• Korean Journal of Ichthyology
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• 제2권2호
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• pp.159-168
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• 1990

Parental fish of R. uyekii(Mori) were colleted from the Nakdong River, Korea. Artificial insemination was carried out 4 times during June using the same pair (a female 52.70 mm TL and a male 56.80 mm TL). Unfertilized eggs are nearly spindly, opaque yellow in colour, measuring about 3.20-3.50 mm in length, about 1.50-1.80 mm in breadth. Hatching began about 50 hours after insemination at water temperature of $16.5{\sim}18.5^{\circ}C$. The newly hatched larvae are 4.10-4.50 mm in total length(TL), with 29-30 myomeres. Nine days after hatching, the larvae averaged 8.40 mm in total length and caudal notochord flexed at $45^{\circ}$. Eighteen days after hatching, total length reached 8.90 mm. The part of the fin-fold of the future dorsal and anal fins became high. Twenty-eight days after hatching, total length was 9.35 mm. The caudal fin-rays began to fork into two branches. The increased number of melanophores appeared newly on the head dorsal and anal fin-rays. The larvae reached the juvenile stage at 50-60 days after hatching and attained 14.50-16.20 mm in total length, and all fin-rays was formed.

• Korean Journal of Ichthyology
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• 제24권1호
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• pp.48-55
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• 2012

Egg development and early life history of the slender shinner, $Pseudopungtungia$ $tenuicorpa$ were investigated to provide basic information regarding biological characteristics and restoration in 2010. Eggs were obtained by injecting females with Ovaprim and then fertilized using the dry method in the laboratory. Matured eggs were strongly adhesive, opaque and grayish and measured $1.96{\pm}0.08mm$(mean${\pm}$SD) in diameter. Fertilized eggs hatched 240 h after fertilization at $23^{\circ}C$, and newly hatched larvae an average $8.6{\pm}0.25mm$ in total length. At 2 days after hatching, larvae averaged $9.0{\pm}0.37mm$ in total length and their yolk sacs had been completely absorbed. About at 10 days after hatching, they beacme to juvenile stage and reached $10.6{\pm}0.44mm$ in total length. At 70 days after hatching, the band patterns and external form of juveniles were similar to those of adults, and they averaged $36.0{\pm}2.13mm$ in total length.

• Korean Journal of Ichthyology
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• 제29권1호
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• pp.1-12
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• 2017

A natural hybrid of interspecific between the Coreoleuciscus splendidus and C. aeruginos (Cypriniformes: Cyprinidae) was captured in the Hwang-ji Stream, a tributary of the Nakdong River basin in Korea. An interspecific hybrid between C. splendidus and C. aeruginos was genetically identified based on morphological characteristics and the sequence analysis of nuclear recombination activating gene 1 (RAG1) gene (1,334 bp) and mitochondrial cytochrome c oxidase subunit 1 (CO1) gene (1,551 bp). As a result of morphological variations, the natural hybrid appeared to have an intermediate character between two parental species (C. splendidus and C. aeruginos) in three variations of black array (s) on dorsal, caudal and anal fin rays. Phylogenetic analysis inferred from RAG1 and CO1 sequence data revealed that Coreoleuciscus populations from Hwang-ji stream consist of two pure Coreoleuciscus species and a hybrid individual group. The individuals were clearly identified the cross and reciprocal hybrid by CO1 gene analysis. In RAG1 gene, 13 nucleotide variation loci were detected and the hybrid individuals displayed the double peaks of sequence chromatograms at the 9 diagnostic positions. In this study, molecular data and morphological variations were clearly demonstrated that hybridization did occur between C. splendidus and C. aeruginos. However, F2 hybrid generation and reproductive capacity of F1 hybrid individuals were not demonstrated.

• Korean Journal of Ecology and Environment
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• 제33권4호통권92호
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• pp.405-412
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• 2000

The fine structure of spermatozoa of Leiocassis ussuriensis was examined with scanning and transmission electron microscopies. The spermatozoon of L. ussuriensis is approximately $68.8\;{\mu}m$ in length and a relatively simple cell with a spherical nucleus, a short midpiece and a tail. The ultrastructure of spermatozoa of L. ussuriensis is characterized by the following features. The nuclear fossa, the length of which is about two-thirds of the nuclear diameter, contains two centrioles. The centrioles are orientated approximately $180^{\circ}$ to each other. The mitochondria are arranged in two layers and their number is 12 or more. The axoneme is the 9+2microtubular pattern and has inner but no outer dynein arms as in other bagrids. The two axonemal fins are in the same plane with the two central microtubules, the doublets 3 and 8. The axonemal fins and the inner dynein arm are shared in Bagridae and the deep nuclear fossa is shared in Siluriformes. The axonemal finsobse observed in Bagridae and Amblycipitidae of Siluriformes might be the apomorphic character in Ostariophysi. They are not reported in Cyprinidae and Characiformes.

