• Korean Journal of Ichthyology
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• v.22 no.2
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• pp.96-104
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• 2010

During an artificial breeding as a part of restoration of the endangered Korean bitterling Acheilognathus signifer, a small number of individuals exhibiting oculocutaneous albinism were produced. We compared the pigmentation and morphology of normal and albinic bitterlings by histological examination of skin samples obtained from 10 regions on the body, fins, and eyes. There were no differences in morphometry and in general morphology of skin between them. In normal bitterlings, pigment cells were better developed in the dorsal region, the upper part of caudal peduncle region, the choroid-retinal epithelium and iris than in other areas. In the albinic bitterling, however, pigment cells were present only in three parts of the dorsal region, the caudal and dorsal fin, which had few melanin cells. Albinic bitterlings also displayed deficient pigmentation in the choroid-retina pigment epithelium and iris. Although they had different pigmentation aspects in distribution and development between normal and albinic bitterlings, melanin cells were mainly present in the dorsal regions of the skin and eyes where are exposed directly to light.

• Korean Journal of Ichthyology
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• v.1 no.1_2
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• pp.83-92
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• 1989

The pharyngeal teeth and the masticatory process of the basioccipital bone were compared in ten species of Korean bitterlings. Three species, Acheilognathus lanceolata, A. limbatus, A. signifier and Rhodeus ocellatus, which are characterized by the absence of serrations on the side of the pharyngeal teeth, are found to, have reduced occlusal grooves on the outside of occlusal margin, Among Korean bitterlings, differences are found in the developmental degrees of the anterior part of the masticatory process, the grooves on the occlusal surface and the chewing area on the pharyngeal first tooth. The occlusal grooves in herbivorous species are considered to be more developed than those in omnivorous species. Considering these findings, the combination of developmental degrees in the three pharyngeal elements suggests generally the phylogenetic relationships among the Korean bitterlings.

• The Korean Journal of Zoology
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• v.32 no.1
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• pp.22-33
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• 1989

Comparison of morphological characters and development of eggs and larvae of two bitterlings, Acheilognathus limbata and A. signifer from Korea were observed and discussed taxonomically. A. signifer differs from A. limbata by the color pattern of dorsal and anal fin ray of male, egg form and the length of ovipositor of female. Although two species are overlapping each other in some morphometric characters, there is a great difference between the two in the multivariate analysis of 15 morphological characters of five comparative populations. These results indicate that A. limbata and A. signifer are two independent allopatric sibling species in Korea.

• Korean Journal of Ichthyology
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• v.7 no.1
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• pp.18-24
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• 1995

The spawning condition was investigated of the bitterling, Acheilognathus yamatsutae Mori in aquariums. Sexual responses in male and female bitterlings were very sensitive to the mussel rather than the other sex. But spawning behavior was shown ouly when all of the male, the female and the mussel were present. And the sexual response was not shown at all when there was no direct contact with the live mussel.

• Parasites, Hosts and Diseases
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• v.56 no.1
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• pp.41-48
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• 2018

The infection status of Clonorchis sinensis metacercariae (CsMc) was examined in freshwater fish from a highly prevalent site, Wicheon (a branch of Nakdong-gang), which is located in Gunwi-gun, Gyeongsangbuk-do, the Republic of Korea. Total 1,162 fish in 32 species were examined by the artificial digestion method through 6 years. CsMc were detected in 720 (67.5%) out of 1,067 fish (26 spp.) and their density was 610 per fish infected. In the susceptible gobioninid fish group, i.e., Pungtungia herzi, Squalidus gracilis majimae, Squalidus japonicus coreanus, Sarcocheilichthys variegatus wakiyae and Pseudorasbora parva, all of 323 fish were infected with an average of 1,310 CsMc. Total 23 (95.8%) gobioninid fish, i.e., Pseudogobio esocinus, Abbottina springeri, Hemibarbus longirostris, Microphysogobio koreensis, and Microphysogobio jeoni, were infected with 127 CsMc in average. In the acheilognathinid fish (bitterlings) group, the prevalence was 77.0%, and the density was 50 CsMc per fish infected. In the rasborinid fish (chubs) group, i.e., Zacco platypus, Zacco temminckii, Zacco koreanus, and Opsariichthys uncirostris amurensis, 147 (36.5%) out of 403 fish examined were infected with 15 CsMc in average. The susceptibility indices of CsMc were 412 in the overall positive fish group, 1,310 in the gobioninid group-1, 122 in the gobioninid group-2, 38.5 in the acheilognathinid group, and 5.5 in the rasborinid fish group. Conclusively, it was confirmed that CsMc are highly prevalent in fish from Wicheon, and their infection tendency varied according to the subfamily groups in Cyprinidae fish hosts.

