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REFERENCE LINKING PLATFORM OF KOREA S&T JOURNALS
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Korean Journal of Fisheries and Aquatic Sciences
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Journal DOI :
The Korean Society of Fisheries and Aquatic Science
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Volume & Issues
Volume 48, Issue 6 - Dec 2015
Volume 48, Issue 5 - Oct 2015
Volume 48, Issue 4 - Aug 2015
Volume 48, Issue 3 - Jun 2015
Volume 48, Issue 2 - Apr 2015
Volume 48, Issue 1 - Feb 2015
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Properties and Oxidation Stability of Fish Oil Capsules Manufactured with Calcium Alginate Gels
Yun, Young-Soo ; Jang, Su-Ji ; Kim, Hong-Deok ; Kim, Seon-Bong ;
Korean Journal of Fisheries and Aquatic Sciences, volume 48, issue 5, 2015, Pages 589~595
DOI : 10.5657/KFAS.2015.0589
Alginates are used to encapsulate various materials, including food, cosmetics, and pharmaceuticals. This study examined the properties and oxidation stability of fish oil capsules manufactured with calcium alginate gels. The fish oil capsules were manufactured by dropping sodium alginate solution and fish oil into a calcium chloride solution through nozzles. The membrane thickness, sphericity, rupture strength and deformation depth of the fish oil capsules were determined. The peroxide value of the fish oil was assayed to determine the oxidation stability of the capsules. The capsules measured approximately 3 mm with a membrane thickness of 90 μm independent of the amount of fish oil added. As the amount of fish oil encapsulated increased, the sphericity, rupture strength and deformation depth of the capsules decreased. The encapsulation efficiency increased until the amount of fish oil was 30%. The oxidation stability of fish oil in capsules was dependent on the type of nozzle, e.g., the oxidation stability of fish oil in capsules made using a double nozzle was greater than with a single nozzle. These results should lead to industrial application of fish oils including eicosapentaenoic (EPA) and docosahexaenoic (DHA) acids, as nutraceuticals.
Effects of Adding Oyster Crassostrea gigas Shell Powder on the Food Quality of Chinese Cabbage Kimchi
Do, Hyoung-Hun ; Kim, Ji-Hoon ; Han, Hae-Na ; Kim, Song-Hee ; Kim, Gab-Jin ; Eom, Sung-Hwan ; Kim, Young-Mog ;
Korean Journal of Fisheries and Aquatic Sciences, volume 48, issue 5, 2015, Pages 596~603
DOI : 10.5657/KFAS.2015.0596
This study investigated the effects of adding oyster shell powder (OSP) from Crassostrea gigas on the food quality of Chinese cabbage Kimchi (CCK). We monitored the changes in microbial levels, pH, acidity and sensory evaluation during the fermentation of CCK treated with various contents of OSP. The microbial assay showed that adding OSP to CCK inhibited the growth of viable cells, total coliforms, and lactic acid bacteria, with the greatest growth inhibition against lactic acid bacteria over the fermentation period. After fermentation for 18 days, the lactic acid bacterial counts in CCK treated with OSP (0.3%, 0.5% and 1%) were at least 1 log CFU/g lower than those of control CCK. In addition, the pH and acidity of CCK treated with OSP were lower than in control CCK over the fermentation period. The overall sensory evaluation of CCK with 0.3% OSP was better than that of control CCK after fermentation for 24 days. In conclusion, OSP treatment, especially 0.3% OSP, enhances the food quality and extends the self-life of CCK, while minimizing the detrimental effects on its sensory characteristics.
Sanitary Characterization of Commercial Boiled-dried Pacific Herring Clupea pallasi and Boiled-dried Anchovy Engraulis japonicus and Proposal of Quality Standards
Kang, Sang In ; Lee, Su Gwang ; Kim, Yong Jung ; Kim, Min Joo ; Park, Sun Young ; Heu, Min-Soo ; Kim, Jin-Soo ;
Korean Journal of Fisheries and Aquatic Sciences, volume 48, issue 5, 2015, Pages 604~613
DOI : 10.5657/KFAS.2015.0604
The objective of this study was to estimate the food quality of commercial boiled-dried Pacific herring Clupea pallasi as a substitute for boiled-dried anchovy. Standards for controlling quality of boiled-dried Pacific herring were suggested based on international (US FDA and CODEX) and domestic (Korean FDA, Standards on Quality of Seafood and Seafood Products, KS) standards for boiled-dried anchovy. The standards included requirements for moisture [less than 30% (less than 35 in very tiny sizes)], water activity (less than 0.85), salinity (less than 10%), water-phase salt (less than 20%), acid-insoluble ash (less than 1.5%), yeast and mold (fewer than 1.0×10
CFU/g), and different size and breakage (less than 5%). Based on the standards suggested, commercial boiled-dried Pacific herring passed nine levels (all levels) in water activity, acid-insoluble ash, mold and yeast concentrations; seven levels (L-1, 2, 3, 4, M-1, 2, S) in water-phase salt, and three levels (L-1, 3, 4) in the ratio of different size and breakage categories. These results suggest that the quality of commercial boiled-dried Pacific herring is similar to that of commercial boiled-dried anchovy.
