• ALGAE
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• v.34 no.2
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• pp.71-90
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• 2019

A new encrusting red alga was found growing abundantly on glass debris items that drifted ashore along the coasts of Oregon and Washington. These included discarded fluorescent tubes, incandescent light bulbs, capped liquor bottles, and ball-shaped fishing-net floats. Field collections and unialgal cultures of the alga revealed that it consisted of two morphological phases: a young loosely aggregated turf and a mature consolidated mucilaginous crust. The turf phase consisted of a basal layer of globose cells that produced erect, rarely branched, uniseriate to multiseriate filaments up to $500{\mu}m$ long with closely spaced cells lacking pit-plugs. These filaments expanded in size from their bases to their tips and released single cells as spores. At maturity, a second phase of growth occurred that produced a consolidated crust, up to $370{\mu}m$ thick. It consisted of a basal layer of small, tightly appressed ellipsoidal-to-elongate cells that generated a mucilaginous perithallial matrix containing a second type of filament with irregularly spaced cells often undergoing binary division. At the matrix surface, the original filaments continued to grow and release spores but often also eroded. Individual cells, examined using confocal microscopy and SYBR Green staining, were found to contain a central nucleus, a single highly lobed peripheral chloroplast without a pyrenoid, and numerous chloroplast nucleoids. Morphological data from field and culture isolates and molecular data (rbcL, psbA, and SSU) show that this alga is a new genus and species which we name Viator vitreocola, "a traveller on glass."

• Proceedings of the Korean Society of Developmental Biology Conference
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• 2003.10a
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• pp.82-82
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• 2003

Offspring have been produced from somatic cells in a number of species. This biotechnology introduced a new phenomenon in reprogramming and differentiation of somatic cell, namely totipotency. However, birth of oversized calves and perinatal abnormalities such as increased gestation length, lack of spontaneous parturition, higher incidence of dystocia, and reduced perinatal viability of offspring are frequently observed in pregnancies of cloned bovine fetuses. Disturbance of feto-placenta has been proposed as likely causes for abnomal growth. However. Little is known the mechanism responsible for the perinatal problems. Therefore, we focused on gestation length in somatic cell nuclear recipient cows. To solve this issues, placental tissues of control and cloned bovine were obtained by a cesarean section (C-section) before 5 days of paturition. Total RNA from control and cloned bovine placenta was extractd by TRIzol reagent. GeneFishing DEG kits (Seegene) were used to identify differentially expression genes. Total RNA (3 ug) were synthesized by M-MLV reverse transcriptase (200 u/ul) with 10 uM dT-annealing control primer (ACP1) at 42C for 90 min. Then, first-strand cDNA (50 ng) was amplified using the 5 uM arbitary ACP (1-20) and 10 uM dT-ACP2 primers. Some specific expression genes were amplified, Now, we are cloning and sequencing. These finding strongly can be support to solve the problems for parturition delay in nuclear transfer cows, suggest that placenta specific proteins are key indicators for the aberration of gestation and placental function in cows.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.26 no.2
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• pp.133-142
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• 1990

For the purpose of investigation of demersal fisheries resources of the East China Sea, joint research between Hokkaido University and National Fisheries University of Pusan was carried out during the period from November 5 to November 12 in 1989. This joint research is due to continue for the next three years. In this report, the authors analyzed the catch of 24 draughts of trawl operating by the Oshorumaru of the training ship of Hokkaido University in the north area of the East China Sea, in order to hold the present condition of the demersal resources. The specimens collected were composed of 76 species of fishes, 6 of mollusca and 7 of crustacea. And the main species of the large catch were Raja kenojei, Zeus faber, Miichthys miiuy, Collichthys lucidus, Dentex tumifrons, Carangoides caeruleopinnatus, Trachurus japonicus, Parastromateus niger, Trichiurus leptulus, Scomberomorus niphonius, Pampus argenteus, Pampus echinogaster, Psenopsis anonala, Liparis tanakai, Thammaconus modestus, Tadarodes pacificus, Loligo edulis, and Portunus trituberculatus. Especially, Trichiurus leptulus, Pampus agrenteus and Thammaconus modestus had different modes of classes of body size individually, with changing of fishing ground. But, Tadarodes pacificus, Loligo edulis and Portunus trituberculatus were caught the maxed sizes of body individually in the same ground.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.17 no.1
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• pp.15-23
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• 1984

