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메뉴PAHs (Polycyclic Aromatic Hydrocarbons: PAHs) is the hydrophobic inorganic material composed of carbon and hydrogen that is easily adsorbed biological organisms in the ocean. Bivalves is the indicator of environment monitoring because of reflect growth, physiological response of bivalve followed their habitat environment. The aim of research is understand the change of oysters (Crassostrea gigas) physiological response under exposed PAHs concentration for control, 1, 10 and <TEX>$100{\mu}g/L$</TEX>. We investigated induced immune change response for oyster hemocyte and effect of tissue RNA/DNA ratio for mantle, gill and adductor muscle individually. As a result of experiment change of immune response the oyster hemocyte when exposed PAHs showed that viability and adhesion is no significant difference (ANOVA test, p < 0.05). However phagocytosis decreased under the over <TEX>$10{\mu}g/L$</TEX> of PAHs concentration and ROS increased with the increase of PAHs concentration. The change of RNA/DNA ratio is R/D ratio decreased with the increase of PAH concentration in adductor muscle. However gill and mantle showed no change of R/D ratio with PAHs concentration. The oysters when exposed inorganic pollutant that decreased of physiological condition and damaged protein synthesis of adductor muscle.
Mussels have been commonly used in bioassay for quality assessments of environment. Moreover, several standard protocols for the developmental bioassay of bivalves have been proposed. In this study, the EC50 of polycyclic aromatic hydrocarbons (PAHs) was determined using mussel, Mytilus galloprovincialis embryonic developmental bioassay. To determine the sensitivity of M. galloprovincialis, their fertilized eggs were exposed to five PAHs (2-metylnaphthalene, fluorene, dibenzothiophene, phenanthrene, pyrene). The EC50 of 2-metylnaphthalene, fluorene, dibenzothiophene, phenanthrene, and pyrene were 232, 273, 67.9, 43.2, and <TEX>$33.1{\mu}g/L$</TEX>, respectively. The overall sensitivity of M. galloprovincialis in the present developmental bioassay was similar to or more sensitive than that of other marine organisms commonly used in aquatic bioassays. The results of this study could be provide with fundamental data of setting standard for protection of marine life and or can use prediction the aquatic toxicity of PAHs.
A significant production decrease has been witnessed for the Pacific oysters, Crassostrea gigas farmed in the western coastal waters of Korea, presumably by the loss of physiological viability. We evaluated the viability in terms of health indicators, the condition indices and hemocyte apoptosis rates of the oysters inhabiting two representative farming sites, Incheon and Taean each with different environmental variables. In our monthly measurements for the whole year 2013, the indicators were location specific. The condition indices of Incheon were highly variable, 1.67-8.58%, while those of Taean were less, 2.28-5.57%. The condition indices decreased during the spawning seasons, July and September in common. The two oysters exhibited also differed in the apoptotic activities of hemocyte, highly active, 4.03-30.15% for Incheon oysters and less active, 2.87-17.48% for Taean oysters. One thing we could identify was the two measurements were adverse during the critical seasons of spawning, reminiscent of being a useful tool for a health indicator for the oysters. Similar trend was also observed in the time when change in temperature was extreme. The findings in this study are highly indicative of health indicators for the oyster aquaculture.
Single nucleotide polymorphisms (SNPs) are widely acknowledged as the marker of choice for many genetic and genomic applications because they show co-dominant inheritance, are highly abundant across genomes and are suitable for high-throughput genotyping. Here we evaluated the applicability of SNP markers developed from Crassostrea gigas and C. virginica expressed sequence tags (ESTs) in closely related Crassostrea and Ostrea species. A total of 213 putative interspecific level SNPs were identified from re-sequencing data in six amplicons, yielding on average of one interspecific level SNP per seven bp. High polymorphism levels were observed and the high success rate of transferability show that genic EST-derived SNP markers provide an efficient method for rapid marker development and SNP discovery in closely related oyster species. The six EST-SNP markers identified here will provide useful molecular tools for addressing questions in molecular ecology and evolution studies including for stock analysis (pedigree monitoring) in related oyster taxa.
