fig. 21A), comprising cephalothorax (bearing first pedigerous somite), and 3 free somites. Posterior margin of prosomites serrated and with sensilla as in female except for second prosomite without long sensilla. Urosome 6-segmented (Fig. 21A, B), comprising P5-bearing somite, genital somite, 3 free abdominal somites, and anal somite. Posterior margin of urosomites serrated except for anal somite, and with sensilla as in female. Urosomite 3 to 5 with longitudinal row of spinules along posterior ventral margin. Genital somite (Fig. 21B) homologous to anterior part of genital double-somite in female, and second and third urosomites clearly segmented ventrally. P2���P3 (Fig. 22A, B) with smooth and short concave intercoxal sclerite (not illustrated). Exopod 3-segmented. P2 exopod more robust than in female and P2 exp-3 outer spines stronger than in female (arrowed in Fig. 22A). P3 exopod as in female except for exp-3 with outer spinules. P3 enp-1 without outer spinules. P3 enp-2 modified with outer spine fused to segment forming bipinnate apophysis, 1 short naked inner, and 1 long pinnate distal setae. P5 (Fig. 22C) baseoendopod confluent with somite. Endopod with 1 pectinate and 2 naked setae (arrowed in Fig. 22C). Exopod fused with baseoendopod bearing 4 elements (3 pinnate and 1 naked), and 2 medial setae subequal in length (arrowed in Fig. 22C). P6 (Figs. 21B, 22D) asymmetrical with simple operational flap at left side and each flap with 2 short naked setae., Published as part of Vakati, Vinod & Lee Wonchoel, 2017, Five new species of the genus Nannopus (Copepoda: Harpacticoida: Nannopodidae) from intertidal mudflats of the Korean West Coast (Yellow Sea), pp. 1-66 in Zootaxa 4360 (1) on pages 22-31, DOI: 10.11646/zootaxa.4360.1.1, http://zenodo.org/record/1069253

Nannopus bulbiseta sp. nov. (Figs. 32���38) Type locality. Intertidal mudflat, Yangdo-myeon, Ganghwa Island, South Korea, Yellow Sea, 37��40'08.4"N 126��24'20.9"E (Fig. 1A, B). Type material. Holotype: dissected on 2 slides (NIBRIV0000753987). Allotype: dissected on 2 slides (NIBRIV0000810823). Paratypes: 3 females dissected on 2, 2 and 1 slides (NIBRIV0000810820, 22, 24), and 1 male dissected on 1 slides (NIBRIV0000810827), 1 female in 70% ethanol (NIBRIV0000810821), 1 male in 70% ethanol (NIBRIV0000810826), and 2 females and 2 males together on SEM stub (NIBRIV0000810825). All samples were collected from the type locality by Vinod Vakati, 5 March 2015. Etymology. The specific epithet refers to the bulbous shape of caudal seta V in female. Description of female (based on holotype and paratypes). Body (Fig. 32A) fusiform, total body length ranged from 416 to 455 ��m (mean = 437 ��m, n = 4; holotype: 455 ��m, measured from tip of rostrum to posterior margin of caudal rami). Maximum width ranged from 161 to 152 ��m (mean = 159 ��m, n = 4; holotype: 165 ��m, measured at posterior margin of cephalothorax). Boundary between prosome and urosome clearly present, urosome/prosome length ratio 0.36, and body length/width ratio about 2.6. Surface ornamentation as in N. parvus. Cephalothorax (Fig. 32A) almost as long as width, comprising 34.1% of total body length, posterior margin serrated, and with several sensilla, and denticles. Rostrum as in N. parvus. Prosome (Fig. 32A, B, 33A) 4 segmented, comprising cephalothorax, and 3 pedigerous somites. All prosomites subequal, serrated posterior margins, and with row of sensilla. P2 and P3 bearing prosomites with very long sensilla on either side of dorsolateral margins, and P2-bearing somite with 1 row of short frills along anterior margin (Figs. 32A, arrowed in 33A). Urosome (Figs. 32A, B, 33B, 35C) 5-segmented, posteriorly tapering, comprising P5-bearing somite, genital double-somite, 2 free abdominal somites, and anal somite. Posterior margins of urosomites serrated dorsally and ventrally. Row of sensilla