taxonID	type	description	language	source
F1F81C8F06275EBB8634327E44E29C2A.taxon	materials_examined	Material examined. Holotype: MABIKNA 00155561, sex uncertain, Yeonggwang, 35 ° 25.819 ' N, 126 ° 25.482 ' E, intertidal, tidal mud-flat, 1 m depth, November 2017, coll. Man-Ki Jeong. Paratypes (2 specimens): MABIK NA 00155562 and NA 00155563, same information as holotype.	en	Jeong, Man-Ki, Soh, Ho Young, Suh, Hae-Lip (2019): Three new species of Heteromastus (Annelida, Capitellidae) from Korean waters, with genetic evidence based on two gene markers. ZooKeys 869: 1-18, DOI: http://dx.doi.org/10.3897/zookeys.869.34380, URL: http://dx.doi.org/10.3897/zookeys.869.34380
F1F81C8F06275EBB8634327E44E29C2A.taxon	materials_examined	Additional material examined. MABIK NA 00155564, sex uncertain, Yeonggwang, 35 ° 25.819 ' N, 126 ° 25.482 ' E, intertidal, tidal mud-flat, 1 m depth, May 2015, coll. Man-Ki Jeong. Additional 16 specimens from type locality on SEM stub.	en	Jeong, Man-Ki, Soh, Ho Young, Suh, Hae-Lip (2019): Three new species of Heteromastus (Annelida, Capitellidae) from Korean waters, with genetic evidence based on two gene markers. ZooKeys 869: 1-18, DOI: http://dx.doi.org/10.3897/zookeys.869.34380, URL: http://dx.doi.org/10.3897/zookeys.869.34380
F1F81C8F06275EBB8634327E44E29C2A.taxon	diagnosis	Diagnosis. Abdominal hooks with four rows of teeth; three teeth in basal row, three in second row, four in third row, and two in superior row. Genital pores present in intersegmental furrows of between chaetigers 5 - 6, 6 - 7, 7 - 8, 8 - 9, 9 - 10, and 10 - 11. Posteriorly extended parapodial lobes absent on abdominal segments.	en	Jeong, Man-Ki, Soh, Ho Young, Suh, Hae-Lip (2019): Three new species of Heteromastus (Annelida, Capitellidae) from Korean waters, with genetic evidence based on two gene markers. ZooKeys 869: 1-18, DOI: http://dx.doi.org/10.3897/zookeys.869.34380, URL: http://dx.doi.org/10.3897/zookeys.869.34380
F1F81C8F06275EBB8634327E44E29C2A.taxon	description	Description. Holotype entire, about 26 mm long, 0.5 mm wide for 120 chaetigers. Paratypes range from 19 - 24 mm in length, 0.4 - 0.5 mm width for 75 - 110 chaetigers. Body thread-like, rounded dorsally, flattened ventrally, widest in anterior thoracic chaetigers, and tapering from abdomen to pygidium. Color yellowish white in alcohol. Prostomium short, conical, with short and blunt palpode; nuchal organs not seen, eyespots absent (Fig. 3 A, B). Everted proboscis with small hemispheric papillae (Fig. 3 B). Peristomium weakly bi-annulated and subequal in length with chaetiger 1 (Fig. 3 A, B). Thorax with 11 chaetigers (Fig. 3 A, B). Thoracic segments biannulated, with shallow intra- and intersegmental grooves (Fig. 3 A, B). First chaetiger biramous, with three or four bi-limbated capillaries; chaetigers 2 - 5 with six or seven capillaries per fascicle in both parapodia; chaetigers 6 - 11 with six or seven long-shafted hooded hooks per fascicle (Fig. 3 A, B, F); thoracic hooks with indistinct node on shaft and at least 10 small teeth in three rows above the main fang (Fig. 3 F). Notopodia located in dorso-laterally, dorsally located in last few thoracic segments; neuropodia located in lateral positions (Fig. 3 A, B). Lateral organs present between both parapodia of all thoracic chaetigers, nearer to notopodia in chaetigers three to 11 (Fig. 3 B). Genital pores present in intersegmental furrows between chaetigers 5 - 6, 6 - 7, 7 - 8, 8 - 9, 9 - 10, and 10 - 11; sometimes indistinct between chaetigers 5 - 6 (Fig. 3 B). Transition between thorax and abdomen distinguished by changes in chaetation and shape of