• Korean Journal of Ichthyology
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• v.18 no.4
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• pp.347-354
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• 2006

Spermiogenesis in the Zacco koreanus is characterized by lateral development of flagellum, shallow nuclear fossa formation and with no nuclear rotation. These spermatozoa exhibit a spherical head containing a nucleus with the chromatin highly condensed and no acrosome. The midpiece is a small and a short cytoplasmic canal. Mitochondria are separated from the initial segement of the axoneme by cytoplasmic canal. The flagellum contains the classic axoneme structure (9+2) and has a vesicle in the initial region; it dose not have axonemal fins. The presence of a vesicle in the initial region of flagella, a structure common in many Cypriniformes spermatozoa.

• Korean Journal of Ichthyology
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• v.22 no.4
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• pp.225-229
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• 2010

A intergeneric hybrid between Rhodeus uyekii and Acheilognathus signifer was collected in the Jojongcheon Bukhan River. The hybrid showed intermediate characteristics of two parental types in some key characters, such as color pattern of body, pigmentation of dorsal, anal, and caudal fins, and body spot and stripe. In addition, the hybrid had a fairly large number of lateral line scales, while it lacked a barbel, which is known as a key intergeneric character. The probable occurrence of a natural hybrid is supported by a viable $F_1$ hybrid produced with the parental species.

• Korean Journal of Ichthyology
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• v.4 no.2
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• pp.55-62
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• 1992

Study on the fish fauna of the Chuam Dam in Sungju-gun, Chollanamdo, Korea was conducted from March 1990 to October 1990. Twenty-eight species belong to 23 genera and 11 families have been collected at five areas within the dam. The dominant species were Zacco platypus, Acheilognathus limbata and Zacco temmincki. Among the collected fishes, 5 species were known to be endemic species in Korea. They were Acheilognathus yamatsutae, Sarcocheilichthys variegatus wakiyae, Coreoleuciscus splendidus, Microthysogobio yaluenis, Cobitis longicorpus, Pseudobagrus koreanus, Liobagrus mediadiposalis and Odontobutis platycephala. The frequencies occurrence were 86.71% for 5.2% for Cyprinidae and Osmeridae.

• Korean Journal of Environmental Biology
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• v.24 no.1 s.61
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• pp.29-37
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• 2006

We investigated the feeding habits of Rhynchocypris kumgangensis in Hongcheon River of Saenggokri, Seoseokmyeon, Hongcheongun, Gangwon-do, Korea from April 2002 to March 2003. The fish is korean endemic species upper streams in Korea. It was asscertained that R. kumgangensis is a carnivore and consumes mainly Ephemeroptera, Diptera, Terrestrial insects and Trichoptera. The most important prey was chironomids: Chironomus sp. Their feeding habits changed according to growth. Small fish fed mainly on small prey organisms such as Diptera, while larger fish fed much more on Ephemeroptera and Terrestrial insects. There were also seasonal changes in the relative proportion of their food items.

• Journal of Aquaculture
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• v.22 no.1
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• pp.83-91
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• 2009

The Korean doty barbel Hemibarbus mylodon (Cypriniformes; Cyprinidae) is a critically endangered freshwater fish species mainly because of its natural habitat degradation. Three full-length complementary DNA (cDNA) clones representing different muscle actin isoforms were isolated and characterized. The three muscle actin isoforms were 1,294-1,601 bp long with the identical open reading frames of 1,134 bp with the deduced amino acid residues of 377. They showed 83.9-87.2% identities in the coding nucleotide level and 96.8-98.1% identities in the amino acid level. Phylogenetic analysis with the coding nucleotide sequences revealed that three muscle actin isoforms of H. mylodon formed strongly supported monophyletic groups with one of cypriniform skeletal $\alpha$-actin (acta1), cypriniform aortic $\alpha$-actins (acta2), and uncharacterized Danio rerio muscle actin isoform/Salmo trutta slow muscle actin (a novel muscle actin type). Our phylogenetic tree further suggested that cypriniform acta2 only showed the orthologous relationship to tetrapod acta2. Other multiple actin isoforms from diverse teleostean taxa were however clustered to no tetrapod orthologs, i.e., acta1, cardiac $\alpha$-actins (aetc1), acta2, and enteric $\gamma$-actin (actg2). This result strongly suggested that teleostean muscle actins have experienced different and complicated evolutionary history in comparison to mammalian counterparts.

• Korean Journal of Ichthyology
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• v.19 no.3
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• pp.253-256
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• 2007

The chromosome numbers of two species (Culter brevicauda and Erythroculter erythropterus) of Korean Cultrinae are investigated. In two species, the mitotic chromosomes from 24 groups with two chromosomes each indicated that it is a diploid. Their karyotypes and total length of chromosomes were slightly different from each other. The karyotype of C. brevicauda and E. erthropterus is 2n=48 (7M+10SM+7ST), FN=96 and 2n=48 (6M+10SM+8ST), FN=96. Observed chromosomes of C. brevicauda and E. erythropterus ranged from 5.4 to $2.2{\mu}m$ and 6.1 to $2.3{\mu}m$ in length, respectively.

