Introduction
Loxoconchidae is a diverse family with 36 described genera (see Brandão et al., 2018). Most of its numerous representatives belong to the genus Loxoconcha Sars, 1866, which, according to Le et al. (2016), accounts for over 200 living and over 300 fossil species. The genus has a worldwide distribution, and 85 species have been recorded in East Asia (Tanaka and Ikeya, 2002). Of these East Asian species, a majority were described from Japan and China and, with the exception of a few representatives, most species are known only from their shell morphology. Loxoconcha was not only studied from the taxonomic and diversity points of view, but also looking at its ontogenetic development(Smith and Akira, 2005) and, more specifically, ontogenetic development of its maxillula (Le et al., 2016). There were several attempts to revise the genus, the most notable one done by Tanaka and Ikeya (2002) who divided Loxoconcha into five species groups based on carapace morphology. Tohru et al.(2005) divided the genus into two species groups based on the distribution of the shell surface pores, while Le and Tsukagoshi(2014) added one more species group. However, all these divisions encompassed only Japanese and/or East Asian Loxoconcha. A numerous Loxoconcha species have been reported from Korea. Lee et al.(2000) provided a list of more than 500 ostracods collected during an environmental survey from around Korea, but no taxonomic description or illustrations accompanied these records. A total of 23 species were attributed to Loxoconcha, but only 10 were named: L. chinzeii Ikeya and Zhou, 1992; L. harimensis Okubo, 1980; L. hattori Ishizaki, 1977; L. japonica Ishizaki, 1968; L. laeta Ishizaki, 1968; L. cf. ozawai Tabuki, 1986; L. tosaensis Ishizaki, 1968; L. cf. tosaensis Ishizaki, 1968; L. uranouchiensis Ishizaki, 1968; L. cf. uranoushiensis Ishizaki, 1968. Recently, Karanovic et al. (2017) reported L. pulchra Ishizaki, 1969 from Korea and provided a brief redescription along with detailed SEM photographs and drawings of the soft parts.
Loxocorniculum Benson and Coleman, 1963 is very closely related to Loxoconcha, and the only difference between the two genera is the presence of hornlike protuberances postero-dorsally Loxoconcha. The validity of Loxocorniculum has been questioned (Tohru et al., 2005) based on the shell characteristics. Currently there are 30 species in the genus around the world (Brandão et al., 2018), but soft parts were described for only four species, including L. mutsuense Ishizaki, 1971, a species described and redescribed from Japan (Okubo, 1980) and only reported from Korea (see the list in Lee et al., 2000). Soft part morphology of Loxocorniculum species further supports validity of the genus.
In comparison to Loxoconchidae, the family Cushmanideidae is not so diverse, including only three genera (Cushmanidea Blake, 1933; Hulingsina Puri, 1958; Pontocythere Dubowsky, 1939) and about 100 species(Brandão et al., 2018). Similarly, to Loxoconchidae, Cushmanideidae is mostly known based on shell morphology of species. Pontocythere is the most specious genus within the family with about 20 species reported from East Asia. Kim and Park (1980) reported three species(P. miurensis (Hanai, 1959); P. japonica (Hanai, 1959); and P. subjaponica Hanai, 1959) but without any taxonomic descriptions or illustrations. Lee et al.(2000) listed nine Pontocythere species from Korea, six of which were named (P. japonica; P. kashiwarensis(Hanai, 1959); P. minuta Ikeya and Hanai, 1982; P. cf. sekiguchii Ikeya and Hanai, 1982; P. spatiosa Hou, 1982; P. subjaponica).
In this paper we provide brief redescriptions and illustrations of the following Loxoconchidae and Cushmanideidae species: Loxoconcha bizenensis Okubo, 1980, L. japonica, L. tosaensis, Loxocorniculum mutsuense, Pontocythere miurensis, and P. xiphoidea Nakao and Tsukagoshi, 2002. Loxoconcha tosaensis was so far known only from its shell morphology and this is the first time its soft parts have been described. In order to facilitate further identification of the growing number of Loxoconcha and Loxocorniculum species from East Asia which are known from both soft parts and the shell, we provide a taxonomic key. In addition, lists of 61 species of Loxoconcha, one species of Loxocorniculum, and 19 species of Pontocythere from East Asia are included.