Sensory and Lipid Characterizations of Boiled-dried Pacific Herring Clupea pallasii as a Substitute for Boiled-dried Anchovies Engraulis japonicus
Lee, Su Gwang ; Kim, Yong Jung ; Heu, Min-Soo ; Kim, Jin-Soo ;
Korean Journal of Fisheries and Aquatic Sciences, volume 48, issue 5, 2015, Pages 614~620
DOI : 10.5657/KFAS.2015.0614
The objective of this study was to investigate sensory and lipid characterizations of boiled-dried Pacific herring Clupea pallasii (PH) as a substitute for boiled-dried anchovies (A). The crude lipid content of commercial boiled-dried PH ranged from 1.3 to 5.1%, which was similar to that of commercial boiled-dried A (2.2-5.1%). The peroxide values (POVs) of commercial boiled-dried PH ranged from 20.5 to 129.1 meq/kg. The POVs of commercial boiled-dried PH suggest that boiled-dried PA of high quality should be controlled by a POV standard similar to that of boiled-dried A. The trichloroacetic acid soluble-nitrogen (TCA soluble-N) content of commercial boiled-dried PH ranged from 495.7 to 998.6 mg/100 g, which was high compared to that of commercial boiled-dried A (372.6-690.0 mg/100 g). Volatile basic nitrogen (VBN) content of commercial boiled-dried PH ranged from 8.4 to 28.1 mg/100 g, which was low compared to that of commercial boiled-dried A (16.8-33.0 mg/100 g). Results from the lipid, POV, TCA-soluble-N, and VBN content analyses suggest that boiled-dried PH could be used as a substitute for boiled-dried A.
Mercury Contamination and Risk Evaluation in Commonly Consumed Fishes as Affected by Habitat
Jo, Mi Ra ; Kim, Ki Hyun ; Jo, Mun Rae ; Kwon, Ji Young ; Son, Kwang Tae ; Lee, Hee Jung ; Kim, Ji Hoe ; Lee, Tae Seek ; Kang, Sang In ; Kim, Jin-Soo ;
Korean Journal of Fisheries and Aquatic Sciences, volume 48, issue 5, 2015, Pages 621~630
DOI : 10.5657/KFAS.2015.0621
This study investigated the concentration of total mercury in 17 species of commonly consumed fishes and assessed the risk to human health from provisional tolerable weekly intakes PTWI% as affected by migratory characterization, such as migration and vagility. The measured mean concentrations of total mercury in these 17 species of commonly consumed fishes suggest that mean concentrations of total mercury in 10 species of migratory fishes (largehead hairtail, chub mackerel, Pacific saury, skipjack tuna, Pacific cod, anchovy, Alaska pollack, brown croaker, Japanese Spanish mackerel, yellow croaker and Pacific herring) were low compared to those in 7 species of demersal fishes (red stingray, brown sole, bastard halibut, conger eel, blackmouth angler, rockfish and filefish). Based on the mean concentrations, the PTWI% of total mercury among commonly consumed migratory fishes was 3.393%, which was higher than that of commonly consumed demersal fishes (2.710%).
Changes in the Quality Characteristics of Semi-dried Small Squid Idiosepius paradoxus during Refrigerated Storage
Jung, Bok- Mi ; Ahn, Chang- Bum ; Kim, Hyung- Rak ;
Korean Journal of Fisheries and Aquatic Sciences, volume 48, issue 5, 2015, Pages 631~638
DOI : 10.5657/KFAS.2015.0631
This study evaluated the quality characteristics of semi-dried small squid Idiosepius paradoxus treated with grapefruit Citrus paradisi seed extract (GSE) during refrigerated storage for 6 months. The moisture content and water activity decreased significantly in both control and GSE-treated groups with increasing storage time, but there was no significant difference between groups. During storage, the degree of water activity reduction was lower in the GSE-treated group than in the control. The pH change was similar in both groups during storage. The thiobarbituric acid reactive substances (TBARS) value of the GSE-treated group was lower than that of the control until 4 months of storage, and was subsequently higher than in the control group. The Hunter color L value did not differ significantly during storage between groups, whereas the a and b values decreased significantly (P<0.05) in both groups with increasing storage time. The hardness value of the semi-dried small squid increased with storage time, but there was no statistical difference between GSE treatment and control. There were more viable cells in the control group than the GSE-treated group after 5 months of storage. According to the sensory evaluation, neither the taste, color, odor, nor texture differed statistically during storage between groups, while overall acceptability was significantly lower in the GSE-treated group than the control after 6 months of storage.
Genetic Characterization of the Urease Gene Cluster in Photobacterium sp. Strain HA-2 Isolated from Seawater
Kim, Tae Ok ; Park, Kwon Sam ;
Korean Journal of Fisheries and Aquatic Sciences, volume 48, issue 5, 2015, Pages 639~643
DOI : 10.5657/KFAS.2015.0639
In this study, we cloned and sequenced the 15,204-bp DNA region containing the gene cluster for urease production from the chromosome of the environmental Photobacterium sp. strain HA-2. We identified 15 open reading frames (ORFs) and the G+C content was 40.3%. The urease gene cluster of Photobacterium sp. strain HA-2 consisted of seven genes, namely, ureDABCEF and ureG. There were five ORFs of urease genes in the opposite direction, which were homologous to the nickel transport operons (nik) of Vibrio parahaemolyticus and Escherichia coli. The genetic organization and sequences of the urease genes of Photobacterium sp. strain HA-2 resembled those found in Vibrio fischeri and V. parahaemolyticus.