Difference of the entering and the escaping behaviour of shrimp(Palaemon pacificus) to the model traps were observed in accordance with netting materials, baits, type of traps and slope of flapper, and gathering responses were also investigated on the odour of bait extracts in the aquarium as the preliminary test. In order to investigate the difference in catch according to type and structure of traps those designated from A to E were made of iron frames and nettings. The type A was a conical shape with two entrances at its both sides and the others were square piller shape with one entrance at their upper surface(type B) or two entrance at their both ends(type C, D and E). However th type D and E were connected with flapper and the thye E was made by attaching iron frames of same height under the type D. The traps were prepared 10 each and so a total of 50 traps were used in the experiment at sea. The main species caught was Charybdis japonica, but Astroconger myriaster was also caught fairly. The catches of these species were significant in difference between the types of traps. That is, Charybdis japonica was caught more in type A, C and D than others and less in type B and E, and Astroconger myriaster was caught more in type A and D and less in type B and E. However the catch of Astroconger myriaster in type C, even if less than that in type A showed no significant difference with the other traps. The total catch of Charybdis japonica and Astroconger myriaster was almost same in order with the catch of Charybdis japonica. The type B and E seemed to be difficult in entering of fishes into them. However, the type A and C seemed to be easy not only in entering, but also in escaping. Especially, the type C showed more escaping. On the other hand, the type D seemed to be not so easy in entering of fishes as type A and C, but very difficult in escaping. Consequently, the escaping of fishes from the traps seemed to be more difficult in conical traps than any other traps. The catches might be influenced by the bait with bag compare to without bag and also the immersed time of traps into water for fishing.

• Parasites, Hosts and Diseases
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• v.22 no.1
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• pp.78-84
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• 1984

In order to determine the infestation patterns for metacercaria of digenetic trematodes, several kinds of fresh-water and brackish-water fish were caught in River Hyungsan, Kyungpook Province, Korea and examined from March to October in 1983. They were collected by netting, fishing with rod and line, or using the bait of crushed oil cake in transparent plastic bowls, and were dissected into the flesh, scales and 6ns with tail, and then examined for the presence and infestation density of larval trematodes. Of the 11 kinds of fish examined, the encysted larvae of Exorchis oviformis were found all of them, Metagonimus yokogawai from 9 kinds, Cyathocotyle orientalis, Metacercaria hasegawai and Metorchis orientalis from 6 kinds, alld Clonorchis sinensis from 4 Kinds in the present study. In the intensity of infestation with Clonorchis sinensis, the Korean shiner, Gnathopogon atromaculatus Nichols et Pope, was the most heavily infected species, the average number of metacercariae per grata of fish flesh being 45.5, followed by the striped shiner, Puntungia hirxi Ibersenstein 11.6, and Southern top-Inouthed minnow, Pseudorasbora larva (Temminck et Shlegel) , 9.7. The intensity of infestation with the iwetagonimus larvae in 8 species of fresh-water fish was relatively low, and the average number per gram of flesh varied from 0.23 to 9.1. In comparison, the brackish-water fish were more heavily infected and the mean number of cysts per gram of flesh in the sweetfish, Plecoglossus altiwelis, was 32.9. The results of this study generally indicate that Clonorchis sinensis and Metagcnimus yckogawai infection may occur by consuming raw fresh-water fish caught in the river Hyungpook, Kyungpook Province, Korea.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.31 no.1
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• pp.63-73
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• 1995

A remote telesounder system was manufactured to investigate the behavior and distribution characteristics of fish and was tested to verify its performance and effects int he set net fishing ground located off the Namhae island, Oct. 26~27, 1994. The activity pattern of fish was observed at the buoy station installed in a set net and it was also analyzed simultaneously at the remote base station on land located at distance of about 1.5km away from the buoy station. Several findings at both the buoy station and the base station were as follows: The images of color display monitor at the base station on land were very well coincident with the records observed at the buoy station. The lower part of slope net and bagnet fluctuated irregularly, and its variations were about 3.6m and 6.0m, respectively. In the daytime, the fish school entered playground, passed slope net with 5~7m depth, moved dispersedly at night and at twilight the entrance was rare. In the bagnet, in the daytime the fish school swam in the layer of 8m in depth, at night the fishes dispersed in the entire layer and at twilight they formed dense school. The fishes caught by the set net were about 500kg with 20 species. Anchovy was the most dominant species. In conclusion, the remote telesounder was a convenient and powerful system for investigating the distribution pattern and the swimming behavior of fish entering in set net.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.42 no.2
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• pp.69-77
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• 2006

The aim of this study was to develope a fishing technology for fisheries management for improving the survival rate of young fishes escaped from trawl net. Sea experiments were carried out to investigate the survival rate of the fishes in off Geomun island and Korean southern sea. Cover-net fish cage was designed and manufactured to collect fishes escaped from COD(codend) and TED(trawl escapement device). Fish cage was installed in a shallow site where scuba diver can observe the surviving fishes after separating the cage from trawl net. Most of fishes except horse mackerel(Trachurus japonicus) and mackerel(Scomber japonicus) could escaped through TED(bar space 35mm) easier than COD(mesh size 54mm). Especially, escapement rate of redlip croaker(Pseudosciaena polyactis) escaped from TED was the highest as 73.9%. Survival rate of horse mackerel(Trachurus japonicus) escaped from TED was 85.5% at the point of 96 hours over, while the survival rate for COD showed a rapid decrease according to the time elapse as 85.0% at the point of 24 hours, 76.4% for 48 hours, 62.7% for 72 hours and 56.1% for 96 hours. Over 90% of red seabream(Pagrus major) and rock bream(Oplegnathus fasciatus) escaped from TED were survived 96 hours over and the survival rate of those fishes were excellent compared with the other fish species. All korean pomfret(Pampus echinogaster) escaped from both COD and TED were died within 48 hours. Most of redlip croaker(Pseudosciaena polyactis) were also died within 12 hours because of the weak physiological characteristics by water pressure change. Survival rate of fishes like as horse mackerel(Trachurus japonicus) having hard skin was high while it was low for the fishes like as squid(Todarodes pacificus) and hair-tail(Trichiurus lepturus) having soft skin. We could know that there were big differences in the survival rate offish species escaped from trawl net.

