Research Article |
Corresponding author: Il-Hoi Kim ( ihkim@gwnu.ac.kr ) Academic editor: Danielle Defaye
© 2022 Jimin Lee, Cheon Young Chang, Il-Hoi Kim.
This is an open access article distributed under the terms of the Creative Commons Attribution License (CC BY 4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Citation:
Lee J, Chang CY, Kim I-H (2022) Symbiotic copepods (Cyclopoida and Siphonostomatoida) collected by light trap from Korea. ZooKeys 1115: 1-71. https://doi.org/10.3897/zookeys.1115.83266
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Thirty-nine species of symbiotic copepods, comprising 24 species of poecilostome Cyclopoida and 15 species of Siphonostomatoida, are reported from Korean waters, which were collected using underwater light traps at 33 collection sites around the South Korean coast. Ten new species are described: Hemicyclops rapax sp. nov. in the family Clausidiidae; Pontoclausia cochleata sp. nov. and P. pristina sp. nov. in the family Clausiidae; Heteranthessius unisetatus sp. nov. in the family Lichomolgidae; Pusanomyicola sensitivus gen. nov., sp. nov. in the family Myicolidae; Polyankylis bogilensis sp. nov. in the family Polyankyliidae; Pseudanthessius linguifer sp. nov. in the Pseudanthessiidae; Eupolymniphilus foliatus sp. nov. in the family Sabelliphilidae; and Acontiophorus estivalis sp. nov. and Thermocheres pacificus sp. nov. in the family Asterocheridae. Supplementary descriptions or notes for other species are provided as appropriate.
Copepoda, Crustacea, new genus, new species, taxonomy
Light traps are useful tools for collecting marine animals. According to
Crustaceans are the most abundant marine animals that are caught in light traps (
Recently copepods caught in light traps have been recorded frequently in Korea (
Copepod specimens in this study were collected using underwater light traps at 33 collection sites (Fig.
Sites | Localities | Coordinates |
---|---|---|
1 | Sadong, Ulleung I. | 37°27'35.7"N, 130°52'34.6"E |
2 | Namyang, Ulleung I. | 37°28'01.3"N, 130°50'01.4"E |
3 | Geojin, Goseong | 38°26'38"N, 128°27'27"E |
4 | Ban-am, Goseong | 38°25'30"N, 128°27'47"E |
5 | Imwon, Samcheok | 37°13'44"N, 129°20'45"E |
6 | Jukbyeon, Uljin | 37°03'22"N, 129°25'22"E |
7 | Gampo, Gyeongju | 35°48'29"N, 129°30'19"E |
8 | Eupcheon, Gyeongju | 35°41'32.6"N, 129°28'30.4"E |
9 | Bangeojin, Ulsan | 35°29'03.9"N, 129°25'44.5"E |
10 | Haeundae, Pusan | 35°09'30"N, 129°10'14"E |
11 | Yeongdo, Pusan | 35°04'31.0"N, 129°05'08.7"E |
12 | Near Pusan Fish Market | 35°05'46"N, 129°01'51"E |
13 | Minam-ri, Tongyeong | 34°46'02.9"N, 128°24'21.1"E |
14 | Junghwa-ri, Tongyeong | 34°47'25.1"N, 128°23'17.9"E |
15 | Honghyeon-ri, Namhae I. | 34°45'00.5"N, 127°54'33.9"E |
16 | Deogweol, Namhae I | 34°46'35.3"N, 127°50'57"E |
17 | Geum-oh I. | 34°30'33.1"N, 127°46'10.1"E |
18 | Doryak-ri, Cheongsan I. | 34°10'12"N, 126°51'13"E |
19 | Ul-mool, Sinji I. | 34°19'25.4"N, 126°48'06.7"E |
20 | Myeongsa, Sinji I. | 34°19'25.48"N, 126°48'05.04"E |
21 | Nohwa I. | 34°13'28"N, 126°53'47"E |
22 | Yesong, Bogil I. | 34°08'11"N, 126°33'49"E |
23 | Galdu, Haenam | 34°17'57"N, 126°31'50"E |
24 | Saehwa, Jeju I. | 33°31'45"N, 126°51'25"E |
25 | Geumgap-ri, Chindo I. | 34°23'30.7"N, 126°17'01.1"E |
26 | Chopyeong, Chindo I. | 34°24'46.3"N, 126°20'11.1"E |
27 | Saepo, Chindo I. | 34°25'10.4"N, 126°05'39.0"E |
28 | Gahak, Chindo I. | 34°25'52.7"N, 126°05'51.4"E |
29 | Bojeon, Chindo I. | 34°29'08.5"N, 126°10'18.5"E |
30 | Gosan, Palgeum I. | 34°47'38"N, 126°10'22"E |
31 | Wido I. | 35°37'04"N, 126°18'15"E |
32 | Sinjin, Taean | 36°40'50"N, 126°08'05"E |
33 | Dumoojin, Baekryeongdo I. | 37°58'31"N, 124°37'10"E |
Order Cyclopoida Burmeister, 1834
One ♀, Site 12, 16 Mar. 2013.