Quality Changes and Processing of Fermented Red Snow Crab Chionoecetes japonicus Sauce using Aspergillus kawachii koji
Kim, Byoung-Mok ; Lim, Ji-Hoon ; Jung, Jee-Hee ; Jung, Min-Jeong ; Kim, Dong-Soo ; Lee, Kwang-Pyo ; Jun, Joon-Young ; Jeong, In-Hak ;
Korean Journal of Fisheries and Aquatic Sciences, volume 48, issue 5, 2015, Pages 644~654
DOI : 10.5657/KFAS.2015.0644
This study investigated changes in the quality of fermented red snow crab Chionoecetes japonicus sauce with or without Aspergillus kawachii koji and added salt. Samples were divided into four groups depending on whether koji was added and the amount of salt: RC15, 15% added salt, no koji; RC20, 20% added salt, no koji; RK15, 15% salt plus 10% koji; and RK20, 20% salt plus 10% koji. The samples were fermented at 20±2℃ for 4 months. During the fermentation period, the moisture contents of the four types of sauce decreased while the crude ash and protein contents increased. The pH of the RK groups decreased and was lower than in the RC groups. The acidity of the RK groups increased and was higher than in the RC groups. Both the total nitrogen (TN) and amino nitrogen (AN) levels increased continuously and were higher in the RK groups than in the RC groups. The volatile basic nitrogen (VBN) content increased rapidly and was higher in the RC groups than in the RK groups. The color did not differ significantly among the four groups. The viable cell counts in the four groups increased and no coliforms were detected. The total free amino acid and glutamic acid contents were highest in the RK15 group and the main amino acids in RK15 were aspartic acid, glutamic acid, alanine, leucine, phenylalanine, and lysine. Overall acceptance was significantly higher for the RK groups than the RC groups and RK15 ranked highest among the four sauces. These results suggest that Aspergillus kawachii koji is beneficial for processing fish sauce made using red snow crab.
Effects of Freezing Storage Temperature and Thawing Time on Separation of Leg Meat from Red Snow Crab Chionoecetes japonicus
Kim, Byoung-Mok ; Jeong, Jee-Hee ; Jung, Min-Jeong ; Kim, Jong-Chan ; Jun, Ki-Hong ; Kim, Dong-Soo ; Lee, Kwang-Pyo ; Jun, Joon-Young ; Jeong, In-Hak ;
Korean Journal of Fisheries and Aquatic Sciences, volume 48, issue 5, 2015, Pages 655~660
DOI : 10.5657/KFAS.2015.0655
This study investigated the effects of freezing storage temperature and thawing time on the separation of leg meat of the red snow crab Chionoecetes japonicus. Crabs were stored at -20, -30, -40, or -50°C for 2 days and thawed for either 5, 10, 20, 30, or 40 seconds. While thawing, there were no significant differences in pH or acidity among the experimental groups, while the volatile basic nitrogen content increased continuously. The redness of samples stored at -20°C was higher than that of the other groups. The overall acceptance of samples stored at -20°C was also the best. These results demonstrate that no-heating methods may be useful for separating red snow crab leg meat.
Bactericidal Efficacy of a Monopersulfate Compound against Vibrio harveyi and Toxicity to Litopenaeus vannamei
Min, Jeong-Ran ; Na, Kwang ; Chong, HyunJin ; Jeong, Sang-Hee ;
Korean Journal of Fisheries and Aquatic Sciences, volume 48, issue 5, 2015, Pages 661~667
DOI : 10.5657/KFAS.2015.0661
Vibrio harveyi is one of the most serious pathogens causing vibriosis in larval and grow-out shrimp culture. This study was performed to investigate the bactericidal effect of a monopersulfate compound against V. harveyi and its toxicity in Litopenaeus vannamei. The monopersulfate compound was prepared at 0, 0.15, 0.3, 0.6, 1.2, and 2.4 ppm for the bactericidal efficacy study, and then V. harveyi was added at a rate of 1×10
CFU/mL. Subsequently, five shrimps/dose were added to the water bath. The other groups of shrimp were exposed to monopersulfate, but not to the bacterium. None of the shrimps exposed to any of the monopersulfate treatment doses without bacteria died, and no changes in their movement were detected for 7 days. However, shrimps exposed to bacteria without monopersulfate showed decreased movement and lethargy, but no death. The total number of other bacteria and V. harveyi at the different concentrations decreased significantly by 4-6 log values compared to that in the bacterial control group. The monopersulfate compound completely inhibited V. harveyi growth beginning 1 h after exposure to 2.4 ppm. These results show that the monopersulfate compound is an efficient disinfectant against naturally occurring marine bacteria and V. harveyi without being toxic to shrimp.