segment (Fig. 3 A, B); abdominal segments multi-annulated, with short-shafted hooded hooks in posterior part of segment; thoracic chaetigers usually bi-annulated, with long-shafted hooded hooks in center of segment; last thoracic chaetiger usually shorter than first abdominal chaetiger (Fig. 3 A, B). Abdominal parapodial lobes well separated from each other, located in posterior end of each segment (Fig. 3 A-C). Abdominal notopodia separated, mid-dorsal on anterior few segments, becoming dorsolateral in following abdominal region, with five or six hooded hooks per fascicle, not protruded in anterior abdominal region, and very weakly protruded above epidermis in mid-posterior abdomen; not extended over further segment (Figs 3 A-D, 5 D). Abdominal neuropodia separated, not protruded, with six to eight hooded hooks per fascicle; neuropodial lobes less developed than notopodial lobes (Figs 3 A-C, 5 D). Hooded hooks with main fang extending slightly beyond hoods. Abdominal hooks with distinct node on shaft and four rows of small teeth above main fang; three teeth in basal row, three in second row, four in third row, and two in superior row (Figs 3 E, G, 5 C). Pygidium with digitate anal cirrus (Figs 3 D, 5 D).	en	Jeong, Man-Ki, Soh, Ho Young, Suh, Hae-Lip (2019): Three new species of Heteromastus (Annelida, Capitellidae) from Korean waters, with genetic evidence based on two gene markers. ZooKeys 869: 1-18, DOI: http://dx.doi.org/10.3897/zookeys.869.34380, URL: http://dx.doi.org/10.3897/zookeys.869.34380
F1F81C8F06275EBB8634327E44E29C2A.taxon	etymology	Etymology. The new species is named for its limited distribution in Gusipo, Korea.	en	Jeong, Man-Ki, Soh, Ho Young, Suh, Hae-Lip (2019): Three new species of Heteromastus (Annelida, Capitellidae) from Korean waters, with genetic evidence based on two gene markers. ZooKeys 869: 1-18, DOI: http://dx.doi.org/10.3897/zookeys.869.34380, URL: http://dx.doi.org/10.3897/zookeys.869.34380
F1F81C8F06275EBB8634327E44E29C2A.taxon	distribution	Distribution. Intertidal area (0 - 1 m) near Gusipo, Korea.	en	Jeong, Man-Ki, Soh, Ho Young, Suh, Hae-Lip (2019): Three new species of Heteromastus (Annelida, Capitellidae) from Korean waters, with genetic evidence based on two gene markers. ZooKeys 869: 1-18, DOI: http://dx.doi.org/10.3897/zookeys.869.34380, URL: http://dx.doi.org/10.3897/zookeys.869.34380
F0A1402D37865C809ED18E80FBC2D1E2.taxon	materials_examined	Material examined. Holotype: MABIKNA 00155565, sex uncertain, Muan, 35 ° 6.270 ' N, 126 ° 20.093 ' E, intertidal, tidal mud-flat, 1 m depth, November 2017, coll. Man-Ki Jeong. Paratypes (2 specimens): MABIKNA 00155566, sex uncertain, Anheung, 36 ° 40.740 ' N, 126 ° 9.121 ' E, intertidal, muddy sand beach, 1 m depth, April 2014, coll. Man-Ki Jeong; MABIK NA 00155567, sex uncertain, Gwangyang, 34 ° 55.940 ' N, 127 ° 36.252 ' E, intertidal, tidal mud-flat, 1 m depth, November 2017, coll. Man-Ki Jeong.	en	Jeong, Man-Ki, Soh, Ho Young, Suh, Hae-Lip (2019): Three new species of Heteromastus (Annelida, Capitellidae) from Korean waters, with genetic evidence based on two gene markers. ZooKeys 869: 1-18, DOI: http://dx.doi.org/10.3897/zookeys.869.34380, URL: http://dx.doi.org/10.3897/zookeys.869.34380
F0A1402D37865C809ED18E80FBC2D1E2.taxon	materials_examined	Additional material examined. MABIKNA 00155568, sex uncertain, Seochun, 36 ° 0.95 ' N, 126 ° 39.79 ' E, intertidal, tidal mud-flat, 1 m depth, May 2015, coll. Man-Ki Jeong. Additional seven specimens from type locality on SEM stub.	en	Jeong, Man-Ki, Soh, Ho Young, Suh, Hae-Lip (2019): Three new species of Heteromastus (Annelida, Capitellidae) from Korean waters, with genetic evidence based on two gene markers. ZooKeys 869: 1-18, DOI: http://dx.doi.org/10.3897/zookeys.869.34380, URL: http://dx.doi.org/10.3897/zookeys.869.34380