This copepod has been known only from the bivalve Atrina pectinata (Linnaeus, 1767). The copepod is presumed to have escaped from its bivalve host in a fish market aquarium into the adjacent waters of the collection site, where the host cannot dwell due to the water pollution.
Twenty ♀♀, 9 ♂♂, Site 4, 19 Jul. 2016; 2 ♀♀, Site 5, 21 Jul. 2016; 37 ♀♀, 2 ♂♂, Site 7, 21 Jun. 2019; 7 ♀♀, 3 ♂♂, Site 8, 18 May 2015; 17♀♀, 2 ♂♂, Site 9, 17 May 2015; 8 ♀♀, 2 ♂♂, Site 11, 03 Jun. 2019; 1♀, 1 ♂, Site 11, 07 Jul. 2020; 9 ♀♀, Site 11, 16 Apr. 2014; 10 ♀♀, Site 11, 20 Aug. 2020; 11 ♀♀, Site 12, 16 Mar. 2013; 1♀, 1 ♂, Site 13, 03 Jul. 2020; 9 ♀♀, 1 ♂, Site 14, 03 Jul. 2020; 1 ♀, Site 15, 04 Jul. 2020; 6 ♀♀, Site 16, 04 Jul. 2020; 5 ♀♀, Site 17, 13 May 2015; 24 ♀♀, 4 ♂♂, Site 18, 27 Apr. 2017; 2 ♀♀, Site 19, 05 Jun. 2020; 6 ♀♀, 2 ♂♂, Site 21, 26 May 2017; 62 ♀♀, 13 ♂♂, Site 22, 26 Apr. 2021; 30 ♀♀, 10 ♂♂, Site 22, 31 May 2021; 11 ♀♀, 3 ♂♂, Site 23, 24 Apr. 2021; 3 ♀♀, 1 ♂, Site 26, 06 Jul. 2016; 10 ♀♀, 1 ♂, Site 32, 24 May 2020; 4 ♀♀, 2 ♂♂, Site 33, 11 Aug. 2020.
Body (Fig.
Mandible (Fig.
Leg 4 with three spines and five setae on third exopodal segment. Leg 5 exopod 2.1 × longer than wide.
Male. Body form as in female. Body length of measured specimen 1.20 mm.
Anthessius graciliunguis Do & Kajihara, 1984 was described originally as an associate of the mussel Mytilus galloprovincialis Lamarck, 1819 from Japan (
The diagnostic morphological features of the female of A. graciliunguis are as follows: (1) the caudal ramus is ~ 3.5 × longer than wide, (2) the terminal segment of antenna is 3.0 × longer than wide; (3) the convex outer margin of the distal lash of maxilla is ornamented with five spines; (4) the third exopodal segment of leg 4 is armed with three spines and five setae; and (5) the exopod of leg 5 is 2.1 × longer than wide. The first (1) and last (5) may be the simple combination of features sufficient to differentiate A. graciliunguis from its congeners.
One ♂, Site 4, 19 Jul. 2016; 1 ♀, Site 12, 16 Mar. 2013; 1 ♀, Site 33, 11 Aug. 2020.
In Korea, Conchyliurus quintus is widely distributed along the entire coast. It has a low host specificity, inhabiting 12 species of bivalves in Korea (
Two ♀♀, Site 11, 16 Apr. 2014; 20 ♀♀, 17 ♂♂, Site 22, 31 May 2021; 1 ♀, Site 24, 16 May 2019.
This species is easily identifiable due to the characteristic genital double-somite of the female, which has a deep lateral constriction between the anterior third and posterior two-thirds and a pointed process on each lateral margin. The host of this copepod is still unknown.
One ♀, Site 11, 16 Apr. 2014; 1 ♂, Site 20, 05 Jun. 2020; 1 ♀, 7 ♂♂, Site 22, 31 May 2021; 1 ♀, Site 23, 24 Apr. 2021; 1 ♀, 2 ♂♂, Site 27, 09 Jul. 2016.
Body form as in female. Body length 1.30 mm. Urosome six-segmented. Genital somite wider than long. Caudal ramus 3.03 × longer than wide (115 × 38 μm). Antennule with same armature formula as in female. Antenna, mandible, maxillule the same as those of female. Basis (distal segment) of maxilla terminating in stout claw. Maxilliped four-segmented; first segment (syncoxa) with single large spinulose seta subdistally on inner margin; second segment (basis) broadened proximally, markedly tapering distally, armed with two unequal setae (one spinulose and one minute), and ornamented with three longitudinal rows of denticles along inner margin; small third segment (first endopodal segment) unarmed; terminal segment forming long, curved claw bearing two setae proximally.
Leg 1 different from that of female in absence of inner distal spine on basis. Legs 2–4 as in female. Leg 5 consisting of single dorsolateral seta on fifth pedigerous somite and exopod; protopod completely fused with somite. Leg 6 represented by one spine on posterolateral corner of genital operculum.