• Journal of Aquaculture
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• v.22 no.1
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• pp.79-82
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• 2009

Reciprocal interspecific hybrids between two bitterling species Rhodeus uyekii (RU) and R. notatus (RN) were genetically identified based on the partial sequence analysis of recombination activating gene-1 (RAG-1) gene. Out of 863 bp positions analyzed, 13 nucleotide substitutions were detected between the two parental species (RU and RN genotypes). Both the induced hybrids (RU female$\times$RN male; UN genotype) and their reciprocal counterparts (RN female$\times$RU male; NU genotype) displayed the double peaks (or polymorphism) of sequence chromatograms at the 13 diagnostic positions, indicating that those hybrids were actual karyogamy derived from the two parental haploid genomes. However, it was not possible to distinguish between the reciprocal interspecific hybrids.

• Parasites, Hosts and Diseases
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• v.57 no.2
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• pp.145-152
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• 2019

The infection status with Clonorchis sinensis metacercariae (CsMc) was examined in freshwater fishes from Yangcheon (a branch of Gyeongho-gang), which is located in Sancheong-gun, Gyeongsangnam-do, the Republic of Korea. Total 2,201 fishes in 26 species were examined by the artificial digestion method through 7 years. CsMc were detected in 1,171 (53.2%) fishes in 21 spp. (80.8%) and their density was 85 per fish infected. Total 532 (99.6%) out of 534 Pungtungia herzi (index fish) examined were infected with 147 CsMc per fish infected. Metacercarial densities in this fish were highest in 2015 (179 CsMc), followed by 2012 (168), 2013 (152), 2016 (145), 2014 (114), and 2017 (89) respectively. In the gobioninid fish group, i.e., P. herzi, Sarcocheilichthys spp., Squalidus spp., Pseudogobio esocinus, Hemibarbus longirostris, and Hemibarbus labeo, 841 (92.7%) fishes were infected with 117 CsMc per fish infected. Total 250 (54.7%) acheilognathinid fish (bitterlings), Acheilognathus spp. and Acanthorhodeus spp. were infected with 5.8 CsMc. In the rasborinid fish (chubs) group, i.e., Zacco platypus, Zacco temminckii, and Zacco koreanus, 77 (13.7%) out of 563 fish examined were infected with 2.4 CsMc in average. The susceptibility indices of CsMc were 49.09 in the overall positive fish group, 104.15 in the gobioninid group, 3.17 in the acheilognathinid group and 0.35 in the rasborinid fish group respectively. Only 1 CsMc was detected in 3 fish species, Coreoperca herzi, Channa argus, and Lepomis macrochirus, respectively. Conclusively, it was confirmed that CsMc are moderately prevalent in fishes from Yangcheon in Sancheon-gun, Gyeongsangnam-do, Korea.