MaterIals and Methods
Samples were collected either from shallow, littoral regions reaching from the shore, or from the beach interstitial following Karaman and Chappuis method (Karaman, 1935; Chappuis, 1942). In both cases water was filtered through a plankton hand net (mesh size 100 μm). Samples were fixed in 99% Et-OH. Sorting was done under a stereomicroscope (Olympus SZX12) in the Biodiversity Laboratory at Hanyang University. Specimens were dissected and soft parts mounted on slides in CMC10 Mounting Media (Masters Company, Inc.), while carapaces were kept on the micropaleontology slides or mounted on SEM stubs. All drawings were prepared using a drawing tube attached onto a Olympus BX51. For SEM, carapaces were coated with Platinum. SEM photographs were taken at Eulji University with a Hitachi S-4700 scanning electron microscope. Photographs of soft parts were taken using a stereomicroscope (Leica DM2500) connected camera (LMF275). Materials were deposited in the invertebrate collection of the National Institute of Biological Resources(Korea).
Systematics
Class Ostracoda Latreille, 1802
Subclass Podocopa Sars, 1866
Order Podocopida Sars, 1866
Superfamily Cytheroidea Baird, 1850
Family Loxoconchidae Sars, 1925
Genus Loxoconcha Sars, 1866
1. Loxoconcha bizenensis Okubo, 1980(Fig. 1)
Fig. 1. Loxoconcha bizenensis Okubo, 1980. Male. A, Left valve; B, Antennule and Antenna; C, Antenna (High maginification); D, Male copulatory organ.
Synonymy
Loxoconcha bizenensis sp. nov.Okubo(1980): p. 418, Figs. 14, 18ej.
Material examined. One male dissected on slide(NIBR IV0000813442), shell of on micropalaeontology slide(NIBRIV0000813442).
Locality in Korea. Jeollanamdo, Jindogun, littoral, 34° 24.678ʹN 126°19.415ʹE, 04/04/2012, coll. I. Karanovic.Identifier. Ivana Karanovic.
Diagnosis. Small ostracod, less than 1mm long (Fig. 1A). Dorsal margin sinusoid, with greatest height in front of middle. One small hump present anteriorly to caudal process. Posterior margin rounded but with one caudal process terminated at 2/3 of height. Anterior margin rounded. Ventral margin convex and steeply passing into posterior margin. Valves slightly asymmetrical. Surface irregularly reticulated with two ventral ridges. Except for clearly present bulge in eye region, one more smooth bulge posteriorly. Marginal zone with long, straight canals. Hinge of Loxoconcha type (gongylodont). Antennula slender 6segmented all setae thin (Fig. 1B). Antenna 4-segmented with two distal claws (Fig. 1C). Hemipenis robust (Fig. 1D) with broad triangular distal lobe and proximally with additional triangular process tucked closely to distal process.
Distribution. According to Okubo(1980), the species is common in the intertidal zones of rocky shores in the Inland Sea in Japan. This is the first report for Korea.
Remarks. There are a few differences between the original description and our record: the posterior smooth bulge on the shell seems not to be present in the Japanese populations. Contrary to the original description we only detected two (instead of three) ventral ridges on the shell. However, Okubo (1980) did not provide any SEM photographs, therefore the posterior bulge might have been overlooked. Our identification was primarily based on the similarity in hemipenis between Japanese and Korean populations. According to Tanaka and Ikeya (2002) L. bizenensis belongs to the ozawai species group.
2. Loxoconcha japonica Ishizaki, 1968(Fig. 2)
Fig. 2. Loxoconcha japonica Ishizaki, 1968. Female. A, Left valve; B, Right valve; C, Antennule; D, Antenna.