Holotype ♀ (MABIK CR00250118) and paratype ♀ (MABIK CR00250119) preserved in 90% alcohol, Site 22 (Yesong, Bogil Island, south coast, 34°08'11"N, 126°33'48"E), 31 May 2021, leg. J. Lee; paratype ♂ (MABIK CR00250123, figured) dissected and mounted on a slide, Site 22, 26 April 2021, leg. J. Lee and C. Y. Chang; 1 ♀ preserved in 90% alcohol and 1 ♀ (figured) dissected and mounted on a slide, Site 11 (Yeongdo, Pusan, 35°04'31.0"N, 129°05'08.7"E), 07 Jul. 2020, leg. J. G. Kim.
Female. Body (Fig.
Hemicyclops rapax sp. nov., female A habitus, dorsal B urosome, dorsal (arrowhead indicates a small denticle on lateral margin of genital double-somite) C anal somite and caudal rami, dorsal D antennule E antenna F mandible G paragnath H maxillule. Scale bars: 0.2 mm (A); 0.1 mm (B); 0.05 mm (C, D); 0.02 mm (E–H).
Rostrum small, with convex posterior margin. Antennule (Fig.
Labrum (Fig.
Legs 1–4 biramous, with three-segmented rami (Fig.
Coxa | Basis | Exopod | Endopod | |
Leg 1 | 0-1 | 1-I | I-0; I-1; II, 6 | 0-1; 0-1; I, 5 |
Legs 2 & 3 | 0-1 | 1-0 | I-0; I-1; II, 7 | 0-1; 0-2; I, II, 3 |
Leg 4 | 0-1 | 1-0 | I-0; I-1; II, 6 | 0-1; 0-2; I, II, 2 |
Leg 5 (Fig.
Male. Body (Fig.
Rostrum as in female. Antennule different from that of female in having one additional seta at proximal anterior margin of fourth segment (thus with 4 setae on this segment). Antenna, labrum, mandible, paragnath, maxillule as in female. Maxilla different from that of female; basis armed with two spines and one seta and terminating in stout, claw-like process bearing spinules on outer margin and granule-like papillae on distal region (Fig.
Leg 1 different from that of female in absence of inner distal element on basis (Fig.
The specific name rapax is derived from the Latin rapa (grasping), alluding to the grasping form of the female maxilliped.
Hemicyclops rapax sp. nov. is characterized by its peculiar female maxilliped, in which the terminal segment is transformed to a large hook, as in the males of existing species. This form of female maxilliped is very unusual for the genus, since the terminal segment (second endopodal segment) of the female maxilliped in other species of the genus generally terminates in a spiniform process (or a spine). The only other example of this peculiar female maxilliped in Hemicyclops is that of H. cylindraceus (Pelseneer, 1929), as illustrated by
Hemicyclops rapax sp. nov. may be differentiated from its congeners in other ways. In eight species in Hemicyclops the caudal ramus is short, less than 1.5 × longer than wide in the female, as in H. rapax sp. nov. In five of these eight species (H. apiculus Humes, 1995, H. australis Nicholls, 1944, H. intermedius Ummerkutty, 1962, H. parapiculus Kim & Hong, 2014, and H. vicinalis Humes, 1995), the genital double-somite of the female is distinctly longer than wide (more than 1.2 × longer than wide); in H. tamilensis (Thompson & T. Scott, 1903) the urosome of the female is six-segmented and the exopod of leg 5 is elongated; in H. saxatilis Ho & Kim, 1992 the basis of male leg 1 bears an inner distal spine, the first segment of the male maxilliped is armed with two (rather than one) setae, and the maxilla is not sexually dimorphic. In the remaining species, H. leggii (Thompson & T. Scott, 1903) described based on the male, the third endopodal segment is armed with five armature elements (I, 4, rather than I, 5), the basis of male leg 1 is armed with an inner distal spine, and the first segment of male maxilliped is armed with two setae. These differences are considered sufficient to distinguish the new species from these eight congeners.
Two ♀♀, Site 11, 20 Aug. 2020; 1 ♀, Site 12, 16 Mar. 2013; 2 ♀♀, 1 ♂, Site 15, 04 Jul. 2020; 1 ♀, Site 20, 05 Jun. 2020; 2 ♀♀, 8 ♂♂, Site 26, 06 Jul. 2016; 1 ♂, Site 33, 11 Aug. 2020.
Due to the close relatedness of this species to H. gomsoensis Ho & Kim, 1992,
One ♀, Site 1, 28 Jun. 2021; 1 ♀, Site 22, 31 May 2021.
This is the second record of Hersiliodes exiguus which was originally recorded as an associate of the clam Ruditapes philippinarum (A. Adams & Reeve, 1850) inhabiting a brackish lagoon on the east coast of Korea (
Holotype ♀ (MABIK CR00250124) dissected and mounted on a slide, Site 22 (Yesong, Bogil Island, south coast, 34°08'11"N, 126°33'49"E), 26 Apr. 2021, leg. J. Lee and C. Y. Chang; Paratype ♂ (MABIK CR00250125) dissected and mounted on a slide, Site 27 (Sepo, Chindo Island, southwest coast, 34°25'10.4"N, 126°05'39.0"E), 09 Jul. 2016, leg. J. Lee and C. Y. Chang.
Female. Body (Fig.
Rostrum represented by spatulate anterior prominence of cephalothorax (Fig.
Labrum (Fig.
Legs 1–4 (Fig.