Spermatid differentiations during spermiogenesis and sperm ultrastructures in male Mercenaria stimpsoni were investigated by transmission electron microscopic observations. In the early stage of the spermatid during spermiogenesis, a few granules and a proacrosomal granule, which is formed by the Golgi complex, become a proacrosomal vesicle. Consequently, it becomes an acrosome by way of the process of acrosome formation. The morphologies of the sperm nucleus type and the acrosome of this species have a curved cylindrical type and cap shape, respectively. The spermatozoon is approximately <TEX>$48-51{\mu}m$</TEX> in length including a curved cylinderical sperm nucleus (about <TEX>$4.18{\mu}m$</TEX> long), an acrosome (about <TEX>$0.52{\mu}m$</TEX> in length) and tail flagellum (<TEX>$42-45{\mu}m$</TEX> long). As some ultrastructural characteristics of the acrosomal vesicle, the peripheral parts of two basal rings show electron opaque part (region), while the apex part of the acrosome shows electron lucent part (region). These charateristics of the sperm belong to the family Veneridae in the subclass Heterodonta, unlike a characteristic of the subclass Pteriomorphia showing all part of the acrosome being composed of electron opaque part (region). Therefore, it is easy to distinguish the families or the subclasses by the acrosome structures. Exceptionally, In particular, a cylinder-like nucleus of the sperm is curved (the angle of the nucleus is about <TEX>$80^{\circ}$</TEX>), as seen in some species of Veneridae (range from <TEX>$0^{\circ}$</TEX> to <TEX>$80^{\circ}$</TEX>). The number of mitochondria in the midpiece of the sperm of this species are four, as one of common characteristics appeared in most species except for a few species in Veneridae in the subclass Heterodonta. Cross-sectioned axoneme of the sperm tail flagellum shows a 9+2 structure.
본 연구는 해상가두리에서 2년 동안 수용밀도별로 사육된 북방전복 (Haliotis dicus hannai) 의 성장 및 생존율 조사를 통해 적정 수용밀도를 구명하고 생산성을 향상시키고자 수행 하였다. 수용밀도는 쉘터 단면적 당 점유율로 15, 30, 45, 60 percentage <TEX>$(=per.)/m^2$</TEX>로 설정하여 약 1년을 기준으로 1차 양성기간 (the primary rearing period, PRP), 2차 양성시간 (the second rearing period, SRP) 으로 실시하였다. PRP와 SRP의 1년간 평균 수온은 <TEX>$2^{\circ}$</TEX>의 차이를 보였다. PRP의 북방전복 (평균각장 <TEX>$36.14{\pm}2.28mm$</TEX>) 은 성장에서 각장과 각폭의 절대성장율 (absolute growth rate, ARG), 일간성장율 (daily growth rate, DGR), 특수생장율 (specific growth rate, SGR) 에서 <TEX>$15per./m^2$</TEX> 유의적으로 높았고 (P < 0.05), 생존율은 차이가 없었다. SRP의 북방전복 (평균각장 <TEX>$55.26{\pm}6.93mm$</TEX>) 은 ARG, DGR, SGR에서 <TEX>$45per./m^2$</TEX>제외한 실험구간 유의적 차이는 없었으며, 생존율은 저밀도인 15, <TEX>$30per./m^2$</TEX>는 70% 이상을 보였으나, 고밀도인 45, <TEX>$60per./m^2$</TEX>는 각각 31%, 9%이하였다. 본 실험결과 해상가두리 내에서 각장 3-4 cm 북방전복의 1차 양성기간 적정 수용밀도는 <TEX>$15per./m^2$</TEX> (<TEX>$2.4{\times}2.4m$</TEX>, 1칸 당 750마리) 가 적정하였다. 2차 양성기간 육성용 북방전복 (각장 5-6 cm) 은 경제성을 고려하여 <TEX>$30per./m^2$</TEX>인 양성하는 것이 양식 생산성을 향상시킬 수 있을 것으로 판단된다.
