• Journal of fish pathology
• /
• v.24 no.2
• /
• pp.121-129
• /
• 2011

Aquatic animal raised in hatcheries play an important role in supplying seedling to stock enhancement and seed quality, especially, seed health is the key factor for survival in the field after release and for stocking effectiveness. We have inspected the hatchery-reared seeds of 33 marine species and 12 freshwater species for legally designated diseases in stock enhancement program in 2010. Results showed that abalone was the most abundant as 20.0% in the marine species group and then sea cucumber (15.6%), olive flounder (8.4%), rockfish (6.7%), black sea bream (6.3%) and swimming crab (6.1%) were followed. Crucian carp was the most abundant as 19.4%, and then eel (11.8%), Korean bullhead (10.9%), mandarin fish (10.8%), melanian snail (8.4%), catfish (7.7%) were followed in the freshwater species group. The total number of inspection cases for eight pathogens in this study were 2,105 and disqualification cases were 30 by detection of aquatic animals pathogens such as koi herpesvirus (KHV), red sea bream iridovirus (RSIV), white spot syndrome virus (WSSV) or viral haemorrhagic septicemia virus (VHSV).

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
• /
• v.18 no.2
• /
• pp.104-109
• /
• 2013

The spawning characteristics of Hexagrammos agrammus and Hexagrammos otakii was directly observed in coastal regions of the Yellow Sea and South Sea during the spawning seasons using scuba diving. The territorial male H. agrammus showed different body size, nuptial coloration and nest location compared to those of H. otakii, even though both species caring egg masses were found at the almost same depths. In the West sea, a relatively small guardian H. agrammus male protects 1-2 egg masses laid on a clump of red algae within his territory. The territorial males in red nuptial coloration and their egg masses were well camouflaged in their surroundings. Contrary to H. agammus, a guardian H. otakii male in yellowish nuptial coloration protects 4-8 egg masses in a nest. In addition, their nests were located on the relatively open environments such as discarded fishing nets, rock crevices and a clump of algae. The results of present study shows that even though both of two species belonged to Hexagrammidae, they have different strategies for spawning and protecting their egg masses.

• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.38 no.6
• /
• pp.359-364
• /
• 2005

The distributions of sanitary indicative bacteria and pathogenic bacteria in seawater and four species of farmed fishes, including oliver flounder (Paralichthys olivaceus), black rock fish (Sebastes schlegeli), red sea bream (Pagrus major) and sea bass (Lateolabrax japonicus), collected at fish farms located in the southern coastal area of Korea were investigated from May to October in 2004. The detection rates of fecal coliform and Entirococcus spp. of sanitary indicative bacteria in all samples were $38.9\%$ and $23.8\%$, respectively. The occurrence of fecal coliform was highest of $58.3\%$ in Busan, Geoje and Wando area, followed Yeosu $33.3\%$, Jeju $12.5\%$, Tongyeong $11.1\%$. The occurrence of Enterococcus spp. was highest In Wando area ($45.8\%$), followed by Yeosu ($33.3\%$), Tongyeong ($22.2\%$), Busan ($16.7\%$), Geoje and Jeju ($12.5\%$). The detection rate of fecal coliform was higher than that of Enterococcus spp., except in the Tongyeong area. There was no difference in the detection rate of fecal coliform from May to October, but the detection rate of Enterococcus spp. increased with seasonal warming seawater temperature. Among the pathogenic bacteria, the detection rate of Vibrio alginolyticus ($49.2\%$) in all samples was highest, followed by V. parahaemolyticus ($36.5\%$), Staphylococcus aureus ($6.3\%$), Salmonella sp. ($2.4\%$). However, V cholerae, V. vulnificus and Shigella sp. were not detected in all tested samples. The detection rates of V. parahaemolyticus and V. alginolyticus increased with seasonal warming seawater temperature from May to August.