Synonymy
Loxoconcha japonica sp. nov.Ishizaki(1968): p. 28, Pl. 2, Fig. 1; Pl. 6, Figs. 1012.
Loxoconcha japonica IshizakiIshizaki(1971): p. 86, Pl. 3, Fig. 21; Okubo(1980): p. 416, Figs. 12, 13, 18ad; Paik and Lee(1988): Pl. 3, Fig. 17; Tohru et al.(2005): Fig. 1A.
Material examined. One female dissected on slide(NIBRIV0000813441), shell of on micropalaeontology slide(NIBRIV0000813441).
Locality in Korea. Gyeongsangnamdo, Goseonggun, littoral, 34°59.629ʹN 128°26.201ʹE, 04/04/2012, coll. I. Karanovic.
Identifier. Ivana Karanovic.
Diagnosis(female only). Small ostracod, less than 1 mm long (Fig. 2A, B). Dorsal margin broadly rounded. Posterior margin rounded but with one clear caudal process terminated at 2/3 of height. Anterior margin rounded, and narrower than posterior one. Ventral margin straight to slightly concave. Valves not asymmetrical. Surface regularly reticulated. Marginal zone with long, straight canals. Hinge of Loxoconcha type (gongylodont). Antennula slender 6-segmented (Fig. 2C); all setae thin. Antenna 4-segmented with two distal claws(Fig. 2B).
Distribution. Species has been recorded throughout Japan. Paik and Lee (1988) also reported this species from Plio-Pleistocene deposits from Korea. Beside Okubo (1980) this is the second report of the species soft parts.
Remarks. The identification was based only on female specimens, because males have not been collected. Nevertheless, there are no significant differences between the original description and illustrations and our current record. This species belongs to the japonica species group (Tanaka and Ikeya, 2002).
3. Loxoconcha tosaensis Ishizaki, 1968(Figs. 3-5)
Fig. 3. Loxoconcha tosaensis Ishizaki, 1968. A, SEM photograph of Male left carapace; B, Right carapace.
Fig. 4. L. tosaensis Ishizaki, 1968. A, Mandibula; B, Maxillua; C, Vibratory organ; All scale bars are 50 μm.
Fig. 5. L. tosaensis Ishizaki, 1968. A, Male copulatory organ; B, Antenna; Scale bar is 50 μm.
Synonymy
Loxoconcha tosaensis sp. nov.Ishizaki(1968): p. 31, Pl. 2, Fig. 3; Pl. 7, Figs. 6-9.
Loxoconcha tosaensis IshizakiIshizaki(1971): p. 87, Pl. 3, Fig. 18; Tohru et al.(2005): Fig. 1G; Yasuhara and Seto(2006): Fig. 4m.
Material examined. One male dissected on slide(NIBR IV0000813449), shell of on micropalaeontology slide(NIBRIV0000813449).
Locality in Korea. Jeollanamdo, Goheunggun, littoral close to Naro Space Center, 34°27.348ʹN 127°31.216ʹE, 18/08/2013, coll. I. Karanovic.
Identifier. Ivana Karanovic.
Diagnosis (male only). Small ostracod, less than 1 mm long (Fig. 3A, B). In lateral view, carapace oblong, slightly depressed antero-dorsally. Dorsal margin straight. Ventral margin straight to slightly convex around mouth region. Anterior margin broadly rounded. Posterior margin closes down on dorsal margin with angle; but no prominent caudal process. Surface ornamented with relatively regular coarse reticulation throughout. Eye tubercle distinct. Hinge of Loxoconcha type (gongylodont). Antennula 5-segmented with slender segments. Antenna 4-segmented: first segment carrying only spinneret seta (exopod), second segment with one postero-distally reaching middle of the following segment. Penulitmate segment with two setae situated anteriorly on one third of segment’s length, and three setae postero-medially, slightly below external setae, penultimate segment also carrying two short setae postero-distally; terminal segment with two claws(Fig. 5B). Mandibula (Fig. 4A) with two claws and two setae on terminal segment. Mandibular exopod with three setae. Vibratory plate of maxillula with 15 rays; maxillular palp 2-segmented, first segment carrying three setae; terminal segment elongated and with four setae. All maxillular endites with four setae, and third one in addition with one very thick seta situated proximally. Hemipenis (Fig. 5A) with triangular distal part and one additional lateral projection being very similar in shape like distal part; clasping organ withheld internally and in rod-like shape.