• Korean Journal of Ichthyology
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• v.21 no.1
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• pp.55-60
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• 2009

Korean bitterling Acanthorhodeus gracilis Regan, 1908 is very similar to Acheilognathus chankaensis (Dybowski, 1872) having 12~14 dorsal fin rays, 10~11 anal fin rays and 35~36 lateral line scales. By analyzing these specimens and original descriptions, diagnostic characteristics of the genus Acanthorhodeus were included in the genus Acheilognathus and Acanthorhodeus gracilis was defined as a junior synonym of Acheilognathus chankaensis. The provisional keys are provided for identifying the nine species of Acheilognathus from Korea.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.56 no.5
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• pp.676-683
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• 2023

The development of the egg, larvae, and juveniles of Acheilognathus macropterus from the Wicheon stream of Nakdonggang River was investigated for early life history characteristics. The fish used in the study were collected from Wicheon stream located in Bian-myeon, Uiseong-gun, Gyeongsangbuk-do. The fertilized egg was 1.88±0.09 mm (n=30) in long diameter and 1.34±0.06 mm (n=30) in short diameter. After fertilization at a water temperature of 20℃, the egg took 31 h and 40 min to hatch. Newly hatched larvae had an average total length of 3.92±0.13 mm (n=30) and possessed a yolk sac the mouth and anus were not developed. Twenty days after hatching, the postflexion larvae had an average total length of 8.08±0.29 mm (n=30), with the tail tip fully bent at 45° and began feeding. Thirty-three days after hatching, the number of fin stems reached an integer with an average total length of 15.0±1.08 mm (n=30). In this study, differences in the egg size, hatching time, melanophore development period, and distribution location were confirmed between A. macropterus and allied species.

• Korean Journal of Environment and Ecology
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• v.30 no.1
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• pp.48-57
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• 2016

The distribution of fish (Cobitidae and Cyprinidae) and amphibians together with related environmental factors were surveyed at 30 randomly selected rice-fields (15 flooded unmanaged rice fields (FUR) and 15 unflooded managed rice fields (UMR)) near the Yedang reservoir in Korea, eight times from May to August in 2012. The total number of species captured from the entire survey area was 13 species with 8 families of fish and 5 species of amphibians. The number of species of Cyprinidae fish captured in FUR was higher than that in UMR. Upon the comparative analysis on the distribution of fish and amphibians in FUR and UMR, it was found that the number of Cyprinidae fish captured in FUR was significantly higher than that in UMR while the number of Cobitidae fish captured in UMR was higher than that in FUR. According to the analysis on the environmental factors that affect the distribution of fish, Cyprinidae fish tend to appear in rice-fields, that were flooded in winter, near the Yedang reservoir while Cobitidae fish tend to appear in rice fields that draws its water supply from forest reservoir and have a good water drainage system. In case of amphibians, the number of tadpoles captured in UMR was higher than that in FUR. Rana catesbeiana was dominant in FUR and Rana nigromaculata was dominant in UMR. Upon the analysis on the environmental factors that affect the distribution of tadpoles, it was found that Rana catesbeiana tadpoles tend to appear in rice fields, that were flooded in winter, near Yedang reservoir while Rana nigromaculata tadpoles tend to appear near mountains and far from the Yedang reservoir.

• Korean Journal of Ichthyology
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• v.26 no.3
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• pp.179-184
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• 2014

A histological study on the egg envelope and oogenesis of Gobiobotia brevibarba (Pisces, Cyprinidae) was carried out by a light microscope and a scanning electron microscope. Various developmental cells appeared in the ovary caught during May 2014, spawning season. For the relative area of oocyte, the ovary consisted of mature stage (74.5%), a vitellogenic stage (yolk granule stage, 16.6% and yolk vesicle stage, 6.6%) and previtellogenic stage (perinucleolus stage 2.2%), which means its spawning season. The cytoplasm of the perinucleolus oocyte is acidic and many nucleoli are located at the inner side of the nuclear membrane. The yolk vesicles, an early vitellogenic stage, has a follicular layer and a zona radiata clearly. Numerous villi, called an egg envelope, begin to form on the zona radiata. The yolk granules, an another vitellogenic stage, proceeds and they show a strong eosinophilic nature. Such yolk granules appeared between the yolk vesicles occupying most cytoplasm, and as the stage proceeds, there are some yolk masses fused with each other. Egg envelope is covered with plenty of villi ($2{\sim}3{\mu}m$ in the length) over the entire egg surface.