• Proceedings of the Korean Society of Fisheries Technology Conference
• /
• 2001.05a
• /
• pp.319-321
• /
• 2001

Supply of ntrition-balanced feed is very important for growth of fish, especially for growth of early period of fish. Therefore, most of commercial feeds for larval and juvenile fish are relatively expensive due to high level of the several nutrients to satisfy their requirements for growth. Overfeeding larval fish may increase fish production cost because of larvae feeds high price and deteriorate water quality, eventually reduce growth of fish. (omitted)

• Korean Journal of Ichthyology
• /
• v.22 no.4
• /
• pp.238-248
• /
• 2010

We performed field investigations at six stations in Buk Stream of Goseong-gun, Gangwon-do, Korea, from May to September 2009 to understand the stream's fish fauna and community structure. In the survey, 31 species belonging to 20 families were collected. Dominant species by number was Zacoo koreanus (30.0%), and subdominant species were Pungitius kaibarae (9.4%) and Rhynchocypris steindachneri (9.3%). In biomass, the dominant species was Tribolodon hakonensis (35.5%), and subdominant species were Z. koreanus (22.5%) and Cobitis pacifica (7.5%). Eight Korean endemic fish species and two endangered species (P. kaibarae and Pungitius sinensis) were collected. In addition, four anadromous fish species (T. hakonensis, Oncorhynchus masou masou, O. keta, Gasterosteus aculeatus) and two amphidromus fish species (Plecoglossus altivelis altivelis and Gymnogobius urotaenia) were observed. Interestingly, we verified the existence of several fish species in Buk Stream where they have not lived before. Those species were previously reported to live only in rivers that run into the western and southern sea of Korea. Five of those species (Zacoo koreanus, Z. platypus, Silurus microdorsalis, Liobagrus andersoni and Coreoperca herzi) were reported in Buk Stream in the 1980s. The other species (Pungtungia herzi, Pseudorasbora parva, Squalidus multimaculatus, Misgurnus mizolepis, Koreocobitis rotundicaudata, Silurus asotus and Odontobutis interrupta) have been introduced since the 1990s.

• Development and Reproduction
• /
• v.4 no.1
• /
• pp.79-85
• /
• 2000

This study was made to optimize the conditions needed to produce two types of gynogenetic diploids in the sweet fish, Plecoglossus altivelis. Firstly, ultraviolet (UV) ray doses between 3,000 erg to 14,000 erg/$\textrm{mm}^2$ were tested to inactivate sperm genetically. Based on the appearance of the haploid syndromes in the embryo, a dose of UV ray 6000~7000 erg was required to inactivate sperm genetically. Then, cold shock treatment at 1~2$^{\circ}C$ for 15~30 min were conducted to retain the 2nd polar body in inseminated egg. The best elapsed time before the start of the cold shock was examined between 5~8 min. The experiments in which began 5 min after insemination at 1~2$^{\circ}C$ during 17.5 min gave 21.2％ survival rate and 89.7% normal eyed embryo rate. The gynogenetic diploid produced by suppression of the first cleavage, a considerably high number of heteroploids appeared and high mortality was observed at the metamorphosis stage, so further investigation is needed. The production of gynogenetic diploids were confirmed by GPI isozyme marker. The heterozygous type in Gpi-1 locus was observed in the meiotic-G2N as a result of gene-centromere recombination during meiosis. The heterozygous type was never observed in mitotic-G2N and showed segregation into two homozygous types at Gpi-1 locus.

• Development and Reproduction
• /
• v.4 no.2
• /
• pp.147-152
• /
• 2000

Four clonal lines of ayu, Plecoglossus altivelis, were produced through gynogenesis, mixed before hatching and reared communally. After 10 months, a randomly taken sample was subjected to a standardized shallow water stressor. Hematocrit, hemoglobin, red blood cells count (RBC) and mean corpuscular volume (MCV) were obtained from stressed and non-stressed fish. DNA fingerprinting was used to confirm the clonal nature of the organisms and to identified the clonal line to which each fish belonged. 1 observed significant differences between clona] lines mostly in the hematocrit and MCV measured under no-stress conditions. Such differences are suggested to represent mainly genetic variance, on account of the common environment provided to all the experimental groups. The stress response ratio was lower than expected, mainly due to some unexpectedly high non-stress values. Heritability values (h$^2$) were medium to high for the no-stress measurements (mean 0.238) and very low or zero for the stressed groups'traits (excepting one high value of 0.484). 1 conclude that the use of communally reared clonal lines represents a good tool for the characterization of the physiological traits, thus allowing for their utilization as genetic selection criteria.