Distribution. Species has been reported from Japan, and it was known only from its shell. This is the first report of soft parts.
Remarks. This is the first description of the soft parts of L. tosaensis. It belongs to the uranouchiensisspecies group(Tanaka and Ikeya, 2002).
Genus Loxocorniculum Benson and Coleman, 1963
4. Loxocorniculum mutsuense Ishizaki, 1971(Fig. 6)
Fig. 6. Loxocorniculum mutsuense Ishizaki, 1971. Male. A, Left valve; B, Right valve; C, Antennule; D, Antenna; E, Copulatory organ.
Synonymy
Loxocorniculum mutsuensis sp. nov.Ishizaki(1971): p. 89, Pl. 5, Fig. 11, Pl. 6, Figs. 3, 6, 7, Pl. 7, Fig. 5.
Loxocorniculum mutsuense IshizakiHanai et al.(1977): p. 65; Okubo(1980): p. 424, Figs. 17, 20; Tohru et al.(2005): Fig. 1Q.
Material examined. One male dissected on slide(NIBR IV0000831180), shell of on micropalaeontology slide(NIBRIV0000831180).
Locality in Korea. Jeollanam-do, Boseong-gun, interstitial, 34°40.172ʹN 127°05.424ʹE, 17/08/2013, coll. I. Karanovic.
Identifier. Ivana Karanovic.
Diagnosis. Small ostracod, less than 1mm long (Fig. 6A, B). Carapace sexually dimorphic, males more elongated. Left and right valve similar. Trapezoidal in lateral views, greatest height situated anteriorly. Dorsal margin straight. Anterior margin broadly and obliquely rounded, forming cardinal angle with dorsal margin. Posterior margin narrowly rounded, slightly projecting toward postero-dorsal area. Ventral margin slightly sinuated. Surface pitted. Five ridges on surface: two anterior and three posterior; postero-dorsal one terminating in horn-like protuberance. Eye tubercle prominent. Hinge of Loxoconcha type (gongylodont). Antennula 5-segmented with ancestral segments four and five fused (Fig. 6C). Antenna 4-segmented with two distal claws (Fig. 6D). Hemipenis subtriangular, anterior process narrowly triangular and with one clearly visible strongly sclerified copulatory process, in shape of upward turned hook (Fig. 6D).
Distribution. Species has been reported from Japan(Okubo, 1980), Russia(Schornikov, 2006). This is the first record for Korea.
List of East Asian Loxoconcha and Loxocorniculumspecies(*species with described soft parts; Kspecies reported from South Korea)
1. Loxoconcha alata Brady, 1868
2. Loxoconcha binhaiensis Hou, 1982
3. Loxoconcha bispinosa Hu, 1981
4. Loxoconcha bizenensis*K Okubo, 1980
5. Loxoconcha brevia Hu, 1984
6. Loxoconcha chinzeii Ikeya and Zhou, 1992
7. Loxoconcha crassella Hu, 1984
8. Loxoconcha crispatum(Hu, 1978)
9. Loxoconcha ellipitica Brady, 1868
10. Loxoconcha epeterseni Ishizaki, 1981
11. Loxoconcha fujianensis Zheng, 1987
12. Loxoconcha gigantea Gou, 1981
13. Loxoconcha hanachirusato Yajima, 1982
14. Loxoconcha harimensis*K Okubo, 1980
15. Loxoconcha hataii Ishizaki, 1963
16. Loxoconcha hattorii Ishizaki, 1971
17. Loxoconcha hemicrenulata Ho, 1982
18. Loxoconcha ikeyai Zhou, 1995
19. Loxoconcha japonica*K Ishizaki, 1968
20. Loxoconcha kamiyai Ozawa and Ishii, 2008
21. Loxoconcha kattoiK Ishizaki, 1969
22. Loxoconcha kitanipponica Ishizaki, 1971
23. Loxoconcha kosugii* Nakao and Tsukagoshi, 2002
24. Loxoconcha laetaK Ishizaki, 1968
25. Loxoconcha lilljeborgii*(Brady, 1868)
26. Loxoconcha malayensis Zhao, 1989
27. Loxoconcha modesta Ishizaki, 1968
28. Loxoconcha noharai* Dung and Tsukagoshi, 2014
29. Loxoconcha nozokiensis Ishizaki, 1963
30. Loxoconcha ocellata Bold, 1973
31. Loxoconcha optimaK Ishizaki, 1968
32. Loxoconcha orientalica Hu, 1978
33. Loxoconcha ozawai Tabuki, 1986
34. Loxoconcha paiki Whatley and Zhao, 1988
35. Loxoconcha pashihaiensis Hu, 1979
36. Loxoconcha pleistocenica Hu, 1978
37. Loxoconcha prolaeta Zhou, 1995
38. Loxoconcha pulchra*K Ishizaki, 1968
39. Loxoconcha santosi* Dung and Tsukagoshi, 2014
40. Loxoconcha sesokoensis* Dung and Tsukagoshi, 2014