along posterior margins dorsally except for penultimate somite. Row of spinules on third somite ventrally. Genital double-somite (Figs. 32B, 33B, 35C) 2.4 times wider than long (ventral view), with original segmentation indicated by transverse, serrated surface ridge dorsally, and completely fused ventrally. Copulatory pore located medially, and with round shape. Anal somite (Figs. 32A, 33D) twice wider than long, with well-developed operculum presenting row of dense setules along distal margin, 1 pair of dorsal sensilla, and denticles scattered randomly. Caudal rami (Fig. 35A���C) nearly incorporated into anal somite but with clear separation between anal somite and each ramus. Medial spinular row located midway of outer margin laterally and ventrally. Distal spinular row dorsally and ventrally, and 0.9 (dorsal view) and 1.9 (ventral view) times as long as width. Caudal ramus bearing 7 setae: seta I naked, shorter than ramus width, and located dorsolaterally at anterior region; seta II naked, almost as long as ramus length, and located anterodorsally; seta III naked, almost as long as ramus length, and located laterally along posterior region; seta IV naked, 0.3 times as long as seta V, located at outer posterior margin, and proximal area slightly inflated; seta V longest, pinnate, bulbous anteriorly, and extremely thin posterior half; seta VI pinnate, almost as long as seta II and III; seta VII biarticulate, pinnate, and located at midway along inner margin. Antennule, Antenna, and mouth parts as in N. parvus. P1���P4 (Fig. 34A���E) with smooth and short concave intercoxal sclerite (not illustrated). Praecoxa somewhat triangular, shorter than coxa, and ornamented with row of spinules in P1. Coxa with 1 spinular row (P1, P2 and P3) on anterior surface, and row of strong outer spinules (P1, P2 and P4). Basis with row of strong outer spinules near insertion of exopod, and row of distal spinules near insertion of endopod (P1, P2, P3 and P4). Row of inner spinules (P1) or setules (P2 and P3). Basal outer seta naked (P1 and P2) or bipinnate (P3 and P4). Basal inner robust spine present on P1. P3 outer basal setae very robust and reaching to distal margin of exp-3. Exopod 3- segmented, and all segments sub-equal. Exp-1 to -2 (P1) and exp-1 to -3 (P2, P3 and P4) with robust outer spinules. Exp-1 to -2 (P1, P3 and P4) and exp-1 (P2) with row of inner setules. Exp-1 to -3 (P1���P3) with pinnate outer spines. Exp-2 (P2 and P3) with pinnate inner setae. Exp-3 (P1, P2, P3 and P4) with pinnate inner subdistal, distal and outer terminal setae. P4 exp-3 with short inner subdistal pectinate spine (Paratype presenting 1 minute spinule along inner margin near distal end, fig. 34D). Endopod 2-segmented in P1, P2 and P3 or 1-segmented in P4. Enp-2 (P1 and P3) with robust outer distal spinules, and enp-2 (P1 and P3) with row of inner setules. Setae on endopods of P1���P4 mostly pinnate except for 2 naked inner setae on enp-2 of P2���P3, and inner apical small seta of P4 endopod. Armature formula as follows: P5 (Fig. 35D) almost as in N. parvus except for endopod with 2 inner sub-equal pectinate spines, and 2 small sub-equal naked setae. Exopod with 2 pinnate and 2 naked setae. P6 (Fig. 35C, E) as in N. parvus. Male (based on allotype and paratypes). Body (Fig. 36A) smaller than female, body length ranged from 411 to 386 ��m (mean = 401 ��m, n = 3; allotype: 408 ��m, measured from tip of rostrum to posterior margin of caudal rami). Maximum width ranged from 137 to 152 ��m (mean 149 ��m, n = 3; allotype: 137 ��m, measured at posterior margin of cephalothorax). Urosome/prosome length ratio 0.5 and body length/width ratio about 2.8. Cephalothorax (Fig. 36A) almost as in female, as long as wide, and comprising 36.2% of total body length. Body ornamentation (Fig. 36A), anal somite (Fig. 36A), rostrum (not illustrated), P1���P2 (not illustrated) as in female. Antennule (not illustrated) as in male N. parvus, antenna (not illustrated), and other mouth parts (not illustrated) as in N. parvus. Prosome 4-segmented (Fig. 36A), comprising of cephalothorax (bearing first pedigerous somite), and 3 free somites. Posterior margin of prosomites serrated, and with sensilla as in female. Urosome 6-segmented (Fig. 36A, B), comprising of P5-bearing somite, genital somite, 3 free abdominal somites and anal somite. Posterior margin of urosomites serrated except for anal somite, and with sensilla as in female. Urosomite 3 to 5 with longitudinal row of spinules near ventral posterior margin. Genital somite (Fig. 36A) homologous to anterior part of genital double-somite in female, second and third urosomites well segmented in ventral view. Caudal rami (Fig. 36B, D) almost as in female except for seta V inflated with globular expansion at its insertion site. P3���P4 (Fig. 38A���F) intercoxal sclerite, praecoxa, coxa, basis, and ornamentation of setae on endopods as in female. P3 outer basal seta reduced (half as long as in female), P3 enp-2 outer spine fused to segment forming apophysis armed blunt tip, slightly curved along outer margin (arrowed in Fig. 38A, B), and 2 pinnate setae (1 long, and 1 short arrowed in Fig. 38A, B). P4 basal seta naked, endopod distal pinnate seta shorter than in female, and only reaching distal margin of exp-3 (Fig. 38C). P5 (Fig. 38D) fused with somite, exopod and baseoendopod fused, and both baseoendopods confluent. Endopodal lobe with 2 sub-equal small pectinate spines, 2 sub-equal small naked setae, and rows of spinules near posterior margin. Exopodal lobe bearing 2 pinnate and 2 naked setae. P6 (Figs. 36B, 38E) asymmetrical, with functional flap located at left side, with some spinules along posterior margin, with 3 setae (1 bipinnate and 2 naked), and median one twice as long as remaining 2 setae., Published as part of Vakati, Vinod & Lee Wonchoel, 2017, Five new species of the genus Nannopus (Copepoda: Harpacticoida: Nannopodidae) from intertidal mudflats of the Korean West Coast (Yellow Sea), pp. 1-66 in Zootaxa 4360 (1) on pages 41-49, DOI: 10.11646/zootaxa.4360.1.1, http://zenodo.org/record/1069253

Nannopus parvus sp. nov. (Figs. 23–31) Type locality. Intertidal mudflat, Yangdo-myeon, Ganghwa Island, South Korea, Yellow Sea, 37°40'08.4"N 126°24'20.9"E (Fig. 1A, B). Type material. Holotype: 1 female adult in 70% ethanol (NIBRIV0000753986). Allotype: 1 male adult in 70% ethanol (NIBRIV0000810848). Paratypes: 3 females dissected on 6, 3 and 2 slides (NIBRIV0000810844 – 46), and 1 male dissected on 4 slides (NIBRIV0000810849); 3 females and 3 males together on SEM stub (NIBRIV0000810847). All samples were collected from the type locality by Vinod Vakati, 5 March 2015. Etymology. The species epithet is derived from the Latin “ parvus ” referring to the small caudal seta V in both sexes. Description of female (based on holotype and paratypes). Body fusiform (Fig. 23A, B), total length ranged from 404 to 416 µm (mean = 428 µm, n = 4; holotype: 404 µm, measured from tip of rostrum to posterior margin of caudal rami). Maximum width ranged from 136 to 168 µm (mean = 151 µm, n = 4; holotype: 145 µm, measured at posterior margin of cephalothorax). Boundary between prosome and urosome clearly visible, urosome/prosome length ratio 0.7 and body length/width ratio about 2.7. Body ornamentation (Fig. 23A, B, 24A–D, 26C, 27A, B) consisting of dorsal denticles, and 2 to 3 transverse rows of denticles in unique pattern. P2-bearing somite with 1 transverse row of frill anteriorly. Urosomites with horizontal row of setules ventrally (Fig. 27A). Anal somite with 1 or 2 horizontal row of setules (Figs. 23A). Cephalothorax (Fig. 23A) bell shaped, almost as long as wide, comprising 35.4% of total body length, with few paired