The effects of different stocking densities on the growth and survival rate of the abalone, Haliotis discus hannai, were investigated in marine net cage for two years. Stocking density was set 15, 30, 45 and 60 percentage <TEX>$(=per.)/m^2$</TEX> with share to cross-sectional area per shelter. The primary rearing period (PRP) and the secondary rearing period (SRP) were conducted by a year. One year mean water temperature of PRP and SRS showed the difference about <TEX>$2^{\circ}C$</TEX>. In the growth (initial mean shell length of abalone : <TEX>$36.14{\pm}2.28mm$</TEX>) of PRP, the absolute growth rate (ARG), daily growth rate (DGR) and specific growth rate (SGR) of the <TEX>$15per./m^2$</TEX> were higher than those of density groups (P < 0.05). Survival rates of all density groups were showed no significant difference. In the growth (mean shell length of abalone : <TEX>$55.26{\pm}6.93mm$</TEX>) of SRP, ARG, DGR and SGR of stocking density groups showed no significant difference except for <TEX>$45per./m^2$</TEX> density group. Survival rate in the low-density (15, <TEX>$30per./m^2$</TEX>) was more than 70%, and those of the high-density (45, <TEX>$60per./m^2$</TEX>) were less than 31% and 9%, respectively. These results showed that the appropriate stocking density for <TEX>$15per./m^2$</TEX> was seven hundred fifty number per one net cage (<TEX>$2.4{\times}2.4m$</TEX>), during PRP using 3-4 cm abalone in length. Also for the secondary rearing period, the optimal stocking density (shell length 5-6 cm of abalone) consider with the economical efficiency was determined to be <TEX>$30per./m^2$</TEX>, resulting the productivity improved.
본 연구는 해상가두리의 먹이공급비율에 따른 성장 및 생존율을 조사하고, 실내육상양식의 먹이 공급율과의 비교를 통해 국내 주요 북방전복 양성방법인 해상가두리와 함께 실내 사육 수조의 적정 천연먹이의 공급율을 제안하여 북방전복 생산성 향상을 유도하고자 실시하였다. 먹이공급율은 전복 어체중량을 기준으로 일간공급율 (daily feeding rate, DFR) 5, 10, 15, 20% (5DFR, 10DFR, 15DFR, 20DFR) 를 설정하여, 해상가두리와 실내육상수조에서 2반복으로 13개월간 실시하였다. 해상가두리에서 사육한 전복 (최초 수용 시 평균각장 <TEX>$54.18{\pm}7.39mm$</TEX>) 성장에서 각 장과 각폭의 절대성장율 (absolute growth rate, ARG), 일간 성장율 (daily growth rate, DGR) 및 특수생장율 (specific growth rate, SGR) 과 중량의 증중률 (weight gain, WG), 일간증중률 (daily weight gain, DWG) 및 특수증중률(specific weight gain, SWG), 그리고 생존율에서 20DFR이 유의적으로 낮았다 (P < 0.05). 실내육상수조에서 사육한 전복 (최초 수용 시 평균각장 <TEX>$49.70{\pm}2.28mm$</TEX>) 의 각장, 각폭의 ARG, DGR, SGR과 중량의 WG, DWG, SWG에서는 5DFR, 10DFR이 유의적으로 높았고 (P < 0.05), 생존율은 20DFR이 유의적으로 낮았다 (P < 0.05). 따라서 해상가두리와 실내육상수조 전복양식 자연먹이의 일간 공급율은 성장과 생존율, 그리고 경제적 측면까지 고려하면 어체중량의 5-10%에서 공급해야 한다.
The effect of different feeding rate on the growth and survival rate of the abalone, Haliotis discus hannai, were investigated in marine net cage culture and indoor tank culture. Feeding rate is determined that was fed 5, 10, 15 and 20 percentage to abalone at body weight once daily : 5 daily feeding rate (DFR), 10DFR, 15DFR and 20DFR. After that, it was conducted to reared during thirteen month with two replicates in net-cage culture and indoor tank culture. In the growth performance of reared abalone (initial mean shell length <TEX>$54.18{\pm}7.39mm$</TEX>) in net cage culture, that the absolute growth rate (ARG), daily growth rate (DGR) and specific growth rate (SGR) to the shell length and shell breadth, as well as weight gain (WG), daily weight gain (DWG) and specific weight gain (SWG) to body weight of 20DFR were lower than those of different groups (P < 0.05). Also, survival rates of 20DFR was lower than those of different groups (P < 0.05). In the growth performance of reared abalone (initial mean shell length <TEX>$49.70{\pm}2.28mm$</TEX>) in indoor tank culture, that the ARG, DGR and SGR to the shell length and shell breadth, as well as WG, DWG and SWG to body weight of 5DFR and 10DFR were lower than those of different groups (P < 0.05). And also, survival rates of 20DFR was lower than those of different groups (P < 0.05). Therefore, these results is showed that the daily feeding rate for natural feed in net-cage culture and indoor tank culture should be to supply among 5-10 percents, taking into account growth, survival rate and economical efficiency.