41. Loxoconcha shanhaiensis* Hu, 1981
42. Loxoconcha sinensis Brady, 1869
43. Loxoconcha subcirculata Gou, 1981
44. Loxoconcha subkotoraforma Ishizaki, 1966
45. Loxoconcha subpulchra Ho, 1982
46. Loxoconcha taiwanensis Zhao and Whatley, 1981
47. Loxoconcha tamakazura Yajima, 1982
48. Loxoconcha tarda Guan, 1978
49. Loxoconcha tarta Hu, 1978
50. Loxoconcha tata Hu, 1978
51. Loxoconcha tosaensis*K Ishizaki, 1968
52. Loxoconcha tosamodesta Ishizaki, 1981
53. Loxoconcha triconicula Zhao and Whatley, 1989
54. Loxoconcha tumulosa(Hu, 1979)
55. Loxoconcha uranouchiensis* Ishizaki, 1968
56. Loxoconcha ventspina Zheng, 1987
57. Loxoconcha viva Ishizaki, 1968
58. Loxoconcha xuwenensis Zheng, 1983
59. Loxoconcha yinggehaiensis(Tanaka and Ikeya, 2002)
60. Loxoconcha zamia(Ishizaki, 1968)
61. Loxoconcha zhejiangensis Zhao, 1984
62. Loxocorniculum mutsuense*K Ishizaki, 1971
Key to East Asian Loxoconcha and Loxocorniculum species with described soft parts(Modified after Okubo, 1980)
1. Valves reticulated ··················································· 2- Valves pitted ························································· 12
2. Greatest height situated behind the middle ············ 3-Greatest height situated medially or in front of the middle ····································································· 5
3. Distal lobe of the hemipenis in the shape of an equilateral triangle ·····································L. lilljeborgii- Distal lobe of the hemipenis not in the shape of equilateral triangle, but with elongated ventral margin ··· ··············································································· 4
4. Tip of the distal lobe filamentous ····L. shanhaiensis-Tip of the distal lobe pointed ··················L. japonica
5. Valve with ventral winglike ridge ventrally ············· ···························································L. harimensis-Valve without ventral winglike ridge ventrally ····· 6
6. Dorsal margin of the valves almost straight in lateral view, especially in males ········································ 7- Dorsal margin rather sinusoid ··············L. bizenensis
7. In males height to length ration of the shell does not exceed 50% ···························································· 8- In males height to length ratio of the shell over 60% ······························································L. tosaensis
8. Terminal segment of mandibular palp with four setae/claws ······································································· 9-Terminal segment of mandibular palp with 5 setae(one small and plumose, 4 longer and simple) ·················· ·································································L. kosugii
9. Terminal segment of mandibular palp with four simple setae ································································ 10-Terminal segment of mandibular palp with two claws and 2 setae ····································L. uranouchiensis
10. Tip of the distal lobe of hemipenis rounded ········· 11-Tip of the distal lobe ending with thin, elongated, fingerlike projection ·····························L. sesokoensis
11. Third thoracopod much larger and longer than first and second thoracopod ·····························L. santosi-Third thoracopod not much larger and longer than first and second thoracopod ·····················L. noharai
12. Valve without lateral ridges ······················L. pulchra-Valves with three posterior and two anterior ridges ·· ·····································Loxocorniculum mutsuense
Family Cushmanideidae Puri, 1974
Genus Pontocythere Dubovsky, 1939
5. Pontocythere miurensis(Hanai, 1959)(Fig. 7)
Fig. 7. Pontocythere miurensis (Hanai, 1959). Female. A, Left valve; B, Right valve; C, Antennule; D, Antenna; E, Copulatory organ.