Coxa | Basis | Exopod | Endopod | |
Leg 1 | 0-0 | 1-I | I-0; I-1; III, I, 4 | 0-1; 0-1; I, 2, 2 |
Leg 2 | 0-0 | 1-0 | I-0; I-1; III, I, 5 | 0-1; 0-2; II, I, 3 |
Leg 3 | 0-0 | 1-0 | I-0; I-1; II, I, 5 | 0-1; 0-2; II, I, 3 |
Leg 4 | 0-0 | 1-0 | I-0; I-1; II, I, 5 | 0-1; 0-2; II, I, 2 |
Leg 5 (Fig.
Male. Body form (Fig.
Rostrum as in female. Antennule and antenna segmented and armed as in female. Labrum, mandible, maxillule, and maxilla also as in female. Maxilliped (Fig.
Leg 1 (Fig.
The specific name cochleata is derived from the Latin cochl (a spoon), alluding to the spoon-like mandible of the new species.
With the three-segmented rami of legs 1–4, the inner distal spine on the basis of leg 1, and the laterally positioned leg 5, the new species apparently belongs to the genus Pontoclausia which contains five known species (
Holotype ♂ (MABIK CR00250126) dissected and mounted on a slide, Site 1 (Sadong, Ulleung Island, 37°27'35.7"N, 130°52'34.6"E), 28 Jun. 2021, leg. J. G. Kim.
Male. Body (Fig.
Rostrum (Fig.
Mouthparts small, except large maxilliped. Labrum (Fig.
Legs 1–4 (Fig.
Coxa | Basis | Exopod | Endopod | |
Leg 1 | 0-0 | 1-I | I-0; I-1; III, I, 3 | 0-1; 0, II, 1 |
Leg 2 | 0-0 | 1-0 | I-0; I-1; II, I, 4 | 0-1; 0-1; II, I, 3 |
Leg 3 | 0-1 | 1-0 | I-0; I-1; II, I, 4 | 0-1; 0-1; II, I, 3 |
Leg 4 | 0-0 | 1-0 | I-0; I-1; III, I, 2 | 0-1; 0-1; II, I, 2 |
Leg 5 (Fig.
Female. Unknown.
The specific name of the new species is derived from the Latin pristin (primitive), referring to the primitive condition of its antenna and mouthparts.
Although only a single male specimen is available for the description of Pontoclausia pristina sp. nov., it is distinctively characterized by its primitive antenna which is four-segmented with a full armature and by primitive, Hemicyclops-type mandible, maxillule and maxilla. The taxonomic position of the new species appears to be intermediate between the genera Hemicyclops and Pontoclausia of the Clausiidae. In the new species (1) the body is slender, harpacticiform (Pontoclausia-type feature); (2) the antennule is six-segmented (Pontoclausia-type); (3) the antenna is four-segmented, with 1, 1, 4, and 7 armature elements respectively on the first to fourth segments (Hemicyclops-type); (4) the mandible bears three or four distal armature elements (Hemicyclops-type); (5) the maxillule is distally bilobed with a total of eight setae (Hemicyclops-type); (6) the maxilla is two-segmented, with two distinct setae on the proximal segment and three armature elements plus one spiniform process on the distal segment (Hemicyclops-type); (7) the endopod of male leg 1 is two-segmented (Pontoclausia-type); (8) most of swimming legs lack the inner coxal seta (Pontoclausia-type); (9) the second endopodal segment of legs 2–4 bears only a single inner seta (Pontoclausia-type); and (10) the setation of the third exopodal and endopodal segments of most swimming legs is reduced (Pontoclausia-type). We consider that the two-segmented condition of the endopod of male leg 2 (above character state 7), which is a consistent, typical feature of Pontoclausia, is the most important taxonomic feature for determining the familial position of the new species; therefore, we place it within the Clausiidae. Pontoclausia pristina sp. nov. is distinguished from its congeners and other species in the family by the above Hemicyclops-type features.
One ♀, Site 15, 04 Jul. 2020.
One ♀, Site 12, 16 Mar. 2013.
Herrmannella dentata was originally described as an associate of the bivalves Mya japonica Jay, 1857 and Gari kazusensis (Yokoyama, 1922) in the Peter the Great Bay, Russia (
One ♂, Site 11, 03 Jun. 2019; 1 ♀, 4 ♂♂, Site 12, 16 Mar. 2013; 1 ♂, Site 17, 13 May 2015.
This copepod species had been found only in the bivalve Saxidomus purpurata (Sowerby, 1852).
One ♀, 3 ♂♂, Site 33, 11 Aug. 2020.
Holotype ♂ (MABIK CR00250127) dissected and mounted on a slide, Site 6 (Jukbyeon Port, Uljin, 36°49'26.4"N, 129°26'52.2"E), 21 Sep. 2020, leg. J. Lee and J. G. Kim.
Male. Body (Fig.
Rostrum (Fig.
Labrum (Fig.
Legs 1–4 biramous; outer seta on basis small; spines on rami with densely serrate margins. Legs 1–3 (Fig.