Volatile Flavor Constituents of Cooked Oyster Sauce Prepared from Individually Quick-frozen Oyster Crassostrea gigas Extract
Hwang, Young-Suk ; Kim, Sang-Hyun ; Shin, Tai-Sun ; Cho, Jun-Hyun ; Lee, In-Seok ; Oh, Kwang-Soo ;
Korean Journal of Fisheries and Aquatic Sciences, volume 48, issue 5, 2015, Pages 668~673
DOI : 10.5657/KFAS.2015.0668
The pacific oyster Crassostrea gigas has a desirable taste and flavor that differs from those of other fish and shellfish. In order to develop a high value-added product from individually quick-frozen oyster extract (IQFOE), we prepared an oyster sauce from IQFOE and characterized its volatile compounds using vacuum simultaneous steam distillationsolvent extraction / gas chromatography / mass spectrometry. The moisture, crude protein, crude ash, salinity, pH and volatile basic nitrogen contents of the oyster sauce were 60.6%, 8.2%, 9.2%, 9.3%, 5.7 and 21.0 mg/100 g, respectively. Seventy-six volatile compounds were detected in the cooked odor of the oyster sauce. These volatile compounds included 14 esters, including ethyl acetate, 13 nitrogen- containing compounds, including 2,4,6-trimethyl pyridine, 13 acids, including hexadecanoic acid, 12 alcohols, including ethyl alcohol and 6-methyl heptanol, 6 alkanes, 5 aldehydes, including benzaldehyde, 5 ketones, including 1-(2-furanyl)-ethanone, 4 furans, including 2-furancarboxaldehyde and 2-furanmethanol, 3 aromatic compounds, including d-limonene, and 1 miscellaneous compound. Esters, acids and nitrogen-containing compounds, and alcohols were the most abundant compounds in the odor of the cooked oyster sauce, with some aldehydes, ketones, and furans.
Physiochemical Characteristics of Rapidly Processed Salt-fermented Sandfish Arctoscopus japoncus Sauce with Thermophilic bacillus
Nam, Ki Ho ; Jang, Mi Soon ; Park, Hee Yeon ; Kwak, Won Ju ;
Korean Journal of Fisheries and Aquatic Sciences, volume 48, issue 5, 2015, Pages 674~680
DOI : 10.5657/KFAS.2015.0674
This study was conducted to characterize the rapidly processed salt-fermented sandfish sauce added Bacillus coagurance KM-1 (RSSS) and commercial salt-fermented sandfish sauce (CSSS 1, 2). Contents of total nitrogen and amino nitrogen were higher in CSSS 1,2 than in RSSS (P<0.05). Total free amino acid contents of RSSS and CSSS 1,2 were 1,121.2±100 mg/100 g, 1,553.6±98.2 mg/100 g and 1,507.3±99.8 mg/100 g. Major free amino acid of RSSS was glutamic acid (194.4±17.3 mg/100 g), alanine (140.8±12.6 mg/100 g), lysine (135.1±12.1 mg/100 g), leucine (109.8±9.8 mg/100 g), aspartic acid (103.0±9.2 mg/100 g), valine (73.5±6.6 mg/100 g) in ordor. The samples were caused by their composition of the free amino acids rations, in which were umami, sweet and bitter taste in the salt-fermented sandfish sauce during fermentation. The Na was the largest mineral followed by K, Mg, P, Ca in the samples (P<0.05). Sensory evaluation result of samples, CSSS 1 was the highest than the others in overall acceptance.
Optimum Feeding Rates for Growing and Sub-adult Olive Flounder Paralichthys olivaceus Fed Practical Extruded Pellets at High Water Temperature
Kim, Sung-Sam ; Kim, Kang-Woong ; Kim, Kyoung-Duck ; Lee, Bong-Joo ; Han, Hyon-Sob ; Lee, Kyeong-Jun ;
Korean Journal of Fisheries and Aquatic Sciences, volume 48, issue 5, 2015, Pages 681~687
DOI : 10.5657/KFAS.2015.0681
We investigated the effects of feeding rate on the growth performance of growing and sub-adult olive flounder Paralichthys olivaceus, and the optimum feeding rate at high water temperature (25-31℃). In experiment I, two replicated groups of fish (113 g) were fed a commercial diet (CD) at rates of 0, 0.7, 1.2, 1.7, 2.2, and 2.4% (satiation) body weight (BW) per day for 4 weeks. In experiment II, two replicated groups of fish (313 g) were fed a CD feeding rates of 0, 0.3, 0.5, 0.7, 0.9, and 1.0% (satiation) BW per day for 4 weeks. In experiment I, the weight gain (WG) and specific growth rate (SGR) of fish fed at 0.7 and 0.9% BW per day was significantly higher than that of unfed fish (0%) and fish fed at 0.3, 0.5, and 1.0% (satiation) BW per day. In experiment II, the WG and SGR increased significantly as feeding rate increased from 0 to 2.2% BW per day, but decreased in the satiation group (2.4%). Broken-line regression analysis of WG showed that the optimum feeding rate of growing and sub-adult olive flounder were 1.98% and 0.55% BW per day, respectively, at the high water temperature.
Effects of Bio-floc System on Growth and Environmental Improvement in the Chinese White Shrimp Fenneropenaeus chinensis
Kim, Min-Su ; Min, EunYoung ; Koo, Ja-Keun ; Kang, Ju-Chan ;
Korean Journal of Fisheries and Aquatic Sciences, volume 48, issue 5, 2015, Pages 688~695
DOI : 10.5657/KFAS.2015.0688
The objective of this study was to investigate the effects of bio-floc system that is composed of effective microorganisms (EM) on the microbial composition and water qualities in rearing water and the growth of Chinese white shrimp, Fenneropenaeus chinensis. To investigate the microbial composition according to the bio-floc levels, the study was conducted at 100 and 150% of bio-floc after 5 and 10 days in bio-floc system. The results showed that total bacteria count (TBC) and the counts of Latobacillus sp., Bacillus sp. and Rhodobactor sp., were significantly decreased after 5 days in bio-floc system. To assess the growth of F. chinensis according to the concentrations of bio-floc, the study was conducted at the bio-floc concentrations; 0 (control), 60, 80, 100, 120 and 140% of the prepared bio-floc for 90 days. The growth factors such as daily length and weight gain were considerably increased at the concentrations of bio-floc 100, 120, and 140% after 90 days. As water quality indicators, the values of total-N, NH
-N and PO
-P were analyzed, and they were significantly decreased at 120 and 140% of bio-floc, compared to the control. The results demonstrated that combination of EM showed the synergic effect on removing N and P.