Synonymy
Cushmanidea miurensis sp. nov.Hanai(1959): p. 299, Pl. 16, Figs. 710.
Cushmanidea miurensis HanaiHanai(1961): Fig. 4A.
Cushmanidea subjaponica HanaiOkubo(1977): p. 135, Figs. 2, 3.
Pontocythere subjaponica HanaiKamiya and Nakagawa(1993): Pl. 1 Figs. 7, 8.
Pontocythere miurensis(Hanai) comb. nov.Hanai et al.(1977): p. 25.
Pontocythere miurensis(Hanai)Nakao and Tsukagoshi(2002): p. 76, Fig. 5AD.
Material examined. One female dissected on slide(NIBRIV0000831179), shell of on micropalaeontology slide(NIBRIV0000831179).
Locality in Korea. Gyeongsangnamdo, Goseonggun, littoral, 34°59.629ʹN 128°26.198ʹE, 31/03/2013, coll. I. Karanovic.
Identifier. Ivana Karanovic.
Diagnosis. Small ostracod, less than 1mm long (Fig. 7A, B). Size about 1 mm. Carapace sub-quadrate in lateral view. Dorsal margin almost straight with one slight groove around middle length. Dorsal margin forming one angle with posterior margin and gently sloping towards anterior margin. Posterior margin almost straight with one caudal process at postero-ventral margin. Caudal process relatively small. Anterior margin more broadly rounded anteriorely than posteriorely. Ventral margin concave in middle. Greatest height situated behind middle. Surface ornamented with few irregular pits and weak ridges, especially in anterior part of shell. Hinge desmodont. Antennula 5-segmented, with relatively robust segments and short, stiff setae (Fig. 7A). Second antenna 4-segmented with two strong claws and one seta (Fig. 7D).
Distribution. Species has been reported from Japan (Hanai et al., 1977), Russia (Schornikov, 2006). This is the first record for Korea.
Remarks. There is confusion in the literature regarding the names L. miurensis and L. subjaponica (Hanai, 1959). Namely, Okubo (1977) reported P. subjaponica (in the paper referred to as Cushmanidea subjaponica) and described the soft parts for the first time. However, Nakao and Tuskagoshi(2002) attributed Okubo’s(1977) finding to P. miurensis. The difference between the two species is a less developed caudal process in P. miurensis than in P. subjaponica, but this is very subtle. It is possible that P. miurensis and P. subjaponica are synonyms, but since the soft parts are known only for one of them, here we follow Nakao and Tsukagoshi(2002)’s opinion and identified the Korean population as P. miurensis due to a slightly less developed caudal process than in P. subjaponica.
6. Pontocythere xiphoidea Nakao and Tsukagoshi, 2002(Fig. 8)
Fig. 8. Pontocythere xiphoidea Nakao and Tsukagoshi, 2002. Male. A, Left valve; B, Right valve; C, Antennule; D, Antenna; E, Copulatory organ.
Synonymy
Pontocythere xiphoidea sp. nov.Nakao and Tsukagoshi(2002): p. 78, figs. 5E-Q, 6.