F0A1402D37865C809ED18E80FBC2D1E2.taxon	diagnosis	Diagnosis. Abdominal hooks with three rows of teeth; two teeth in basal row, three in second row, and four in superior row. Genital pores present in intersegmental furrows between chaetigers 7 - 8, 8 - 9, 9 - 10, and 10 - 11. Posteriorly extended and rounded thin parapodial lobes present on posterior abdominal segments.	en	Jeong, Man-Ki, Soh, Ho Young, Suh, Hae-Lip (2019): Three new species of Heteromastus (Annelida, Capitellidae) from Korean waters, with genetic evidence based on two gene markers. ZooKeys 869: 1-18, DOI: http://dx.doi.org/10.3897/zookeys.869.34380, URL: http://dx.doi.org/10.3897/zookeys.869.34380
F0A1402D37865C809ED18E80FBC2D1E2.taxon	description	Description. Holotype entire, about 28 mm long, 0.5 mm wide for 115 chaetigers. Paratypes range from 36 - 51 mm in length, 0.6 mm width for 89 - 95 chaetigers. Body thread-like, rounded dorsally, flattened ventrally, widest in anterior thoracic chaetigers, and tapering from abdomen to pygidium. Color whitish yellow in alcohol. Prostomium conical, with slender and relatively long palpode; nuchal organs not seen, eyespots usually not observed in preserved specimen (Fig. 4 A), sub-epidermal eyespots observed in few preserved specimens from Anheung of Korea (Fig. 4 B). Everted proboscis with numerous small papillae (Fig. 4 A, B). Peristomium uniannulated and slightly longer than chaetiger 1 (Fig. 4 A, B). Thorax with 11 chaetigers (Fig. 4 A, B). Thoracic segments biannulated, with shallow intra- and intersegmental grooves (Fig. 2 A, B). Anterior five thoracic segments slightly expanded (Fig. 4 A). First chaetiger biramous, with three or four bi-limbated capillaries; chaetigers 2 - 5 with five to eight capillaries per fascicle in both noto- and neuropodia; chaetigers 6 - 11 with six to 10 long-shafted hooded hooks per fascicle (Fig. 4 A, B, F); thoracic hooks with indistinct node on shaft and at least eight small teeth in three or four rows above the main fang (Fig. 4 F). Notopodia located in dorso-laterally, dorsally located in last few thoracic segments; neuropodia located in lateral positions (Fig. 4 A, B). Lateral organs present between noto- and neuropodia of all thoracic chaetigers, nearer to notopodia in chaetigers 5 - 11 (Fig. 4 A). Genital pores present in intersegmental furrows of between chaetigers 7 - 8, 8 - 9, 9 - 10, and 10 - 11 (Fig. 4 A). Transition between thorax and abdomen distinguished by changes in shape of chaetae and segment (Fig. 4 A); anterior abdominal segments multi-annulated, gradually longer posteriorly, with short-shafted hooded hooks placed posteriorly in segment; posterior thoracic chaetigers bi- or tri-anullated, with long-shafted hooded hooks in central part of segment; last thoracic chaetiger smaller than first abdominal chaetiger (Fig. 4 A). Abdominal parapodial lobes located in posterior end of each segment, well separated from each other, and gradually developed posteriorly (Fig. 4 C, D). Abdominal notopodia separated, middorsal on anterior few segments, becoming dorsolateral in following abdominal region, with 5 or 6 short-shafted hooded hooks per fascicle, having posteriorly extended and rounded thin lobes from chaetiger 70 - 80 to end of body; expanded notopodial lobes overlap dorso-anterior part of further segment (Figs 4 C, D, 5 F). Abdominal neuropodia well separated, with 10 - 12 short-shafted hooded hooks per fascicle, having slightly protruded lobes in posterior abdomen; neuropodial lobes less developed than notopodial lobes (Figs 4 C, D, 5 F). Hooded hooks with main fang extending slightly beyond hoods. Abdominal hooks with distinct node on shaft and three rows of small teeth above main fang; two teeth in basal row, three in second row, and four in superior row (Figs 4 E, G, 5 E). Pygidium with digitate anal cirrus (Fig. 4 D).	