본 연구는 해상가두리와 육상수조의 다양한 중간양성 방법에 대한 성장 및 생존율을 조사하여 육상수조에서의 전복치패 양성의 효율성 증가와 생산성향상을 유도하고자 실시하였다. 해상가두리 (net cage culture, NCC) 실험은 육상수조 사육은 2013년 6월부터 2014년 4월까지 10개월 (300일) 동안 실시하였고, 실험 전복은 2012년에 종묘생산 된 양성 1년생 (각장 평균 22.74-23.67 mm) 을 사용하였다. 육상수조 실험구 설정은 바닥식 양성 (floor culture, FC), 그물 바닥식 양성(net floor culture, NFC), 이중 쉘터 양성 (double shelter culture, DSC) 그리고 육상 가두리 양성 (indoor net cage culture, INCC) 을 각각 2반복구로 설정하여, 수조 당 10,000 마리를 수용하였다. 해상가두리의 월별 각장과 성장률(absolute growth rate of shell length, <TEX>$AGR_{SL}$</TEX>) 은 육상수조 사육방법보다 유의적으로 높았고 (P < 0.05), 육상수조 내 사육방법별 월별 중량변화는 유의적 차이가 없었다. 전복치패 각장의 일간성장률 (daily growth rate of shell length, <TEX>$DGR_{SL}$</TEX>), 특수생장율 (specific growth rate of shell length, <TEX>$SGR_{SL}$</TEX>) 에서도 NCC가 육상수조 실험구보다 유의적으로 높았으며 (P < 0.05), 각폭 성장에서의 성장률 (absolute growth rate of shell breadth, <TEX>$AGR_{SB}$</TEX>), <TEX>$DGR_{SB}$</TEX>, <TEX>$SGR_{SB}$</TEX>에서 NCC가 육상수조 내 실험보다 유의적으로 높았고 (P < 0.05), 육상수조 내 실험구간의 유의적 차이는 없었다. 육상수조 내 실험구에서 측정된 전복체중 성장은 FMW, WG, DWG, SWG에서는 각 실험구별로 유의적 차이가 없으며, 모든 실험구의 생존율은 실험종료 시 까지 55-60%를 유지하였다. 따라서 2 cm이상의 전복치패는 중간양성 시 동일한 밀도, 먹이를 공급한 육상수조 내에서는 차이를 보이지 않았지만, 신선한 먹이가 공급되면서 가두리 주위로 자연먹이가 풍부하게 자랐던 해상가두리가 성장에 유리하게 작용하였던 것으로 판단된다.
This study was conduct to investigate the effect of Intermediate culture types on the growth and survival rate of the abalone, Haliotis discus hannai, in net cage and indoor tank. Intermediate cultures were to determine there that was to setting at marine net cage culture (NCC) in net cage, floor culture (FC), net floor culture (NFC), double shelter culture (DSC) and indoor net cage culture (INCC) in indoor tank, in two replicate. In the growth performance of juvenile abalone reared through intermediate culture, that the absolute growth rate (<TEX>$AGR_{SL}$</TEX>, <TEX>$AGR_{SB}$</TEX>), daily growth rate (<TEX>$DGR_{SL}$</TEX>, <TEX>$DGR_{SB}$</TEX>), and specific growth rate (<TEX>$SGR_{SL}$</TEX>, <TEX>$SGR_{SB}$</TEX>) to the shell length <TEX>$(_{SL})$</TEX> and shell breadth <TEX>$(_{SB})$</TEX> of NCC were higher than those of different groups (P < 0.05). As weight gain (WG), daily weight gain (DWG) and specific weight gain (SWG) to body weight through intermediate culture types in indoor tank was not significant. Also that, survival rate among experimental groups of intermediate culture in indoor tank was not significant. Therefore, these results is showed that should to cultivate for net cage so that intermediate culture of juvenile abalone over 2 cm, accordingly research to effective progress of juvenile abalone intermediate culture in indoor tank be should from various reason as well as feed and rearing condition.