Material examined. One male dissected on slide(NIBR IV0000813452), shell of on micropalaeontology slide(NIBRIV0000813452).
Locality in Korea. Muui-do, Hanagae Beach, littoral, 37°23.126ʹN 126°24.526ʹE, 26/05/2012, coll. Ivana Karanovic.
Identifier. Ivana Karanovic.
Diagnosis. Small ostracod (less than 1 mm). Carapace elongated in lateral view (Fig. 8A, B), with greatest height situated slightly in front of middle. Dorsal margin rounded, with small groove on left valve behind middle. Posterior margin narrow and with prominent caudal process. Anterior margin also narrow. Ventral margin straight. Surface not pitted, and with several ridges being strong in the anterior part, fading away towards posterior end, and absent in the middle. Antennula 5-segmented (Fig. 8C), antenna 4-segmented (Fig. 8D). Hemipenis with triangular distal process(Fig. 8E).
Distribution. The species has been reported only once from Japan(Nakao and Tsukagoshi, 2002). This is the first record for Korea.
List of East Asian Pontocythere species
(*species with described soft parts; Kspecies reported from South Korea)
1. Pontocythere brevicula Ruan, 1988
2. Pontocythere carpeta(Hu, 1977)
3. Pontocythere formosana(Hu, 1976)
4. Pontocythere granulata(Guan, 1981)
5. Pontocythere huihoi Hu & Tao, 2008
6. Pontocythere japonicaK (Hanai, 1959)
7. Pontocythere kashiwarensisK (Hanai, 1959)
8. Pontocythere littoralis Zhao, 1984
9. Pontocythere mera(Guan, 1981)
10. Pontocythere minutaK Ikeya & Hanai, 1982
11. Pontocythere miurensus*K (Hanai, 1959)
12. Pontocythere sekiguchiiK Ikeya & Hanai, 1982
13. Pontocythere spatiosaK Hou, 1982
14. Pontocythere subjaponicaK (Hanai, 1959)
15. Pontocythere subtriangularis Hou, 1982
16. Pontocythere suprema Hao, 1988
17. Pontocythere triangulata Hou, 1982
18. Pontocythere versicolaria Hu & Tao, 2008
19. Pontocythere xiphoidea*K Nakao and Tsukagoshi, 2002
AcknowledgeMents
We would like thank to Professor Wonchoel Lee for supporting this work. This work was supported by a grant from the National Institute of Biological Resources(NIBR201701201/201801202). This study was also supported by the National Research Foundation of Korea(grant no: NIBR2016R1D1A1B01009806).
References
- Brandao, S.-N., M.-V. Angel, I. Karanovic, V. Perrier and T. Meidla. 2018. World Ostracoda database [Available from: http://www.marinespecies.org/ostracoda, accessed 27 September 2018].
- Chappuis, P.A. 1942. Eine neue Methode zur Untersuchung der Grundwasserfauna. Acta scientiarum mathematicarum et naturalium, Universitas Francisco-Josephina. Kolozsvar 6:3-7.
- Hanai, T. 1959. Studies of the Ostracoda from Japan IV. Family Cytherideidae Sars 1925. Journal of the Faculty of Science, University of Tokyo 11(3):291-308.
- Hanai, T. 1961. Studies of the Ostracoda from Japan: Hingement. Journal of the Faculty of Science, University of Tokyo 13(2):345-377.
- Hanai, T., N. Ikeya, K. Ishizaki, Y. Sekiguchi and M. Yajima. 1977. Checklist of Ostracoda from Japan and its Adjacent Seas. The University Museum, the University of Tokyo, Bulletin no. 12:1-120.
- Ishizaki, K. 1968. Ostracodes from Uranouchi Bay, Kochi Prefecture, Japan. Science Report Tohoku University, 2nd series 40(1):1-45.
- Ishizaki, K. 1971. Ostracodes from Aomori Bay, Aomori Prefecture, Northeast Honshu, Japan. Science Report Tohoku University, 2nd series 43(1):59-97.