en	Jeong, Man-Ki, Soh, Ho Young, Suh, Hae-Lip (2019): Three new species of Heteromastus (Annelida, Capitellidae) from Korean waters, with genetic evidence based on two gene markers. ZooKeys 869: 1-18, DOI: http://dx.doi.org/10.3897/zookeys.869.34380, URL: http://dx.doi.org/10.3897/zookeys.869.34380
F0A1402D37865C809ED18E80FBC2D1E2.taxon	etymology	Etymology. The new species is named for its wide distribution in coastal waters of Korea.	en	Jeong, Man-Ki, Soh, Ho Young, Suh, Hae-Lip (2019): Three new species of Heteromastus (Annelida, Capitellidae) from Korean waters, with genetic evidence based on two gene markers. ZooKeys 869: 1-18, DOI: http://dx.doi.org/10.3897/zookeys.869.34380, URL: http://dx.doi.org/10.3897/zookeys.869.34380
F0A1402D37865C809ED18E80FBC2D1E2.taxon	distribution	Distribution. Intertidal areas (0 - 1 m) near Korea (Fig. 1).	en	Jeong, Man-Ki, Soh, Ho Young, Suh, Hae-Lip (2019): Three new species of Heteromastus (Annelida, Capitellidae) from Korean waters, with genetic evidence based on two gene markers. ZooKeys 869: 1-18, DOI: http://dx.doi.org/10.3897/zookeys.869.34380, URL: http://dx.doi.org/10.3897/zookeys.869.34380
C9B63C59DB6A57749F75A5A34E5E384C.taxon	materials_examined	Material examined. Holotype: MABIKNA 00155558, sex uncertain, Cheongsando, 34 ° 1.662 ' N, 127 ° 4.272 ' E, subtidal, sandy mud bottom, 34 m depth, March 2016, coll. Man-Ki Jeong. Paratypes (two specimens): MABIKNA 00155560, Yeosu, 34 ° 41.569 ' N, 127 ° 51.848 ' E, subtidal, sandy mud bottom, 15 m depth, June 2018; MABIK NA 00155559, Jejudo, 33 ° 16.699 ' N, 127 ° 16.230 ' E, subtidal, sandy mud bottom, 54 m depth, April 2018. Additional 6 specimens from type locality on SEM stub.	en	Jeong, Man-Ki, Soh, Ho Young, Suh, Hae-Lip (2019): Three new species of Heteromastus (Annelida, Capitellidae) from Korean waters, with genetic evidence based on two gene markers. ZooKeys 869: 1-18, DOI: http://dx.doi.org/10.3897/zookeys.869.34380, URL: http://dx.doi.org/10.3897/zookeys.869.34380
C9B63C59DB6A57749F75A5A34E5E384C.taxon	diagnosis	Diagnosis. Abdominal hooks with four rows of teeth, three teeth in basal row, three in second and third row, and four to six in superior row. Genital pores present in intersegmental furrows between chaetigers 7 - 8, 8 - 9, 9 - 10, and 10 - 11. Hemispheric notopodial lobes present on posterior abdominal segments.	en	Jeong, Man-Ki, Soh, Ho Young, Suh, Hae-Lip (2019): Three new species of Heteromastus (Annelida, Capitellidae) from Korean waters, with genetic evidence based on two gene markers. ZooKeys 869: 1-18, DOI: http://dx.doi.org/10.3897/zookeys.869.34380, URL: http://dx.doi.org/10.3897/zookeys.869.34380
C9B63C59DB6A57749F75A5A34E5E384C.taxon	description	Description. Holotype entire, about 60 mm long, 0.9 mm wide for 98 chaetigers (terminal part missing). Paratypes range from 19 - 41 mm in length, 0.5 - 0.8 mm width for 41 - 95 chaetigers. Body thread-like, rounded dorsally, flattened ventrally, widest in anterior thoracic chaetigers, and tapering from abdomen to pygidium. Color brownish yellow in alcohol. Prostomium conical, with short and hemispherical palpode; nuchal organs not seen, eyespots absent (Fig. 2 A, B). Everted proboscis with numerous