• Korean Journal of Ichthyology
• /
• v.30 no.3
• /
• pp.144-154
• /
• 2018

This study investigated the characteristics of fish communities at the Hangang River in Seoul from Jun 2016 to March 2017. During the survey period, there were 56 species of 17 families collected from 5 survey stations. The species that appeared mainly in the brackish water was Coilia nasus, Leiocassis nitidus, Lateolabrax maculata, Repomucenus olidus, Trachidermus fasciatus, Mugil cephalus, Chelon haematocheilus, Synechogobius hastus, Tridentiger bifasciatus and Takifugu obscurus. The migration fish of Anguilla japonica, C. nasus, Plecoglossus altivelis, Hypomesus nipponensis and T. obscurus appeared in this surveyed area. Korean endemic species were 11 species (17.9%) and accounted for a low rate. There were 6 species (10.7%) exotic species including Cyprinus carpio, Carassius cuvieri, Hypophthalmichthys molitrix, Megalobrama amblycephala, Lepomis macrochirus and Micropterus salmoides. The dominant species by stations were Acheilognathus gracilis (St. 1) and Hemibarbus labeo (St. 2, 3, 4, 5). Regarding the tolerance guild according to water quality, there were 3 (7.1%) sensitive species, 24 (42.9%) intermediate species, and 28 (50.0%) tolerance species. Twenty (35.7%) were insectivore species, 18 (32.1%) were omnivore species, 14 (25.0%) were carnivore species, and 4 (7.1%) were herbivore species, indicating the dominating presence of insectivore and omnivore fish species.

• Korean Journal of Ecology and Environment
• /
• v.46 no.2
• /
• pp.192-204
• /
• 2013

Fish community structure and inhabit status of endangered fish species were investigated during April to November 2011 in Baebong Stream, Gangwon do, Korea. The number of fish species inhabiting the upper section (Stations 1~3, 5) was 14 and the stream bottoms were mostly composed of cobbles and boulders (Aa-type). Meanwhile, the number of fish species inhabiting the lower section (Stations 4, 6, 7) was 26 and the stream bottoms were mostly composed of pebbles, cobles and sand (Bb-type). A total of 26 species belonging to ten families were found in the stream during the survey period. The dominant and subdominant species were Rhynchocypris steindachneri (31.1%) and Squalidus multimaculatus (13.3%), respectively, and others such as Pungitius kaibarae (11.0%), Zacco koreanus (7.8%), Misgurnus anguillicaudatus (7.0%), Iksookimia pacifica (5.5%) and Z. platypus (5.3%) were followed in the order. Four species of Squalidus multimaculatus, Z. koreanus, I. pacifica and Liobagrus andersoni were endemic to Korea. And, Lethenteron japonica, L. reissneri, Pungitius sinensis and Cottus hangiongensis were endangered fish species in this stream. Oncorhynchus keta, L. japonica and Tribolodon hakonensis were anadromous species, and Plecoglossus altivelis was an amphidromous species. The similarity index based on species composition and abundance clearly divided the fish community structure of the Baebong Stream into two sections fragmented by a weir installed into the stream. It is necessary to install a fish ways on the weirs for a fish migration and movements.

• Korean Journal of Environment and Ecology
• /
• v.29 no.5
• /
• pp.718-728
• /
• 2015

The fish community and inhabiting status of introduced fish were surveyed at nine stations of Gangeungnamdae stream from September 2013 to May 2014. A total of 36 species of fourteen families were collected from the survey stations and among them, Pungitius sinensis was identified as endangered species. There were nine Korean endemic species (25%) including Coreoleuciscus splendidus. Dominant species were Rhynchocypris steindachneri (St. 1), Zacco koreanus (St. 2, 4, 5, 6), Ladislabia taczanowskii (St. 3)), Zacco platypus (St. 7, 8) and Tribolodon hakonensis (St. 9). Of the 11 introduced species fishes in Gangeungnamdae stream, L. taczanowskii, Pungtungia herzi, Coreoleuciscus splendidus, Squalidus gracilis majimae, Pseudogobio esocinus, Rhynchocypris kumgangensis, Z. platypus, Z. koreanus, Koreocobitis rotundicaudata, Liobagrus andersoni and Coreoperca herzi were released from Han river water zone in Korean. Rapidly expanded population and distribution of introduces fishes were Z. platypus, Z. koreanus, P. herzi and S. gracilis majimae, but L. taczanowskii, C. splendidus, R. kumgangensis were not rapidly expanded population. Settlement but very small population fishes were C. herzi and L. andersoni. When reduced 3% fishes of relative abundance with previous data (1973), R. steindachneri, Orthrias toni, Iksookimia pacifica, Plecoglossus altivelis, P. sinensis and Gymnogobius urotaenia, and R. steindachneri was most reduced from 56.1% to 12.9%.