Embryonic Development of Haploid Olive Flounder Paralichthys olivaceus
Jung, Hyo Sun ; Kim, Youn Kyoung ; Kim, Hyun Chul ; Noh, Jae-Koo ; Lee, Jeong-Ho ; Kim, Dong Soo ;
Korean Journal of Fisheries and Aquatic Sciences, volume 48, issue 5, 2015, Pages 696~703
DOI : 10.5657/KFAS.2015.0696
We investigated the characteristics of embryonic and abnormal organ development in haploid olive flounder, Paralichthys olivaceus, by comparing egg development and histological sections in haploid and diploid individuals. After the mid-blastula transition, abnormal development was observed in haploid fish, including delayed epiboly and malformation of the germ ring and embryonic body. In haploid flounder, Kupffer’s vesicles are irregularly shaped and of variable size compared to diploids. The embryonic body of haploids was shorter and broader than that of diploids and the tail length and size were variable. Most haploid embryos failed to hatch and the few larvae that did, did not survive for more than 6 h. The histological analysis of haploid larvae revealed deformed development in diverse organs, including the eye, otic vesicles, notochord, and neural tube. These results may be related to an abnormality in the axial system of haploid larvae. This study confirmed that the abnormalities of haploid olive flounder were similar to the reported characteristics of haploid syndrome. The abnormalities are caused by delayed epiboly and involution and deformity of Kupffer’s vesicle during egg development.
Effects of Temperature and Light Intensity on the Gametophyte Fragment Growth of Ecklonia cava Kjellman (Laminariales, Phaeophyta)
Kang, Jin Woo ; Chung, Ik Kyo ;
Korean Journal of Fisheries and Aquatic Sciences, volume 48, issue 5, 2015, Pages 704~711
DOI : 10.5657/KFAS.2015.0704
We examined the effects of temperature and light intensity on gametophyte growth of Ecklonia cava Kjellman. The growth of female and male gametophytes was investigated before maturation. Gametophytes prepared from Munseom, Jeju, Korea in October 2014 were separated by sex and maintained under the following conditions: 15℃, 20 μmol·m
, and a 12-h/12-h light/dark cycle. The experiments were conducted at five temperatures (10, 15, 20, 25, and 30℃) and three light intensities (5, 20, and 40 μmol·m
). Daily growth rates were estimated by the increase in filamentous frond area. The optimal growth conditions for female gametophytes were 20℃ and 40 μmol·m
; the optimal conditions for male gametophytes were 15℃ and 20 μmol·m
. The relative growth rates (RGR) of female and male gametophytes decreased at 25℃ and 30℃, respectively. At 30℃, RGRs of gametophytes decreased by approximately 1.0% day
. In addition, RGRs of male gametophytes were higher than those of female gametophytes. These results indicate that female gametophytes were more sensitive to temperature and light intensity than male gametophytes. Moreover, these results suggest that E. cava growth rates could decrease as a result of global warming.
Effects of Salinity on Survival, Oxygen Consumption, and Hematological Response of Greenling Hexagrammos otakii
Oh, Sung-Yong ; Myoung, Jung-Goo ; Park, Jin Woo ;
Korean Journal of Fisheries and Aquatic Sciences, volume 48, issue 5, 2015, Pages 712~718
DOI : 10.5657/KFAS.2015.0712
The effects of salinity on survival, oxygen consumption, and hematological response of greenling Hexagrammos otakii, mean body weight 147.1±3.8 g, were investigated under salinity conditions of 33.4 (control), 33.1, 32.8, 32.2, 31.0, 28.7, 23.9, 14.5, and 3.8 psu, to evaluate physiological effects in relation to changes in salinity. The survival and hematological responses of fish were measured at each salinity after 96- and 24-h exposures. The oxygen consumption rate (OCR) of fish was measured in triplicate under conditions of stepwise salinity exposure (33.4→33.1→32.8→32.2→31.0→28.7→23.9→14.5→3.8 psu) with an interval of 24 h at each salinity, using a continuous flow-through respirometer. No fish mortality was observed in the range of 33.4 to 14.5 psu, but the survival rate was reduced to 53.3% at 3.8 psu after 96 h of exposure. The OCRs did not significantly differ in the range between 33.4 to 28.7 psu (P>0.05), but significantly increased at 23.9 and 14.5 psu, and then dramatically decreased at 3.8 psu compared to the control (P<0.05). Hematological variables, such as glucose, glutamic pyruvic transaminase (GPT), hematocrit, and Na
, were affected by reduced salinity. This result may be applicable for habitat and culture management of greenlings.