Coxa | Basis | Exopod | Endopod | |
Leg 1 | 0-1 | 1-0 | I-0; I-1; III, I, 4 | 0-1; 0-2; I, I, 4 |
Leg 2 | 0-1 | 1-0 | I-0; I-1; III, I, 5 | 0-1; 0-2; I, II, 3 |
Leg 3 | 0-1 | 1-0 | I-0; I-1; III, I, 5 | 0-1; 0-2; I, II, 2 |
Leg 4 | 0-1 | 1-0 | I-0; I-1; III, I, 5 | 0, 0, 1 (or 0, 0, 0) |
Leg 5 (Fig.
Female. Unknown.
The specific name of the new species is derived from Latin words, referring to the presence of a single seta on the maxillule and maxilla.
The genus Heteranthessius consists of four known species: H. dubius (T. Scott, 1903) from an unknown host in Scotland (T.
Eight ♀♀, 2 ♂♂, Site 12, 16 Mar. 2013; 1 ♀, Site 23, 24 Apr. 2021.
Modiolicola bifidus has a very low host specificity and is distributed all around the Korean.
Male. Body narrow, cyclopiform, clearly segmented. Prosome consisting of cephalosome and four pedigerous somites. Urosome six-segmented. Caudal ramus with six setae, Antennule seven-segmented, heavily armed with setae and aesthetascs; first and second segments with multiple aesthetascs. Antenna three-segmented, consisting of coxobasis and two-segmented endopod, and terminated in single, strong claw. Labrum broader than long, with short posterolateral lobes. Mandible distally armed with three denticle-like elements, innermost one articulate at base. Maxillule as lobe tipped with two setae. Maxilla as lobe tipped with single seta. Maxilliped four-segmented; armature formula 0, 2, 0, and 1; terminal claw reduced, rudimentary. Legs 1–4 biramous, with three-segmented rami. Coxa of all swimming legs with small inner seta. Leg 1 lacking inner distal armature element on basis. Second endopodal segment of legs 2–4 armed with two inner setae. Third endopodal segment of legs 2 and 3 armed with three spines plus three setae (formula I, II, 3). Third exopodal segment of legs 3 and 4 armed with three spines plus five setae (formula II, I, 5). Leg 5 consisting of protopod and exopod; protopod well-defined from somite; exopod armed with three setae. Leg 6 represented by three setae on genital operculum.
Pusanomyicola sensitivus gen. nov., sp. nov. (original designation).
The generic name is the combination of “Pusan”, the type locality of the type species, and Myicola, the type genus of the family. Gender masculine.
It is notable that one typical feature of the Anthessiidae is in the antennule. In poecilostome cyclopods, the armature of three terminal segments of the antennule (4+aesthetasc, 2+aesthetasc, and 7+aesthetasc) is generally determined as early as the copepodid II stage, and this armature formula remains unchanged throughout subsequent developmental stages. However, the position of the aesthetasc on the antepenultimate segment (the segment of 4+aesthetasc) differs between the Anthessiidae and other poecilostome families, since the aesthetasc in the Anthessiidae is inserted at the distal corner, accompanied with anterodistal seta (Fig.
Pusanomyicola gen. nov. is more similar to Conchocheres than to any other known genera of the Myicolidae; their shared features are the unsegmented maxilla bearing a single distal element, the absence of the inner distal element on the basis of leg 1, and the possession of only three setae on the exopod of leg 5. Nevertheless, Pusanomyicola gen. nov. cannot be considered congeneric with Conchocheres due to their significant differences on the generic level, as follows: (1) the male urosome is five-segmented in Conchocheres malleolatus Sars, 1918, the type and only species of Conchocheres, while it is six-segmented in Pusanomyicola sensitivus gen. nov., sp. nov.; (2) the male antennule of C. malleolatus bears five aesthetascs as illustrated by
We place Pusanomyicola gen. nov. in the Myicolidae on the basis of its myicolid form of antenna bearing a single robust terminal claw and a truncate inner distal seta on the terminal segment, the presence of a group of spinules on the labrum, maxilla and genital operculum, and the myicolid form mandible. We confirm that Conchocheres, which shares important character states with Pusanomyicola gen. nov., is placed in the Myicolidae, as well.
Holotype ♂ (MABIK CR00250128) dissected and mounted on a slide, Site 11 (Yeongdo, Pusan, 35°04'31.0"N, 129° 05'08.7"E), 07 Jul. 2020, leg. J. G. Kim.
Male. Body (Fig.
Rostrum not developed. Antennule (Fig.
Labrum (Fig.
Legs 1–4 (Fig.
Coxa | Basis | Exopod | Endopod | |
Leg 1 | 0-1 | 1-0 | I-0; I-1; III, I, 4 | 0-1; 0-1; I, 2, 3 |
Leg 2 | 0-1 | 1-0 | I-0; I-1; III, I, 5 | 0-1; 0-2; I, II, 3 |
Leg 3 | 0-1 | 1–0 | I-0; I-1; II, I, 5 | 0-1; 0-2; I, II, 3 |
Leg 4 | 0-1 | 1-0 | I-0; I-1; II, I, 5 | 0-1; 0-2; I, II, 2 |
Leg 5 (Fig.
Female. Unknown.
The specific name sensitivus refers to the presence of the multiple aesthetascs on the male antennule.