- Kamiya, T. and T. Nakagawa. 1993. Ostracode fossil assembleges in the Holocene shell bed found in Takahama-Cho, Fukui Prefecture, Central Japan. Bulletin of Fukui Natural History Museum 1:115-133.
- Karaman, S.L. 1935. Die Fauna unterirdischer Gewasser jugoslawiens. Verhandlungen der Internationalen Vereinigung fur theoretische und angewandte. Limnologie 7:46-53.
- Karanovic, I., H. Yoo, H. Tanaka and A. Tsukagoshi. 2017. One new species and three records of cytheroid ostracods (Crustacea, Ostracoda) from Korea. Journal of Species Research 6(Special Edition):38-50. https://doi.org/10.12651/JSR.2017.6(S).038
- Kim, W.H. and Y.A. Park. 1980. Microbiogenic sediments in the Nagdong Estuary, Korea. The Journal of the Oceanological Society of Korea 15(1):34-48.
- Le, D.D. and A. Tsukagoshi. 2014. Three new species of the genus Loxoconcha (Crustacea, Ostracoda, Podocopida) from the Okinawa Islands, southern Japan. Zootaxa 3796(1):147-165. https://doi.org/10.11646/zootaxa.3796.1.7
- Le, D.D., A. Tsukagoshi and H. Tanaka. 2016. Ontogenetic changes of the maxillula in Loxoconcha (Crustacea, Ostracoda, Podocopida), with a description of a new species from the Okinawa Islands (Japan). Zoologischer Anzeiger 262:43-56. https://doi.org/10.1016/j.jcz.2016.03.009
- Lee, E.H., M. Huh and E.I. Schornikov. 2000. Ostracod Fauna from East Sea Coast of Korea and Their Distribution - Preliminary Study on Ostracoda as an Indicator of Water Pollution -. Journal of the Geological Society of Korea 36(4):435-472.
- Nakao, Y. and A. Tsukagoshi. 2002. Brackish-Water Ostracoda (Crustacea) from the Obitsu River Estuary, Central Japan. Species Diversity 7:67-115. https://doi.org/10.12782/specdiv.7.67
- Okubo, I. 1977. Cushimanidea subjaponica Hanai, 1959, in the inland sea, Japan. Research Bulletin of Okayama Shujitsu Junior College 7:133-140.
- Okubo, I. 1980. Taxonomic studies on recent marine podocopid Ostracoda from the inland sea of Seto. Publications of the Seto Marine Biological Laboratory 25(5/6):389-443. https://doi.org/10.5134/176001
- Paik, K. and E.-H. Lee. 1988. Plio-Pleistocene Ostracods from the Sogwipo Formation, Cheju Island, Korea. Developments in Palaeontology and Stratigraphy. pp. 541-556.
- Schornikov, E.I. 2006. Checklist of the ostracod fauna of Peter the Great Bay, Sea of Japan. Zootaxa 1294:29-59. https://doi.org/10.11646/zootaxa.1294.1.2
- Smith, R.J. and T. Kamiya. 2005. The ontogeny of the entocytheroid ostracod Uncinocythere occidentalis (Kozloff & Whitman, 1954) Hart, 1962 (Crustacea). Hydrobiologia 538:217-229. https://doi.org/10.1007/s10750-004-4965-1
- Tanaka, G. and N. Ikeya. 2002. Migration and speciation of the Loxoconcha japonica species group (Ostracoda) in East Asia. Paleontological Research 6(3):265-284.
- Tohru, I., T. Kamiya and A. Tsukagoshi. 2005. Phylogeny and evolution of Loxoconcha (Ostracoda, Crustacea) species around Japan. Hydrobiologia 538:81-94. https://doi.org/10.1007/s10750-004-4939-3
- Yasuhara, M. and K. Seto. 2006. Holocene relative sea-level change in Hiroshima Bay, Japan: a semi-quantitative reconstruction based on ostracodes. Palaeontology Research 10(2):99-116. https://doi.org/10.2517/prpsj.10.99