• Korean Journal of Fisheries and Aquatic Sciences
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• 제18권4호
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• pp.381-400
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• 1985

Twelve species of subfamily Leuciscinae from Korea are reviewed and keys to species and genera are provided. The species include Tribolodon hakonensis, T. branti, Phoxinus phoxinus, Moroco oxycephalus, M. steindachneri, M. keumgang, M. semotilus, Zacco platypus, Z. temminckii, Opsariichthys uncirostris amurensis, Aphyocypris chinensis and Squaliobarbus curriculus. In the present study M. lagowskii and O. bidens recorded previously in Korea have to be classified to M. steindachneri and O.u.amurensis based on several characters such as caudal peduncle depth, their distributions and lateral line scales, etc. A. chinensis from Korea is easily distinguished from that of mainland China in head length and caudal peduncle length. The skull and weberian apparatus of M. keumgang, endemir to Korea are described and compared with the other species of this subfamily. The diploid chromosome number of 9 species has three patterns: 2n=50 (T. hakonensis, P. phoxinus, M. oxycephalus, M. steindachneri and M. keumgang), 2n=48(Z. platypus, Z. temminckii and A. chinensis), 2n=76 (O. u. amurensis). Polyploidization or intraspecific polymorphism of chromosome was not observed in any species studied. Both species of P. phoxinus and A. chinensis are shown to be electrophoretically distinct from other taxa examined. The genera of subfamily Leuciscinae in Korea are represented by three possible groups: 1) Zacco-Opsariichthys-Tribolodon-Phoxinus-Morco, 2) Aphyocypris, and 3) Squaliobarbus.

• Journal of Korean Society on Water Environment
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• 제31권6호
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• pp.665-679
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• 2015

Yearly mean temperature in the 29 lakes surveyed ranges from 12.6 (Suncheon) to 13.9℃ (Mokpo), the lowest in −2.7℃ (January) and the highest in 25.9℃ (July). Monthly mean the amount of rainfall recorded the highest of 336.7 mm in August and the lowest with 4.9 mm in January. A total of 424 species of phytoplankton were identified. They were 157 Chlorophyceae, 161 Bacillariophyceae, 39 Cyanophyceae, and 67 other algal taxa. The phytoplankton diversity were low in stream type reservoirs such as Guemho, Youngsan and Youngam. The population density of phytoplankton ranged from 19 to 53,161 cells/ml. Annual mean of total zooplankton abundance in 45 sites was 369±827 ind./L (n=180). Rotifers were the most common taxa and their relative abundance was high (65~77%). The benthic microinvertebrate fauna of 10 reservoirs of Jeonnam province were 71 species of 61 genera of 44 families of 16 orders of 7 classes of 4 phyla. Aquatic insects of Phylum Arthropoda were 50 species of 44 genera of 28 families of 6 orders. The number of individuals was 6,132. Diptera was highiest (41.3%), and Ephemeroptera (31.0%), Trichoptera (17.5%), Anellida (3.8%), Mollusca (3.3%), Crustacea (0.4%). Large hydrophytes were identified 32 taxa, 2 varieties 30 species 26 genera and 20 families. Especially, Jijung and Juam lakes require management such as physical remove of this ecosystem disturbance field plants. Fishes were identified total 44 taxa, such as 25 Cyprinidae (56.8%), 8 Cobitidae (17.0%), 3 Gobiidae (6.4%), 2 Bagridae (4.3%), 2 Osmeridae (4.3%), 2 Odontobutidae (4.3%), 2 Centrachidae (4.3%), 1 Siluridae (2.1%), and 1 Centropomidae (2.1%). A pale chub was dominant species (18.9%).