One ♀, Site 27, 09 Jul. 2016.
Holotype ♀ (MABIK CR00250129) dissected and mounted on a slide, Site 22 (Yesong, Bogil Island, south coast, 34°08'11"N, 126°33'49"E), 31 May 2021, leg. J. Lee.
Female. Body (Fig.
Rostrum (Fig.
Labrum (Fig.
Leg 1–3 (Fig.
Coxa | Basis | Exopod | Endopod | |
Leg 1 | 0-1 | 1-0 | I-0; I-1; III, 4 | 0-1; I, 1, 5 |
Leg 2 | 0-1 | 1-0 | I-0; I-1; III, 5 | 0-1; III, 4 |
Leg 3 | 0-1 | 1-0 | I-0; I-1; III, 5 | 0-1; III, 3 |
Leg 4 | 0-0 | 1-0 | I-0; II, I, 3 | (lacking) |
Leg 5 (Fig.
Male. Unknown.
The name of the new species is taken from the type locality, Bogil Island.
The genus Polyankylis currently consists of three known species: P. orientalis Ho & Kim, 1997, P. australis Karanovic, 2008, and P. ovilaxa. Polyankylis australis is known from Australia (
Holotype ♀ (MABIK CR00250120) and intact paratypes 3 ♀♀ (MABIK CR00250121) preserved in 90% alcohol, and paratype ♀ dissected and mounted on a slide, Site 22 (Yesong, Bogil Island, south coast, 34°08'11"N, 126°33'49"E), 31 May 2021, leg. J. Lee; ♀ dissected and mounted on a slide, Site 23 (Haenam, south coast, 34°17'57"N, 126°31'50"E), 24 Apr. 2021, leg. J. Lee and C. Y. Chang. Dissected specimens are retained in the collection of I.-H. Kim.
Female. Body (Fig.
Rostrum (Fig.
Labrum (Fig.
Legs 1–4 (Fig.
Coxa | Basis | Exopod | Endopod | |
Leg 1 | 0-1 | 1-0 | I-0; I-1; III, I, 4 | 0-1; 0-1; I, 1, 4 |
Leg 2 | 0-1 | 1-0 | I-0; I-1; III, I, 5 | 0-1; 0-2; I, II, 3 |
Leg 3 | 0-1 | 1-0 | I-0; I-1; III, I, 5 | 0-1; 0-2; I, II, 2 |
Leg 4 | 0-1 | 1-0 | I-0; I-1; II, I, 5 | 0, II, 0 |
Leg 5 (Fig.
Male. Unknown.
The specific name of the new species linguifer is derived from Latins lingu (the tongue) and fer (bear), referring to the presence of the tongue-like dorsolateral processes on the genital double-somite.
The most conspicuous feature of Pseudanthessius linguifer sp. nov. is its elongate caudal rami, which are 10 × longer than wide. Such long caudal rami are exhibited by four congeners: P. concinnus Thompson & Scott, 1903, P. dubius Sars, 1918, P. thorelli (Brady & Robertson, 1875), and P. stenosus Kim & Hong, 2014. All of the other species in the genus have shorter caudal rami, at most 8.5 × longer than wide, as in P. deficiens Stock, Humes & Gooding, 1964 (
One ♀, Site 4, 19 Jul. 2016.
The host of this copepod is the actiniarian Anthopleura anjunae Den Hartog & Vennam, 1993. The previously recorded host name Anthopleura midori Uchida & Muramatsu, 1958 is a junior synonym of A. anjunae (
Five ♀♀, 2 ♂♂, Site 22, 26 Apr. 2021; 5 ♂♂, Site 27, 09 Apr. 2016.
The host of this copepod is still unknown but is probably a polychaete.
Holotype ♀ (MABIK CR00250130) and paratype ♂ dissected and mounted on a slide, and intact paratypes 2 ♂♂ (MABIK CR00250122) preserved in 90% alcohol, Site 2 (Namyang, Ulleung Island, Sea of Japan, 37°28'01.3"N, 130°50'01.4"E), 01 Jul. 2021, leg. J. G. Kim. Dissected paratype (♂) is retained in the collection of I.-H. Kim.
Female. Body (Fig.
Rostrum (Fig.
Labrum (Fig.
Legs 1–4 (Fig.
Coxa | Basis | Exopod | Endopod | |
Leg 1 | 0-1 | 1-0 | I-0; I-1; III, I, 4 | 0-1; 0-1; I, 1, 4 |
Leg 2 | 0-1 | 1-0 | I-0; I-1; III, I, 5 | 0-1; 0-2; I, II, 3 |
Leg 3 | 0-1 | 1-0 | I-0; I-1; III, I, 5 | 0-1; 0-2; I, II, I+2 |
Leg 4 | 0-1 | 1-0 | I-0; I-1; II, I, 5 | 0-1; 0-1; I, II, II |
Leg 5 (Fig.
Male. Body (Fig.
Rostrum as in female. Antennule as in female, but with three additional aesthetascs at places of dark circles in Fig.
Legs 1–5 as in female. Leg 6 represented by two small setae on genital operculum (Fig.
The specific name of the new species is from Latin foli (a leaf), alluding to the leaf-like inner seta of the maxillule.