Monitoring of Emaciation Disease in Cultured Olive Flounder Paralichthys olivaceus in Jeju (2010-2013), Korea
Kim, Seung Min ; Jun, Lyu Jin ; Park, Myoung Ae ; Jung, Sung Hee ; Jeong, Hyun Do ; Jeong, Joon Bum ;
Korean Journal of Fisheries and Aquatic Sciences, volume 48, issue 5, 2015, Pages 719~724
DOI : 10.5657/KFAS.2015.0719
In this study aiming at the cultured olive flounders in Jeju island of Korea, has performed a total of 216 cases of pathogen tests for the olive flounders which seemingly had the symptom of emaciation in 24 farms on the suspicion of its occurrence from June 2010 to December 2013 and intended to get the basic information about the pathogen. According to the survey results of the emaciation infection status of 24 farms in Jeju over the period of this survey, it was confirmed that 18 (75%) of 24 farms in Jeju are positive in the emaciation infection. Among them, as for the rate of infection per year, it was observed that they are 38% in 2010, 48% in 2011, 50% in 2012 and 60% in 2013, and over the period of this survey the infection rate in accordance with the temperature of water has observed a variety of incidence rates from the summer to the winter season. In addition, according to the results of emaciation infection status for each size, the equivalent showed a detection rate, 54% in 11-20 cm, 43.9% in 21-30 cm and 25.4% in over 31 cm. This result accounts for an important portion among the diseases of farmed olive flounders in Jeju, is considered to be one of the diseases which cause troubles in the farms for olive flounders on land and it is thought that it can be utilized as basic data in order to estimate emaciation which may occur in the similar size of the cultured olive flounders in Jeju island.
Edwardsiella ictaluri Infection in Cultured Yellow Catfish Pelteobagrus fulvidraco Fingerlings in Korea
Kim, Jin Do ; Park, Sung Woo ;
Korean Journal of Fisheries and Aquatic Sciences, volume 48, issue 5, 2015, Pages 725~730
DOI : 10.5657/KFAS.2015.0725
We observed yellow catfish Pelteobagrus fulvidraco fingerlings cultured in land ponds in Korea swimming in a corkscrew spiral pattern while hanging head-up and tail-down at the water surface, before eventually dying. Externally, these fish displayed “hole in the head” disease, pale gills, and hemorrhages in the base of the pectoral and caudal fins; internally they had liver hemorrhages and kidney discoloration. The bacterium Edwardsiella ictaluri (YCK-01 and YCL-01) was identified in the kidneys and livers of diseased fish via phenotypic characteristics and PCR analysis using the ictaluri-specific primers IVS (an intervening sequence) and IRS (the inter-ribosomal spacer). Infectivity challenges by intraperitoneal and immersion routes showed that a representative bacterial strain (YCK) exhibited strong virulence to yellow catfish, with an LD
CFU/fish and 2.5×10
CFU/mL, respectively. This is the first report of E. ictaluri infection in yellow catfish from Korea.
Molecular Identification and Development of a PCR Assay for the Detection of a Philometrid Nematode in Rockfish Sebastes schlegeli
Seo, Han-Gill ; Seo, Jung Soo ; Ryu, Min Kyung ; Lee, Eun Hye ; Jung, Sung Hee ; Han, Hyun-Ja ;
Korean Journal of Fisheries and Aquatic Sciences, volume 48, issue 5, 2015, Pages 731~738
DOI : 10.5657/KFAS.2015.0731
Nematode infection in the epithelial tissue of cultured rockfish Sebastes schlegeli was first reported in 2012. Since then, nematode infections have caused serious economic losses in rockfish aquaculture on the west coast of Korea. Taxonomic and life cycle information for this parasite are currently unknown. In this study, 18S rRNA and cytochrome c oxidase subunit I (COI) genes were used for molecular identification and polymerase chain reaction (PCR) to detect the invisible stages of this parasite. Nucleotide sequences of the 18S rRNA of the rockfish nematode showed 98% identity with that of Philometra morii. Therefore, this rockfish nematode was classified to the Philometridae family. However, we could not identify it to genus level using 18S rRNA. Its COI nucleotide sequences shared 85% and 82% identities with those of Bursaphelenchus sinensis and Philometra overstreeti, respectively. In addition, two gene-specific primer sets were designed based on the 18S rRNA gene to detect the intermediate host and nematode larvae. These primers were specific to this rockfish nematode without cross-reacting to other pathogens. The detection limit of the PCR assay using these primers was 1,000 copies of nematoda plasmid DNA. Therefore, the PCR assay described here is suitable for the detection of nematode DNA within rockfish. In addition, this PCR assay could be used to detect nematode larvae and the intermediate host.
Sexual Maturity and Spawning of Ocean Sunfish Mola mola in Korean Waters
Kang, Min Joo ; Baek, Hea Ja ; Lee, Dong Woo ; Choi, Jung Hwa ;
Korean Journal of Fisheries and Aquatic Sciences, volume 48, issue 5, 2015, Pages 739~744
DOI : 10.5657/KFAS.2015.0739
The sexual maturation and spawning time of female ocean sunfish Mola mola in Korean waters were studied by observing the gonads histologically. Specimens were purchased in a fish market in October 2013 and May, June, and October 2014. Nine females (total length 100-250 cm, gonad weight 31-3,470 g) and one male (total length 131 cm, gonad weight 60 g) were studied. Histologically, the ovaries became active in May and spawning began in July and continued until October. In July, mature oocytes and yolk globule stage oocytes were observed; parts of the gonad showed traces of spawning, while others had degenerated and absorbed any oocytes. By October, many oocytes had degenerated and been absorbed. Therefore, the approximate spawning period of ocean sunfish is from July to October based on histological changes in the gonads. The asynchronous oocyte development suggests that the ocean sunfish is a multiple spawner, as reported previously. The catch distribution data suggest that the waters around Jeju Island are a sunfish spawning area.