• Korean Journal of Ecology and Environment
• /
• v.48 no.1
• /
• pp.38-50
• /
• 2015

Appearance patterns of freshwater fish were investigated in the western Demilitarized Zone (DMZ) adjacent areas near Imjin River in Gyeonggi-do, Korea, of 2014. A total of 61 species belonging to 14 families were found in the river during the survey. The dominant and subdominant species were Zacco platypus (Relative abundance, 20.3%) and Zacco koreanus (12.6%), respectively. Other abundant species include Rhinogobius brunneus (9.2%), Pungtungia herzi (4.4%), Acheilognathus yamatsutae (4.4%), and Pseudogobio esocinus (4.0%). Among the residing species, 24 species (39.3%) were endemic to Korea; and 1 species, Carassius cuvieri, was non-indigenous species. Hemibarbus mylodon is a natural monument, and Lethenteron reissneri, Acheilognathus signifer, Pseudopungtungia tenuicorpa, Gobiobotia brevibarba, G. macrocephala, and G. naktongensis are endangered species in Korea. In addition, Anguilla japonica and Plecoglossus altivelis are catadromous and amphidromous species, respectively. Among the investigated sites, the lower part of Sami Stream (St. 5, 6) and Gunnarm-dam region (St. 11, 14) are particularly valuable for the conservation of species diversity, because many fish species (33~42 species) including a natural monument and several endangered species inhabit in these regions.

• Korean Journal of Environment and Ecology
• /
• v.29 no.4
• /
• pp.552-563
• /
• 2015

The characteristics of ichthyofauna and fish community in Lake Goesan were examined from April 2010 to October 2012. During the survey period thirty six species belonging to 11 families were collected. Dominant species by number were Hemibarbus labeo (29.9%) and Zacco platypus (20.0%). In biomass, the dominant species were H. labeo (37.2%) and Carassius auratus (17.9%). Also, fourteen Korean endemic fish species (38.9%) and one endangered species (Acheilognathus signifer) were collected. Further, one catadromous species was observed for stock enhancement (Anguilla japonica), in addition to two land-locked anadromous species (Hypomesus nipponensis, Plecoglossus altivelis) and three exotic species (Cyprinus carpio (Israeli type), C. cuvieri, Micropterus salmoides). According to the length-weight relation of C. auratus and M. salmoides, the b values were 3.13~2.99, 3.11~2.99, showing a declining tendency annually. However, for H. labeo and Z. platypus, the b values were 2.98~3.07, 3.06~3.23 respectively, showing an increasing trend. The slope values for C. auratus and M. salmoides population conditions were controlled by K factor showing a tendency to decrease, but H. labeo and Z. platypus were showing a tendency to gradually increase.

• Korean Journal of Environment and Ecology
• /
• v.34 no.2
• /
• pp.142-156
• /
• 2020

This study surveyed Gyeongan Stream, a tributary of the Han River Drainage System, from April to October 2017 to investigate the characteristics of fish communities. The survey collected 40 species of 11 families from 48 survey stations using kick nets and cast nets. The dominant and subdominant species were Zacco platypus (48.0%) and Rhynchocypris oxycephalus (17.7%), respectively. The next most abundant species were Pungtungia herzi (6.8%), Z. koreanus (5.0%), Carassius auratus (4.3%), Squalidus gracilis majimae (2.7%), and Rhodeus notatus (2.5%). Among the fish collected, 14 species (35.0%) were Korean endemic species, and the exotic species were Micropterus salmoides, Lepomis macrochirus, and Cyprinus carpio (Israeli type). The land-locked species were Plecoglossus altivelis, Rhinogobius brunneus, and Cottus koreanus, while the species sensitive to climate change was C. koreanus. The community analysis showed that the dominance was higher at the uppermost stream station, whereas diversity and abundance tended to be lower at the upstream station and higher toward the downstream station. The community structure was largely divided into rivers (uppermost stream, upstream, and middle-lower stream) and lake. The river health was mostly good (23 stations, 47.9%) and fair (15 stations, 31.3%). Comparison with past surveys showed that 12 species identified in the past surveys did not appear in this survey; nine species appeared for the first time in this survey; and the ecosystem disturbance species - M. salmoides and L. macrochirus - tended to spread more widely gradually.