Differences between species of Eupolymniphilus are slight. However, E. foliatus sp. nov. can be differentiated from its congeners by the key character, the leaf-like modified inner seta of the maxillule. This seta in other species of the genus is known to be simple and slender. Another characteristic feature of the new species is the presence of thick membranes on the distal part of the mandibular lash.
The length-to-width ratio of the caudal ramus in Eupolymniphilus is somewhat variable among congeneric species. In the female, it is 3.5:1 in E. finmarchicus (Scott T., 1903) according to the illustration of G. O.
Two ♀♀, Site 31, 11 Nov. 2020.
This is a fish-parasitic copepod, living in the gill cavity of the host. Known hosts of this copepod are the gobiid fishes Acanthogobius flavimanus (Temminck & Schlegel, 1845) and A. hasta (Temminck & Schlegel, 1845).
Order Siphonostomatoida Burmeister, 1835
One ♂, Site 4, 19 Jul. 2016; 1 ♀, 1 ♂, Site 11, 03 Jun. 2019; 2 ♂♂, Site 11, 10 Jun. 2020.
One ♀, 1 ♂, Site 11, 10 Jun. 2020; 2 ♀♀, 1 ♂, Site 21, 26 Apr. 2021.
One ♀, 1 ♂, Site 11, 10 Jun. 2020.
One ♀, Site 11, 03 Jun. 2019; 5 ♀♀, Site 11, 10 Jun. 2019; 1 ♀, 10 ♂♂, Site 11, 10 Jun. 2020.
One ♀, 5 ♂♂, Site 1, 28 Jun. 2021; 1 ♀, 4 ♂♂, Site 2, 01 Jul. 2021; 1 ♀, Site 3, 17 Jul. 2016; 10 ♀♀, 41 ♂♂, Site 7, 19 Jul. 2016; 2 ♀♀, 5 ♂♂, Site 12, 16 Mar. 2013; 1 ♀, 4 ♂♂, Site 14, 04 Jul. 2020.
This species is the most frequently found artotrogid copepod in Korean waters; living on sponges, among sea weeds, and on submerged fishing nets in ports (
Five ♀♀, Site 33, 11 Aug. 2020.
This copepod had been found only on the external surface of the tunicate Halocynthia igaboja Oka, 1906.
Holotype ♀ (MABIK CR00250115) and paratypes 3 ♀♀, 2 ♂♂ (MABIK CR00250116) preserved in 90% alcohol, and paratypes 1 ♀, 1 ♂ dissected and mounted on a slide, Site 11 (Yeongdo, Pusan, 35°04'31.0"N, 129°05'08.7"E), 07 Jul. 2020, leg. J. G. Kim. Dissected paratypes (1 ♀, 1 ♂) are retained in the collection of I.-H. Kim.
Female. Body (Fig.
Rostrum absent. Antennule (Fig.
Oral siphon (Fig.
Legs 1–4 (Fig.
Coxa | Basis | Exopod | Endopod | |
Leg 1 | 0-1 | 1–I | I-1; I-1; II, I, 5 | 0-1; 0-2; 1, 2, 3 |
Leg 2 | 0-1 | 1-0 | I-1; I-1; III, I, 4 | 0-1; 0-2; 1, 1+I, 3 |
Leg 3 | 0-1 | 1-0 | I-1; I-1; III, I, 3 | 0-1; 0-2; 1, I, 3 |
Leg 4 | 0-1 | 1-0 | I-1; I-1; III, I, 3 | 0-1; 0-2; 1, I, 2 |
Leg 5 (Fig.
Male. Body form (Fig.
Antennule (Fig.
Oral siphon, mandible, maxillule, maxilla, maxilliped, and legs 1–4 same as those of female. Leg 5 (Fig.
The specific name estivalis is derived from Latin estival (summer), indicating the discovery of the new species in the summer.
The segmentation of the antennule appears to be a reliable character for the differentiation of Acontiophorus species. Aconiophorus estivalis sp. nov. has an 11-segmented antennule in the female; this feature is shared with three congeners, A. antennatus Hansen, 1923, A. scutatus (Brady & Robertson, 1873) and A. zealandicus Sewell, 1944. Acontiphorus antennatus was redescribed by
Two ♂♂, Site 1, 28 Jun. 2021; 1 ♀, Site 3, 17 July. 2016; 1 ♀, Site 4, 03 Jun. 2019; 2 ♀♀, Site 5, 21 Jun. 2016; 1 ♀, Site 6, 21 Sep. 2020; 1 ♀, 2 ♂♂, Site 11, 20 Aug. 2020; 2 ♀♀, 1 ♂, Site 13, 03 Jul. 2020; 6 ♀♀, 6 ♂♂, Site 16, 04 Jul. 2020.
Dermatomyzon nigripes is a cosmopolitan species, and has frequently been collected in Korean coasts. The host of this copepod is still unknown.
Holotype ♂ (MABIK CR00250117) preserved in 90% alcohol, Site 22 (Yesong, Bogil Island, south coast, 34°08'11"N, 126°33'49"E), 26 Apr. 2021, leg. J. Lee and C. Y. Chang; Paratype ♂ dissected and mounted on a slide, Site 15 (Namhae Island, south coast, 34°45'00.5"N, 127°54'33.9"E), 04 Jul. 2020, leg. J. G. Kim. Dissected paratype is retained in the collection of I.-H. Kim.