• Korean Journal of Environmental Biology
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• 제32권4호
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• pp.319-326
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• 2014

Fish community was investigated in eutrophic Jeondae agricultural reservoir from April to November 2012. The food web structure of major fish species of Jeondae reservoir showed that due to serious organic pollution, the hyper-eutrophic condition with high chemical oxygen demand (COD), chlorophyll-a (Chl-a), total nitrogen (TN) and total phosphorus (TP), as estimated by stable isotope analysis. Total of 679 individuals were collected from the reservoir, and 9 species were identified. Interestingly, Lepomis macrochirus and Hemiculter eigenmanni known as less sensitive to pollution and water quality deterioration, dominated the reservoir, and their relative abundances were 38% and 27%, respectively. Further, the analysis of the stomach contents revealed that main food source of dominant L. macrochirus was high amount of zooplankton, which includes copepoda and cladocera, while Cyprinidae species mainly consumed organic particles with zooplankton preys. Stable isotope analysis also suggested that L. macrochirus, Carassiusauratus, Pseudorasboraparva, and H. eigenmanni are major zooplantivorous group in the Jeondae Reservoir.

• Korean Journal of Ecology and Environment
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• 제44권2호
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• pp.136-143
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• 2011

Early life history of the endangered species Gobiobotia brevibarba was investigated to provide baseline data for biological characteristics and restoration. Adult fish were sampled by spoon net capture at Hongcheon-gun, Gangwon-do, Korea, in April 2010. Eggs were obtained after injection of Ovarprim and were artificially fertilized by the dry method in the laboratory. The mature eggs were slightly adhesive and transparent with greyish and average $1.24{\pm}0.07$ mm in diameter. The hatching of the embryos took place about 120 h after fertilization at a water temperature of $23^{\circ}C$. The newly-hatched larva averaged $5.5{\pm}0.29$ mm in total length. Four days after hatching, they averaged $7.4{\pm}0.26$ mm in total length and their yolk sacs were completely absorbed. From 15 days after hatching, they entered the juvenile stage and reached $9.9{\pm}0.72$ mm in total length. One hundred days after hatching, their band patterns and external form were similar to those of adults, and they averaged $36.0{\pm}3.11$ mm in total length.

• Korean Journal of Ichthyology
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• 제18권1호
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• pp.27-35
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• 2006

During spawning season of female in a Korean oily bitterling, Acheilognathus koreensis, the ventral region near the base of the pectoral fin becomes to be protruded outward of body and enlarged. This ventral process consists of both organs as rectum (vent) and inner ovipositor. The rectum consists of mucosa, lamina propria-submucosa, muscularis, and squamous epithelial layer (peritoneum=serosa) surrounding them. The mucosa contains numerous mucous cells meaning acid mucopolysaccharides in nature. The inner ovipositor is similar to that of the rectum, but the mucosa have no mucous cell, unlike that of the rectum. Whereas, the outer ovipositor has a straight and long tube which are not connected with the ventral process any more. The outer ovipositor was similar to the structure of the inner ovipositor in the ventral process. However, the outer ovipositor has no muscularis, and consists of three layers: mucosa, lamina propria-submucoa, and squamous epithelia. The outer ovipositor without the muscularis seems serves as a tube that eggs discharged from the outer ovipositor allow to send inside mussel, unlike that of the inner ovipositor performing rhythmic contractions of the layers of the muscularies for propelling to the matured oocytes to the outer ovipositor.

• Korean Journal of Environment and Ecology
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• 제31권1호
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• pp.72-80
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• 2017

Fish fauna and community structures in freshwater were analyzed in the streams (12 stations) of the Bogil Island from May to September 2015. Total numbers of the sampled species and genus (9 families) were 21 and 17, respectively. Gobiidae was the most dominant taxa, which accounted for 47.6% (10 species) of the total species, and the relative abundance, based on the number of individuals, was 60.4% (1,157 individuals). Subdominant families were three taxa of Cyprinidae (3 species; 500 ind.), Mugilidae (2 species; 168 ind.) and Mugilidae (2 species; 128 ind.). The dominant species, based on the relative abundance, was Rhynchocypris oxycephalus (20.7%) and the subdominant species were Gymnogobius urotaenia (19.5%), Leucopsarion petersii (17.2%) and Chelon haematocheilus (8.5%). These species were composed of upstream-resident fish as well as migratory fishes, so the streams of the Bogil Island had unique characteristics in the fish compositions. Based on all the species sampled, 9 species (42.9%) were primary freshwater fishes, 11 species (52.4%) were peripheral fishes and 1 species (4.8%) was amphidromous fish. Korean endemic species and exotic species were not found in the streams of Bogil Island. According to the analysis of fish community structure, species richness index and species diversity index were highest (1.831, 1.957) in the Site 8 and lowest in the Site 4. In the meantime, the dominance index was highestin the Site 4 (1.00) and lowest in theSite 8 (0.17).