sensilla, and posterior margin serrated. Rostrum (Fig. 23B, C) triangular with round tip, with pair of dorsal sensilla, recurved downward as in N. minutus, and terminal margin densely hirsute. Prosome (Fig. 23A, B) 4-segmented, comprising cephalothorax and 3 subequal free pedigerous somites. P1- bearing somite fused to cephalothorax, pedigerous somites serrated, and row of sensilla posteriorly. P2-bearing somite with pair of very long sensilla. Urosome (Figs. 23A, B, 26C) 5-segmented, posteriorly tapering, comprising P5-bearing somite, genital double-somite, 2 free abdominal somites, and anal somite. Posterior margins serrated dorsally and ventrally. Each somite with row of sensilla along dorsal posterior margin except for penultimate somite, and row of spinules along ventral posterior margin. Genital double somite (Figs. 23B, 26C) 2.2 times wider than long, with original segmentation indicated by transverse, serrated surface ridge dorsally, and completely fused ventrally. Copulatory pore located medially, and with obscure shape. Anal somite (Figs. 23A, 26A) twice wider than long, with well-developed anal operculum presenting dense carpet of setules along posterior margin, and pair of dorsal sensilla. Caudal rami (Figs. 26A–C, 27A, B) trapezoidal or square shaped (ventral view), 1.2 to 1.3 times as long as width, with 1 medial spinular row at midway of outer margin laterally and ventrally, and distal spinular row dorsally and ventrally. Caudal ramus bearing 7 setae: seta I naked, shorter than ramus width, and located anterolaterally; seta II naked, almost as long as ramus width, and located dorsolaterally at midway along outer margin; seta III bipinnate, almost as long as ramus length, and located posterolaterally; seta IV bipinnate, stout, 0.2 times as long as seta V, and located at outer posterior margin; seta V strongest, bipinnate, with anterior part rather wide and smooth, located at inner posterior margin, and spine-shaped; seta VI bipinnate and almost as long as seta I; seta VII biarticulate, pinnate, and located at midway along dorsal side. Antennule (Figs. 25A) almost as in N. minutus except for segments 2 and 4 presenting cluster of tiny setules. Segment 2 with 5 pinnate setae (2 setae proximally bulbiform, arrowed in Fig. 25A). Armature formula: 1-[1], 2-[4 + 5 pinnate], 3-[6+ (1 + ae)], 4-[1], 5-[8 + acrothek]. Antenna (Fig. 25B) almost as in N. minutus except for abexopodal setae ornamentation (1 pinnate and 1 naked). Mandible (Fig. 25C) almost as in N. minutus except for mandibular palp size (relatively broad), with 5 setae [1 basal (pinnate), 3 exopodal (2 pinnate and 1 naked), and 1 endopodal (naked)]. Maxillule (Fig. 25D) almost as in N. minutus except for total number of elements along distal margin of praecoxal arthrite (8 stout naked spines/setae and 1 bipinnate seta). Ornamentation of 5 basal setae naked. Maxilla (Fig. 25E) almost as in N. minutus except for elements of syncoxal endites without spinular ornamentation at distal margin. Maxilliped (Fig. 25F) almost as in N. minutus except for length of 1 accessory seta (reaching to distal margin of claw) at proximal region of distal endopod segment. P1–P4 (Fig. 28A–D) with smooth and short concave intercoxal sclerite (not illustrated). Praecoxa somewhat triangular, shorter than coxa, and without spinules except for P1. Coxa with 1 spinular row (P2, P3 and P4) on anterior surface, and row of strong outer spinules (P1, P2, P3 and P4). Basis with row of strong outer spinules near insertion of exopod, and row of very small (P1) and long distal spinules (P1, P2, P3 and P4) near insertion of endopod. Additional ornamentations including row of inner spinules (P1) or setules (P2 and P3). Outer seta naked (P1 and P2) or bipinnate (P3 and P4), and inner spine present on P1. Exopod 3-segmented, all segments subequal, and exp-1 to -3 (P1, P2, P3 and