본 연구에서는 한국 남해안 진도에 서식하는 북방전복의 생식소 발달과 생식주기를 조직학적으로 기재하였다. 생식소는 조직학적으로 계절적인 변화를 보였다. 암컷의 비율은 57% (n = 154 / 271) 로 조사되었다. 생식소지수는 암, 수 모두 6월에 최고값 (3.3, 3.9) 을 보였으며, 12월에 최저값 (1.1, 1.1) 을 나타냈다. 비만도와 육중량비는 모두 5월에 최고값을 보였으며, 10월에 최저값을 나타냈다. 생식소지수, 비만도 및 육중량비의 변화는 생식소조직의 계절적 변화와 유사한 양상을 나타냈다. 생식주기는 비활성기 (11월-12월), 초기활성기 (1월-3월), 후기활성기 (3월-4월), 완숙기 5월-6월), 방출 및 퇴화기(7월-10월) 로 구분할 있었다. 2013년 진도에서 북방전복의 주산란기는 7월-8월이었다.
This study histologically describes the gonadal development and reproductive cycle of the abalone, Haliotis discus hannai inhabiting Jindo on the southern seashores of Korea. Gonads displayed histologically definitive seasonal changes. The female ratio (F/F + M) was 57% (n = 154/271). The gonad index (GI) of both males and females was the highest (3.3 and 3.9) in June and was the lowest (1.1 and 1.1) in December. The condition index (CI) and meat weight rate (MWR) were highest in May and lowest in October. The pattern of changes in the GI, CI and MWR were similar to the pattern of seasonal changes in gonadal tissues. The reproductive cycle was divided into an inactive stage (November-December), early active stage (January-March), late active stage (March-April), ripe stage (May-June) and spent and degenerative stage (July-October). The main spawning period of Haliotis discus hannai was July to August at Jindo in 2013.
Phytoplankton species composition and ecological index (diversity, evenness, richness and dominance) were analysed from April 2013 to March 2014 at 10 stations of cupped oyster, Crassostrea gigas culture area in Iwon coast, Korea. Seasonal and positional variation of phytoplankton standing crops, biomass, dominant species and water quality were distinctively different according to occasionally inflow of Iwon dam reservoired water. The composition of phytoplankton species were Bacillariophyceae 98, Dinophycease 22, Chlorophycease 13, Cyanophyceae 8, Silicofalgellate 4, Euglenophyceae 2, Cryptophyceae 1 species. The most dominant species was Bacillariophyceae as 64.0%. The highest biomass of phytoplankton recorded in September as <TEX>$40,910{\times}10^3$</TEX> cell/L at the station 1, near from inland water inflow area. Ecological indices (diversity, richness, evenness, and dominance index), used for structural change of phytoplankton community and water quality (temperature, dissolved oxygen, salinity) showed difference of spatiotemporal property also.
This study was conducted to investigate the impact of sand addition to an intertidal for the development of the Manila clam habitat on benthic community structure. For this, we focused on the spatio-temporal changes in the surface sediment condition and benthic community structure including Manila clam before and after the event. Study site was the lower part of Ojjeom tidal flat in Gonam-myeon, Taean-gun where sand added to on July 2010. We set three stations at each of sand adding area (experimental plot) and non sand-adding area (control plot) and did sampling works ten times from June 2010 to October 2011. Directly after the event, surface sediments changed to very coarse sand, but the state was not maintained over two months because of seasonal sedimentation and finally got back to the original grain sizes in eight months. The number of species and density were temporarily reduced right after the event and polychaetes such as Sternaspis scutata, Ampharete arctica were most negatively affected by the event. However, the number of species and density quickly recovered from the reduction in four to six weeks owing to the recolonization by the existing species and species in the vicinity of the plot. However, despite the recovery of ecological indies, species composition was continuously changed from one to another, thereby community structure stayed unstable condition, especially in some stations with finer sediment in their original condition. After sand addition, density of Manila clam was prominently increased at only one station with coarser sediment in its original condition.