• Korean Journal of Environmental Biology
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• v.41 no.3
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• pp.229-246
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• 2023

The bitterling (Cyprinidae, Acheilongnathinae) is a temperate freshwater fish with a unique spawning symbiosis with host mussels. Female bitterlings use their extended ovipositors to lay eggs on the gills of mussels through the mussel's exhalant siphon. In the present study, in April of 2020, we investigated spawning frequencies and patterns of three bitterling fish species in host mussel species in the Nakdong River basin (Hoecheon). During field surveys, a total of four bitterling and three mussel species were found. We observed bitterling's spawning eggs/larvae in the three mussel species: Anodonta arcaeformis(proportion spawned: 45.5%), Corbicula fluminea(12.1%), and Nodularia douglasiae (45.2%). The number of bitterlings' eggs/larvae per mussel ranged from 1 to 58. Using our developed genetic markers, we identified the eggs/larvae of each bitterling species in each mussel species (except for A. macropterus): A. arcaeformis (spawned by Acheilognathus yamatsutae), C. fluminea (A. yamatsutae and Tanakia latimarginata), and N. douglasiae (A. yamatsutae, Rhodeus uyekii, and T. latimarginata). Approximately 57.6% of N. douglasiae mussel individuals had eggs/larvae of more than one bitterling species, suggesting that interspecific competition for occupying spawning grounds is intense. This is the first report on bitterling's spawning events in the Asian clam C. fluminea from Korea; however, it should be ascertained whether bitterling's embryo undergoes successful development inside the small mussel and leaves as a free-swimming juvenile. In addition, the importance of its conservation as a new host mussel species for bitterling fishes needs to be studied further.

• Korean Journal of Ichthyology
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• v.26 no.4
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• pp.288-294
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• 2014

Host mussel utilization for spawning of the oily shinner, Sarcocheilichthys variegatus wakiyae (Pisces: Cyprinidae), from Korea was investigated in part of the Dalcheon (river) in Cheongcheon-myeon, Goesan-gun, Chungcheongbuk-do, Korea from April to June 2011, 2013. The non-synchronicity of mature and immature eggs obtained from females of S. v. wakiyae and the number of spawned eggs found was less than those in the mussels, suggesting that these fish may be batch spawners. Five species of freshwater mussels - Unio douglasiae sinuolatus, Lanceolaria grayana, Anodonata arcaeformis flavotincta, Lamprotula leai, Corbicula fluminea - were found at the survey area (wild conditions) but three species of freshwater mussels - A. a. flavotincta (oviposition rate, 50.0%), U. d. sinuolatus (16.2%), L. leai (11.1%) - were host of S. v. wakiyae. Spawning of S. v. wakiyae occurred mainly in the mantle cavity (wild conditions, 77.4%; experiment, 62.8%) of the mussels that were connected more to the inhalant siphon than the suprabranchial cavity (22.6%; 31.8%) that linked to the exhalant siphon. Bitterlings prefer to lay eggs in L. leai and S. v. wakiyae prefers A. a. flavotincta as a spawning host. These were considered to be the result of niche partitioning.

• Korean Journal of Ichthyology
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• v.1 no.1_2
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• pp.73-82
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• 1989

The development of eggs and larvae, and minute scale-like tubercles on the skin surface of the larval Acanthorthodeus asmussi from Korea were observed in the laboratory. The egg was nearly ovoid-shaped. The number of egg averaged 195 per an oviposition. The morphological character of larval development was relatively similar to those of Acheilognathus tabira tabira, A. tabira subsp. (a), A. yamatsutae, A. moriokae, A. cyanostigma and A. rhombeus. The larvae of this species had many scale-like tubercles ellipsoided in a diagonal cross section on the skin surface of the body. And also this species moved like incessant wiggly movement pattern as that of fly maggot duing the larval development. As regards the tubercles and larval movement pattern, the larvae of A. asmussi shared similar characters with those of Acheilognathus rhombeus, A. longipinnis and Pseudoperilampus typos. Hence A. asmussi may be closely related to these species. The latter three species are autumn-spawning bitterlings and the larval development always retard in a certain stage, while A. asmussi is a spring-summer spawning species and the larval development never retards. Judging from these facts, it should be considered that there are close relations in evolutionary trend between the two spawning species.