• Journal of Life Science
• /
• v.24 no.9
• /
• pp.995-1000
• /
• 2014

The studies of marine viruses in terms of viral isolation and detection have been limited due to the high mutation rate and genetic diversity of marine viruses. Of the modern methods currently used to detect marine viruses, serological methods based on enzyme-linked immunosorbent assay (ELISA) are the most common. They depend largely on the quality of the antibodies and on highly purified suitable antigens. Recently, a new experimental system for using viral capsid protein as an antigen has been developed using the yeast surface display (YSD) technique. In the present study, the capsid protein gene of the red-spotted grouper nervous necrosis virus (RGNNV) was expressed and purified via YSD and HA-tagging systems, respectively. Two regions of the RGNNV capsid protein gene, RGNNV1 and RGNNV2, were individually synthesized and subcloned into a yeast expression vector, pCTCON. The expressions of each RGNNV capsid protein in the Saccharomyces cerevisiae strain EBY100 were indirectly detected by flow cytometry with fluorescently labeled antibodies, while recognizing the C-terminal c-myc tags encoded by the display vector. The expressed RGNNV capsid proteins were isolated from the yeast surface through the cleavage of the disulfide bond between the Aga1 and Aga2 proteins after ${\beta}$-mercaptoethanol treatment, and they were directly detected by Western blot using anti-HA antibody. These results indicated that YSD and HA-tagging systems could be applicable to the expressions and purification of recombinant RGNNV capsid proteins.

• Journal of Life Science
• /
• v.16 no.5
• /
• pp.723-728
• /
• 2006

The species of Grateloupia filicina, Grateloupia divaricata in East Sea were investigated taxonmically in order to clarify taxonomic position. The ecological character, external morphology, anatomy of vegetative structure. Blade length are $15{\sim}40\;cm$, erect from discoidal holdfast of $3{\sim}10\;mm$ in diameter. Stipe $1{\sim}2.5\;cm$ long, narrowly cylindrical below, compressed above Grateloupia filicina. Main axis are long and compressed, $3{\sim}7\;mm$ broad in broadest part. Colors are scarlet to light red. Blade length are $10{\sim}25\;cm$, erect from discoidal holdfast of $3{\sim}8\;cm$ in diameter Grateloupia divaricata. Stipe are single and simple $2{\sim}5\;mm$ broad. Thallus composed of cortex and medulla in section ; cortex composed of $9{\sim}10$ layers of anticlinally arranged cortical cell, divided into outer, middle and inner parts. Partial fragments of nuclear 18S rDNAs from the two species of Grateloupia (Rhodophyta) were amplified using the PCR reaction and sequenced to compare their similarity. The partial sequences showed 98.9% similarity each other. Grateloupia filicina has 371 bp sizes and Grateloupia divaricata has 372 bp size. The G+C contents of Grateloupia filicina is 54.3% and Grateloupia divaricata is 53.64%.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.38C no.3
• /
• pp.263-270
• /
• 2013

Recently, the prediction and analysis technology of marine environment are actively being studied since the ocean resources in the world is taken notice. The prediction of marine disaster by automatic collecting marine environment data and analyzing the collected data can contribute to minimized the damages with respect to marine pollution of oil spill and fisheries damage by red tide blooms and marine environment upsets. However the studies of the marine environment monitoring and analysis system are limited in South Korea. In this paper, we study the marine disasters prediction system model to analyze collection marine information of out sea and near sea. This paper proposes the models for the marine disasters prediction system as communication system model, a marine environment data monitoring system model, prediction and analyzing system model, and situations propagation system model. The red tide prediction model and summarizing and analyzing model is proposed for prediction and analyzing system model.

• Animal Systematics, Evolution and Diversity
• /
• v.27 no.3
• /
• pp.220-227
• /
• 2011