The mass mortalities have been occurring of Korean scallop Patinopecten yessoensis from 1997's to now in Korea east sea. Cages behavior and interference effect (common name; curtain effect) between scallop cages were investigated in culture grounds on the eastern coastal waters of Korea for understand to mechanism of rising about mass mortalities of Korean scallop quickly. The first experiment was carried out in circulating water channel to assess inclination angel from relationship between velocity and cages interval, velocity with culture cages position. An angle of inclination of scallop culture cages were 94.6 to 92.3 degree under a several velocity which were from 0.1 m/s and 131.9 to 118.1 degree under 0.5 m/s with cages interval were 1 m, 94.3 to 91.0 degree under velocity is 0.1 m/s and 133.2 to 122.4 degree under 0.5 m/s with cages interval were 1.5 m and 94.6 to 96.4 degree under velocity is 0.1 m/s and 131.7 to 131.8 under 0.5 m/s with cages interval were 2 m. The second experiment was designed to prove the tank test. Velocities were measured inside and outside of the scallop culture ground at eastern sea of Korea. The velocity of inside of the culture was the slowest as 0.1m/s. In this result, interference between former cage and after cage was occurred.
The biogeography and diversity patterns of the marine bivalve molluscan fauna of the East Sea coast of South Korea are analyzed. The total species richness of the continental Korean bivalve fauna, excluding insular regions (Dok-do and Ullung-do), is 304, and from north to south the species richness of bivalves increases showing a clear gradient: Gangwon, 143 species <TEX>${\rightarrow}$</TEX> Gyeongbuk, 131 <TEX>${\rightarrow}$</TEX> Gyeongnam, 183. A zonal-geographical analysis of the entire fauna shows that the great majority are warm-water mollusks, constituting 77% (subtropical, 37%, tropical-subtropical, 30%, subtropical-boreal, 10%), The number of boreal (low-boreal, widely distributed boreal and circumboreal) species is lower, 19%, whereas boreal-arctic mollusks have only 4%. This demonstrates that the bivalve molluscan fauna of the eastern coast of Korea is subtropical, and has more affinities to the fauna of the East China Sea than to the northern East Sea. Separate analysis by provinces shows the increasing role of warm-water mollusks from north to south. While tropical-subtropical and subtropical species constitute 47% (68 species) in Gangwon, their dominance increases to 71% (93 species) in Gyeongbuk, and to 80% (148 species) in Gyeongnam. The Gyeongnam bivalve fauna is the most diverse in species composition and has the largest number of "endemics" (species known only from this province), 46%. The Gangwon fauna also contains many "endemics", up to 40%, while Gyeongbuk is an intermediate zone with low "endemicity", only at one-fifth of the regional fauna, and has the most species in common among the three provinces.
본 연구는 서해안 새만금 방조제 내만에서 발견된 상괭이의 기생충 감염 사례 보고이다. 상괭이는 수컷으로 연령이 8세로 추정되었다. 기생충은 복강, 두개골 및 폐 등 총 3개 기관에서 3종류가 발견되었다. 복강내 선충은 Crassicauda sp.으로 추정되었다. 두개골내 흡충은 Nasitrema sp., 선충은 Pseudaliids 과에 속하는 폐충의 일종일 것으로 추정되었고 폐충은 폐 조직표본 현미경 검사에서도 발견되었다. 아니사키스 (Anisakis spp.) 는 발견되지 않았다.
Finless porpoise is the one of porpoises in Korean waters that frequently observed in the coastal area. This study reported parasite infection cases of stranded finless porpoise, Neophocaena asiaeorientalis which was stranded on the Saemangeum Dyke on the west coast of Korea 21 May, 2012. The finless porpoise was male, and estimated at 8 years old. Parasites were found in abdominal cavity, skull and lung. The parasites were identified as nematode, trematoda and lungworm. Nematoda in abdominal cavity was Crassicauda sp. Trematoda found in the skull was indentified Nasitrema sp. Lungworm in lung seemed one of genus Pseudaliids. Anisakis spp. has not been found.
We report three new records Korean marine gastropods. The new record species are Hipponix acuta, Lyncina (Ponda) carneola, and Velutina (Velutella) plicatilis cryptospira. As a result, the family Hipponicidae in Korea turned out to be 5 species of 4 genera, Cypraeidae are 14 species of 8 genera, and Velutinidae are 7 species of 3 genera, respectively.