Growth and Maturation Period of Silvetia siliquosa in the Natural Population in Jindo, South Korea
Hwang, Eun Kyoung ; Yoo, Ho Chang ; Ha, Dong Soo ; Park, Chan Sun ;
Korean Journal of Fisheries and Aquatic Sciences, volume 48, issue 5, 2015, Pages 745~751
DOI : 10.5657/KFAS.2015.0745
The ecological characteristics of Silvetia siliquosa, an endangered brown alga, were investigated from January to December 2013 in Jindo, South Korea. The S. siliquosa population formed widespread patches on natural rock. Receptacles were observed from March to August when seawater temperatures ranged from 8-26℃. A maturation peak was detected in June, when seawater temperatures were 23.4℃. After embryo release, the alga bleached and only the discoidal holdfast remained after August. Developmental initiation of the thallus occurred at temperatures above 8℃, and receptacle formation required approximately 196 degree-days. This is the first study to examine a S. siliquosa population throughout the entire year in a natural habitat.
Feeding Habits of Larval Konosirus punctatus from the Nakdong River Estuary, Korea
Choi, Hee Chan ; Han, In Seong ; Suh, Young Sang ; Huh, Sung Hoi ;
Korean Journal of Fisheries and Aquatic Sciences, volume 48, issue 5, 2015, Pages 752~759
DOI : 10.5657/KFAS.2015.0752
We examined the feeding habits of larval Konosirus punctatus using 165 specimens collected from May to August 2011 in the Nakdong River estuary, Korea. We found that larval K. punctatus [3.9-8.4 mm notochord length (NL)] are carnivorous, consuming mainly rotifers. Their diet also included small numbers of rhizopods, tintinnids, euglenoids, copepods, larval bivalves, dinoflagellates, diatoms, and unidentified materials. To evaluate ontogenetic changes in dietary composition, we split the larvae into three size groups: < 5 mm, 5-6 mm, and > 6 mm NL. The smallest size group frequently preyed on rhizopods. As NL increased, the number of rotifers increased relative to those of rhizopods. Larvae also showed bimodal feeding for feeding incidence, with peaks in the midafternoon and at midnight, while the mean number of prey per individual peaked at 18:00-19:00 h.
First Annulus Formation and Age Determination for Otoliths of Chub Mackerel Scomber japonicus
Kang, Sukyung ; Jung, Kyung-Mi ; Cha, Hyung Kee ;
Korean Journal of Fisheries and Aquatic Sciences, volume 48, issue 5, 2015, Pages 760~767
DOI : 10.5657/KFAS.2015.0760
First annulus formation and age determination of otoliths were examined for chub mackerel Scomber japonicus collected in Korean waters over the one year from January to December in 2009. Translucent zone was regarded as an annual mark. Age interpretation criteria was based on the data of the number of translucent zone, capture date, and edge type of the otolith, assuming the nominal birthday to be 1 January. Monthly changes in mean marginal index indicated that translucent zone was formed once a year, mainly in June. The otolith of 0-ring group was detected comparing the progression by month of the smaller fish length, appearing to be a single first opaque zone. The average distance from the core to the first translucent zone was ~1.77 mm, provided as supplementary information to increase ageing accuracy. The ageing criteria for chub mackerel was made to determine correct year-class with the purpose of effective stock assessment. This method using nominal birthdate and edge type analysis could estimate age of fish closer to the true age than purely counting the number of translucent zone on a whole otolith.
Seasonal Variations in the Macroalgal Flora and Community Structure in Hallyeohaesang National Park on the South Coast of Korea
Oh, Ji Chul ; Ahn, Jung Kwan ; Kim, Cheol Do ; Jeong, Jang Bang ; Choi, Han Gil ;
Korean Journal of Fisheries and Aquatic Sciences, volume 48, issue 5, 2015, Pages 768~775
DOI : 10.5657/KFAS.2015.0768
Seasonal variability in the marine seaweed community structure was examined in the intertidal zones at nine study sites in Hallyeohaesang National Park, on the southern coast of Korea from March to October 2014. A total of 145 seaweeds were indentified, comprising 15 green, 41 brown and 89 red algae. Coarsely branched seaweeds were the dominant functional group, comprising 58.95% in species number, whereas filamentous, sheet, thick leathery, crustose and jointed calcareous forms comprised 2.63-17.72% each. The seaweed biomass averaged 358.00 g dry wt/m
and it was maximal at Somaemuldo (847.64 g dry wt/m
) and minimal at Gamam (56.51 g dry wt/m
). Based on biomass, the dominant and subdominant seaweeds were Ulva australis at Gamam, Sargassum thunbergii at Sangju, Ulva australis and S.fulvellum at Neukdo, S.horneri at Dala-Bijindo-Somaemuldo, S. thunbergii at Dapo, and Corallina pilulifera at Songdo. Community indices were as follows: dominance index (DI), 0.43-0.71; richness index (R), 8.26-16.50; evenness index (J`), 0.36-0.54; and diversity index (H`), 1.57-2.19. In conclusion, we found that both biomass and the community structure of seaweeds in Hallyeohaesang National Park were similar to those in other studies of the Southern Sea along the Korean peninsula, and that Hallyeohaesang National Park is a relatively favorable habitat for seaweeds. Future studies should examine the changes in seaweed composition and biomass as they relate to climate change and environmental pollution.