The morphology of the two marine urostyloid ciliates, Pseudokeronopsis carnea (Cohn, 1866) and Uroleptopsis citrina Kahl, 1932, in the family Pseudokeronopsidae, collected from the Yellow Sea, and the East Sea, Korea, respectively, were studied using live observation and protargol impregnation. Additionally, the small subunit ribosomal RNA (SSU rRNA) gene was sequenced. These two species are firstly recorded in Korea. The main diagnostic key is as follows. Pseudokeronopsis carnea: body outline elongate-elliptical, brown-reddish or orange-red in colour in vivo; bicorona of 16-24 frontal cirri; one buccal and two frontoterminal cirri; 7-10 transverse cirri; 5-7 dorsal kineties; two types of cortical granules (one orange-red pigment, mainly grouped around cirri and dorsal bristles, arranged in typical rubra-pattern; the other, colourless and blood-cell-shaped, and densely distributed); contractile vacuole in the posterior half of the cell on the left side, usually in posterior 1/3-2/5. Uroleptopsis citrina: body outline elongate-elliptical, lemon-yellow in colour in vivo; two types of cortical granules (one yellow pigment; the other, blood-cell-shaped, densely distributed); bicorona of 12-18 frontal cirri; 2-3 frontoterminal cirri; two midventral rows comprising 26-35 cirri (consisting of anterior paired cirri, non-paired single cirri, and posterior paired cirri); three dorsal kineties. In addition, the SSU rRNA sequences of the two species were compared with public database of these species and consequently, showed high similarity.

• Journal of Korean Society of Coastal and Ocean Engineers
• /
• v.15 no.4
• /
• pp.259-268
• /
• 2003

The damage of water quality like red tide occurs every year inspite of the total load regulation of pollutant inflows from land such as COD, phosphorus and so on around Seto inland sea in Japan. It is attributed to the increase of primary production due to eutrophication. and the rising and settling from the sediment containing nutrient salt. Furthermore, the recent research shows that nutrient salt such as nitrogen and phosphorus, flows into Kii channel from land as well as the Pacific ocean. To investigate the distribution of water quality and flow and residual current in Kitan strait, the field observations were carried out. The field data were obtained a time each season from 1999 to 2002. The results of observations and data of other research institution are used to understand the mechanism of pollution in the strait.

• Korean Journal of Environmental Biology
• /
• v.30 no.1
• /
• pp.1-8
• /
• 2012

To understand growth characteristics of eight dominant red tide species ($Prorocentrum$ $minimum$, $Heterocapsa$ $triquetra$, $Scrippsiella$ $trochoidea$, $Akashiwo$ $sanguinea$, $Chattonella$ $marina$, $Heterosigma$ $akashiwo$, $Amphidinium$ $carterae$ and $Rhodomonas$ $salina$) in the Korean coastal water, the growth rates were examined in relation with the impacts of water temperature and bio-volume. Of these, $P.$ $minimum$, $C.$ $marina$, $H.$ $akashiwo$, $A.$ $carterae$ and $R.$ $salina$ were eurythermal species with relatively high growth rates in a borad ranges (15 to $25^{\circ}C$) of water temperature. On the other hand, the growth rate of $H.$ $triquetra$, $S.$ $trochoidea$ and $A.$ $sanguinea$ were high in relatively mid temperature (optimum: $25^{\circ}C$) condition. In particular, $H.$ $triquetra$ was well adapted in low temperature of 5 to $15^{\circ}C$, implying that the species can survive and grows even at very low temperature. Based on results of our experiment, the growth characterestics of five eurythermal species and three mid temperature species may have dominated in Korean coastal water during summer season and fall season, respectively. Contrastively, the growth characteristics of $H.$ $triquetra$ make a consistently dominant during the cold winter season. In addition, the growth rates of large bio-volume species were lower than those of small bio-volume species, indicates that growth of single cells of several flagellates might be depended on the cells sizes.

• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.15 no.2
• /
• pp.161-170
• /
• 1982

A trial on the seed production of red sea-bream (Chrysophrys major) was made in Jejudo island at the southern end of Korea, from June, 1980 to August, 1981. Histological observation of the gonads indicated that the main spawning season was June to early July in Jejudo area. The newly-hatched fry were fed Brachionus sp. in the later stages Artemia nauplii, Tigriopus sp. and the minced fish flesh were given. Though during the winter season the water temperature in rearing tanks was decreased as low as $9.2^{\circ}C$, continuous feeding to the juveniles was carried out, showing body weight increase. This implies that winter rearing of juveniles in the near-shore facilities is feasible in the vicinity of Seogwipo area, in Jejudo. Feed coefficient of the juveniles (>23.2 g) was $4.16\sim4.77$ when fed the minced fish flesh.