• Journal of the Korean Institute of Landscape Architecture
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• v.37 no.1
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• pp.50-64
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• 2009

The freshwater lakes located at the fringe of urban cities are a habitat for diverse organisms. However, they are facing severe danger of environment deterioration and water pollution caused by reckless development of the area. In this study, an ecological management plan was suggested to promote the biodiversity through appointing management area based on the research and analysis data of flora and fauna as well as maintain biodiversity and harmonize utilization of freshwater lakes such as Duryang Reservoir at Sacheon, Gyeongsangnam-do. Base on the data of ecological research and analysis, this study conducted research on biotope assessment, wild life habitat assessment and presence of protected species. As a result, the ecosystem conservation area including multi-layer structured natural forests, waterside and wetland that are home to various species and the edge area with high habitat diversity were recognized as highly preservable regions. Management areas were ecologically disturbed region, highly polluted commercial district and damaged waterside caused by fishing. Proactive management must be implemented through vegetation management such as vegetation transition and shrub planting as well as establishing pollutant management system. The deterioration of waterside and forest vegetation of freshwater lake has a direct influence on biodiversity and water quality. Therefore, the conservation area and development area should be totally separated from each other, and the development area must be restored and managed strictly.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.14 no.2
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• pp.59-65
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• 1981

The purpose of the present study is to find the light intensity which induces maximum gathering rate and to observe the variation of the gathering rate both in daytime and at night by rising two species of commercial fishes: gray rock cod. Sebastes inermis (Cuvier et Valenciennes) and cat shark, Scyliorhinus torazame (Tanaka). An experimental tank $(360L\;{\times}\;50W\;{\times}\;55H\;cm)$ was set up in a dark room. An illumination system was attached to one end of the tank to control horizontal light intensity. Six artificial light sources were prepared by combination of two light bulbs (5W, 150W) and seven filters. During the experiment water depth was maintained 50 cm level in the tank. The tank was marked into six longitudinal sections each being 60 cm long to observe the distribution of fish. The fish were acclimatized in dark condition for 40 minutes prior to the main experiment. Upon turning on the light, the number of fish in each section was counted 40 times every 30 seconds, and the gathering rates were obtain from the average number of fish in each section. The light intensity inducing maximum gathering rate is as follows: gray rock cod: 16.6 lux (10.6-24.5 lux) (day), 0.7 lux (0.5-1.1 lux) (night), cat shark: 1.9 lux (1.2-2.9 lux) (day), 16.6 lux(10.6-24.5lux) (night). Trend of the gathering rate in illumination time revealed different results in two fish species. Gathering rate of gray rock cod did not show any definite pattern but fluctuated irregularly. The gathering rate was some fluctuating at night. However, that of cat shark was almost constant and did not show any distinctive difference between day and night.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.46 no.5
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• pp.598-606
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• 2013

The blackfin flounder Glyptocephalus stelleri is a commercially important species in the East Sea of Korea, but its catches and biomass have decreased gradually in recent years. This study estimated the optimal catch (acceptable biological catch, ABC) for the effective management of this species by estimating population ecology parameters and the stock biomass of blackfin flounder in the East Sea of Korea. The estimated instantaneous coefficient of total mortality (Z) of blackfin flounder was 1.0542/year, the survival rate (S) was 0.3485, and the instantaneous coefficient of natural mortality (M) was 0.3637/year. From the values of S and M, the instantaneous coefficient of fishing mortality (F) was calculated to be 0.6905/year. The age at first capture was 1.304 years, and the total length was 11.5 cm at that time. On the basis of these parameters, the annual biomass was estimated by a biomass-based cohort analysis using annual catch data in weight by year for 1991-2012 in the East Sea of Korea. The annual biomass peaked in 1997 at about 12,800 mt and then subsequently declined continuously to a level of 10,500 mt in 2004 and to 9,800 mt in 2011 and 2012. The maximum sustainable yield and $F_{0.1}$ were estimated as 3,547 mt and 0.3595/year, respectively. Using these estimations, the ABC was estimated to be 3,571 mt in tier 5, 3,397 mt in tier 4, and 2,622 mt in tier 3.