small papillae (Fig. 2 A). Peristomium uni-annulated and slightly longer than first thoracic chaetiger (Fig. 2 A, B). Thorax with 11 chaetigers (Fig. 2 A, B). Thoracic segments biannulated, with shallow intra- and intersegmental grooves (Fig. 2 A, B). Anterior five thoracic segments slightly expanded (Fig. 2 A, B). First chaetiger biramous, with three or four bi-limbated capillaries; chaetigers 2 - 5 with six to 14 capillaries per fascicle in both parapodia; chaetigers 6 - 11 with five to 12 long-shafted hooded hooks per fascicle (Fig. 2 A, B, F); thoracic hooks with indistinct node on shaft and at least six teeth in three rows above the main fang (Fig. 2 F). Notopodia located dorso-laterally, dorsally located in last few thoracic segments; neuropodia located in lateral positions (Fig. 2 A, B). Lateral organs present between noto- and neuropodia of all thoracic chaetigers, nearer to notopodia in chaetigers 5 - 11; sometimes indistinct on first thoracic chaetigers (Fig. 2 A). Genital pores present in intersegmental furrows of between chaetigers 7 - 8, 8 - 9, 9 - 10, and 10 - 11 (Fig. 2 A). Transition between thorax and abdomen distinguished by changes in ultrastructure of chaetae and shape of segment (Fig. 2 A, B); abdominal segments multi-annulated, gradually longer posteriorly, with short-shafted hooded hooks in posterior parapodial lobes; thoracic chaetigers usually bi-annulated, wider than long, with long-shafted hooded hooks in center of segment (Fig. 2 A, B). Abdominal parapodial lobes located in posterior end of each segment, well separated from each other, and gradually developed posteriorly (Fig. 2 A-D). Abdominal notopodia separated, mid-dorsal on anterior few segments, becoming dorsolateral in following abdominal region, with six to eight hooded hooks per fascicle, having dorso-posteriorly protruded and hemispheric lobes from chaetiger 90 to end of body (Figs 2 A-D, 5 B). Abdominal neuropodia well separated, with 10 - 12 hooded hooks per fascicle, having slightly protruded lobes in posterior abdomen; neuropodial lobes less developed than notopodial lobes (Figs 2 C, D, 5 B). Hooded hooks with main fang extending slightly beyond hoods. Abdominal hooks with distinct node on shaft and four rows of small teeth above main fang; three teeth in basal row, three in second and third row, and four to six in superior row (Figs 2 E, G, 5 A). Pygidium with digitate anal cirrus (Figs 2 D, 5 B).	en	Jeong, Man-Ki, Soh, Ho Young, Suh, Hae-Lip (2019): Three new species of Heteromastus (Annelida, Capitellidae) from Korean waters, with genetic evidence based on two gene markers. ZooKeys 869: 1-18, DOI: http://dx.doi.org/10.3897/zookeys.869.34380, URL: http://dx.doi.org/10.3897/zookeys.869.34380
C9B63C59DB6A57749F75A5A34E5E384C.taxon	etymology	Etymology. The species is named for its wide distribution in Namhae (= Korean name of southern sea of Korea).	en	Jeong, Man-Ki, Soh, Ho Young, Suh, Hae-Lip (2019): Three new species of Heteromastus (Annelida, Capitellidae) from Korean waters, with genetic evidence based on two gene markers. ZooKeys 869: 1-18, DOI: http://dx.doi.org/10.3897/zookeys.869.34380, URL: http://dx.doi.org/10.3897/zookeys.869.34380
C9B63C59DB6A57749F75A5A34E5E384C.taxon	distribution	Distribution. Subtidal areas (15 - 54 m) near southern part of Korea (Fig. 1).	en	Jeong, Man-Ki, Soh, Ho Young, Suh, Hae-Lip (2019): Three new species of Heteromastus (Annelida, Capitellidae) from Korean waters, with genetic evidence based on two gene markers. ZooKeys 869: 1-18, DOI: http://dx.doi.org/10.3897/zookeys.869.34380, URL: http://dx.doi.org/10.3897/zookeys.869.34380