Male. Body (Fig.
Thermocheres pacificus sp. nov., male A habitus, dorsal B urosome, ventral C rostrum D antennule (open circles indicate insertions of aesthetascs on opposite surface) E antenna F oral siphon G mandible and maxillule H maxilla I distal part of maxilla. Scale bars: 0.1 mm (A, B, F); 0.05 mm (C, D, G, H); 0.02 mm (E, I).
Rostrum (Fig.
Oral siphon (Fig.
Legs 1–4 (Fig.
Coxa | Basis | Exopod | Endopod | |
Leg 1 | 0-1 | 1-1 | I-1; I-1; III, 5 | 0-1; 0-2; 1, 2, 3 |
Leg 2 | 0-1 | 1-0 | I-1; I-1; III, I, 5 | 0-1; 0-2; 1, 2, 3 |
Leg 3 | 0-1 | 1-0 | I-1; I-1; III, I, 5 | 0-1; 0-2; 1, 1+I, 3 |
Leg 4 | 0-1 | 1-0 | I-1; I-1; III, I, 5 | 0-1; 0-2; 1, I, 2 |
Leg 5 (Fig.
Female. Unknown.
The specific name of the new species refers to its discovery in the Pacific Ocean, in contrast with the Indian Ocean in which the type locality, Madagascar, of the type species is located.
The discovery of this new species reinforces the taxonomic status of the genus Thermocheres. The type species of the genus, T. validus Kim, 2010, was described as an associate of a sponge in Madagascar (
Caligus amblygenigtalis Pillai, 1961: 98, figs 8, 10; Ho and Lin, 2003: 56, figs 1, 2. Caligus longipedis: Ho and Lin, 2001: 188, fig. 9 (male only).
Two ♀♀, 5 ♂♂ (MABIK CR00250989–CR00250995), Site 7, 21 Nov. 2019; 1 ♂, Site 11, 10 Jun. 2019.
Female. Body (Fig.
Antennule (Fig.
Mandible with 12 teeth on distal blade. Maxillule (Fig.
Leg 1 (Fig.
Male. Body (Fig.
Antennule (Fig.
Leg 1 (Fig.
Caligus amblygenitalis was originally described by
One ♀, Site 19, 04 Jun. 2020.
This species had been placed in the genus Pseudocaligus, which is now synonymized with Caligus through a molecular analysis (
One ♀, 2 ♂♂, Site 21, 26 May 2017; 1 ♂, Site 25, 06 Jul. 2016; 1 ♂, Site 26, 06 Jul. 2016; 3 ♀♀, 3 ♂♂, Site 27, 09 Jul. 2016; 2 ♀♀, 6 ♂♂, Site 28, 07 Jul. 2016; 4 ♀♀, 1 ♂, Site 29, 09 Jul. 2016; 1 ♀, Site 30, 17 Oct. 2020.
Caligus orientalis is a parasite of coastal marine and brackish-water fish in the East Asian waters. It has a wide host range and has been reported from over 20 fish species of different orders and families (
One ♂, Site 15, 04 Jul. 2020; 7 ♀♀, 12 ♂♂, Site 19, 04 Jun. 2020; 4 ♀♀, 7 ♂♂, Site 20, 06 Jun. 2020; 20 ♀♀, 5 ♂♂, Site 22, 31 May 2021.
This caligid is common on the gobiid fishes living in brackish-waters in Korea.
Two ♀♀, 1 ♂, Site 10, 13 Oct. 2015.
The genital complex of the female of this caligid is characteristically triangular. The only known host of this copepod was Halichoeres poecilopterus (Richardson, 1846) which has been treated as a junior synonym of Parajulis poecilepterus (Temminck & Schlegel, 1845).
Four ♀♀, 1 ♂, Site 11, 16 Apr. 2014; 1 ♀, 1 ♂, Site 20, 05 Jun. 2020; 1 ♀, Site 26, 06 Jul. 2016; 1 ♀, 2 ♂♂, Site 31, 15 Nov. 2020.
1 ♀ and 1 chalimus from the skin of the fish Konosirus punctatus (Temminck & Schlegel, 1846), at a market at Gonam, Hadong, south coast (34˚59'47"N, 126˚48'37"E), 25 Jul. 2012, leg. I.-H. Kim.
Body (Fig.
Sternal furca (Fig.
Male. Body (Fig.
Caligus undulatus is distributed in tropical and warm waters of the world, and has been frequently found from plankton samples.
A female specimen from Site 11 exhibited a shrunken genital complex with undulated lateral margins as observed in the type material of
We thank Dr. Jong Guk Kim of the Korea Institute of Ocean Science & Technology (KIOST) for his assistance in collecting samples. This research was supported by the National Marine Biodiversity Institute of Korea (2022M01100) and by the research program of KIOST (Contract No. PEA0016). We thank Prof. G. A. Boxshall and Prof. S. Ohtsuka for their critical comments on the manuscript.