P4) with robust outer spinules. Exp-1 to -3 (P1 and P3), and exp-1 to -2 (P4) with row of inner setules. Exp-1 to -3 (P1, P2 and P3) and exp-2 to -3 (P4) with pinnate outer spines. Exp-2 (P2, P3 and P4), and exp-3 (P1, P2, P3 and P4) with pinnate inner subdistal, distal and outer terminal setae. P4 exp-3 with short inner subdistal pectinate spine. Endopod 2-segmented in P1–P3 or 1-segmented in P4. Enp-1 to -2 (P1, P2 and P3) with robust outer distal spinules. Enp-1 to -2 (P1), and enp-2 (P3) with row of inner setules. All setae on P1, P2, P3 and P4 endopods pinnate including inner apical short seta on P4 endopod (Fig. 28D). Armature formula as follows: P5 (Fig. 26D) fused with somite, exopod and baseoendopod fused, both baseoendopod confluent, and baseoendopod with inner spinules posteriorly. Endopodal lobe with 2 pectinate (1 short and 1 extremely long), and 2 small sub-equal naked setae. Exopodal lobe with 4 pinnate setae. P6 (Fig. 26C, E) with small triangular flap, and each flap bearing 1 small distal naked seta. Description of male (based on allotype and paratypes). Body (Fig. 29A) as in female except for total body length ranged from 426 to 313 µm (mean = 369 µm, n = 2; allotype: 313 µm, measured from tip of rostrum to posterior margin of caudal rami). Maximum width ranged from 132 to 156 µm (mean 144 µm, n = 2; allotype: 132 µm, measured at posterior margin of cephalothorax). Urosome/prosome length ratio 0.6 and body length/width ratio about 3.1. Cephalothorax (Fig. 29A) almost as in female, as long as width, and comprising 31.2% of total body length. Body ornamentation (Fig. 29A), anal somite (Fig. 29A), rostrum (not illustrated), antenna (not illustrated), mouth parts (not illustrated), P1–P2, and P4 (not illustrated) as in female. Prosome 4-segmented (Fig. 29A), comprising cephalothorax (bearing first pedigerous somite), and 3 free somites. Posterior margin of prosomites serrated, and with sensilla as in female. Urosome 6-segmented (Fig. 29A, B) comprising of P5-bearing somite, genital somite, 3 free abdominal somites, and anal somite. Posterior margin of urosomites serrated except for anal somite, and with sensilla as in female. Urosomite 3 to 5 with longitudinal row of spinules along ventral posterior margin. FIGURE 28. Nannopus parvus sp. nov., line drawings, A–B & D, paratype ♀ 1; C, paratype ♀ 2: A, P1; B, P2; C, P3; D, P4. Genital somite (Fig. 29B) homologous to anterior part of genital double-somite in female, second and third urosomite well segmented in ventral view. Caudal rami (Fig. 29B, C, D) presenting seta IV sparsely pinnate and slender, seta V shorter than in female, and seta VI and VII naked. Antennule (Figs. 30C, 31A, B) chirocer, 7-segmented with strong geniculation between segments 5 and 6. Segment 4 representing by small incomplete segment with only 1 naked seta. Armature formula as follows: 1-[1], 2-[4 + 5 pinnate], 3-[3], 4-[1], 5-[6], 6-[9 + (1+ae)], 7-[7 + acrothek]. Apical acrothek consisting of minute aesthetasc and 2 naked setae. P3 (Figs. 30D, 31C, D, E) exopod 3-segmented, and exp-1 to -2 with row of inner setules. Endopod 2- segmented, enp-2 outer spine fused to segment forming short apophysis with sharp and curved tip, and inner 2 setae pinnate as in female. P5 (Fig. 31F) fused with somite, exopod and baseoendopod fused, and both baseoendopods confluent. Baseoendopod with inner spinules, and row of setules posteriorly. Endopodal lobe with 2 sub-equal pectinate setae (outer pectinate seta 0.3 times as long as one in female, arrowed in fig. 31F) and 2 sub-equal naked setae. Exopodal lobe with 4 unequal elements [outermost and innermost setae naked (arrowed in Fig. 31F) and medial 2 setae bipinnate]. P6 (Figs. 29B, 31G) asymmetrical with small functional flap on left side, with 3 elements (2 bipinnate and 1 naked), and median element longer than remaining 2 elements.