Changes in the Community Structure of Fish Collected by a Gape Net with Wings in the Coastal Waters of Jindo Island in Response to a Cold Water Appearance in the Southwestern Sea of Korea
Yoo, Joon-Taek ; Seong, Ki Tack ; Kim, Yeong Hye ;
Korean Journal of Fisheries and Aquatic Sciences, volume 48, issue 5, 2015, Pages 776~782
DOI : 10.5657/KFAS.2015.0776
We examined the community structure of fish off the coast of Jindo Island in response to a cold water appearance in the southwestern sea of Korea each August between 2013–2015. Using a gape net with wings, we collected 31 taxa during the study period, wherein the most dominant species was Engraulis japonicus. Collichthys lucidus and Neosalanx andersoni, which are mainly distributed in the western sea of Korea, increased in abundance and were dominant in August 2013, possibly due to the apparent intrusion of cold water (< 19°C) from offshore into the coastal waters of Jindo Island. Meanwhile, Scomberomorus niphonius and Sardinella zunasi, which are known as warmwater migratory species, increased in abundance and were dominant in August 2015, likely influenced by the warmer water (> 20°C) at the coast, which resulted in a noticeable lessening of the cold water in the study area. However, no significant differences were observed in fish community structure in the month of August between 2013–1015. This implies that the small-scale spatial and temporal variations in the cold water had limited effects on the fish community structure, even though the abundances of several dominant species varied in the coastal waters.
Species Composition of Fish Collected by a Gape Net with Wings in the Coastal Waters of Jindo, Korea
Jeong, Jae Mook ; Yoo, Joon-Taek ; Kim, Heeyong ; Lee, Sun-Kil ; Go, Woo-Jin ; Kim, YeongHye ;
Korean Journal of Fisheries and Aquatic Sciences, volume 48, issue 5, 2015, Pages 783~788
DOI : 10.5657/KFAS.2015.0783
Species composition of the fish in the coastal waters of Jindo was determined using monthly sample collection by a gape net with wings in 2014. Of a total of 41 fishes collected, the dominant species were Engraulis japonicus, Thryssa kammalensis, Sardinella zunasi, Leiognathus nuchalis, Amblychaeturichthys hexanema, Neosalanx anderssoni, Acanthogobius flavimanus. The former three species were the migratory species and the other four species were the resident species. These 7 fishes accounted for 99.6% of the total number of individuals collected. Monthly species composition did not show a clear seasonal trend. The peak number of individuals occurred in May, lowest in November. Fish were divided into four groups by the cluster analysis.
Distribution and Contamination Status of Trace Metals in Surface Sediments of Shellfish Farming Areas in Yeoja and Gangjin Bays, Korea
Choi, Minkyu ; Lee, In-Seok ; Kim, Hyung-Chul ; Hwang, Dong-Woon ;
Korean Journal of Fisheries and Aquatic Sciences, volume 48, issue 5, 2015, Pages 789~797
DOI : 10.5657/KFAS.2015.0789
The concentrations of trace metals (As, Cd, Cr, Cu, Fe, Hg, Mn, Pb, and Zn) were determined in 49 surface sediment samples collected in Yeoja and Gangjin Bays on the south coast of Korea, which contain many shellfish farms, in order to assess the contamination level and to understand the spatial distribution of trace metals. The average metal concentrations in the surface sediments of both bays decreased in the order Fe > Mn > Zn > Cr > Pb > Cu > As > Cd > Hg. There were no differences in metal concentrations between shellfish farms and reference sites. The metal concentrations were significantly higher in Gangjin Bay than in Yeoja Bay. Notably, the Cu, Cd, and Hg concentrations were nearly twice as high in Gangjin Bay as in Yeoja Bay. A multivariate analysis showed a strong correlation among Fe, Mn, Zn, Pb, and Cr in the sediments of both bays, implying that the metal concentrations in the sediments in the study area were mainly dependent on natural processes, such as crustal components and diagenesis. Based on the geoaccumulation index and marine sediment quality guidelines (SQGs), the surface sediments in Yeoja and Gangjin Bays are not polluted by trace metals.
Distribution of Demersal Fish Based on a Combined Acoustic and Trawl Survey during Day and Night in Costal of the South Sea, Korea
Lee, Hyungbeen ; Seo, Young Il ; Oh, Taeg Yun ; Choi, Jung Hwa ; Jo, Hyun-Su ; Choi, Kwang Ho ;
Korean Journal of Fisheries and Aquatic Sciences, volume 48, issue 5, 2015, Pages 798~804
DOI : 10.5657/KFAS.2015.0798
The distributions of demersal fish along the coast of the South Sea, Korea, were estimated from a hydroacoustic survey and bottom trawl catches in April of 2015. Acoustic data were collected at 38 kHz, and converted into the nautical area scattering coefficient (NASC, m
) for 0.1 n∙mile along eight transects during day and nighttime. Various demersal fish species were collected and the dominant species comprised no more than half of the catch. The estimated acoustic density of demersal fish compared well with the cumulative catch weight from bottom trawl catches in daytime, but showed a low correlation at nighttime. The NASC of pelagic fish determined for anchovy was correlated with water temperature. The combined hydroacoustic and trawl method can be used to understand the spatial/temporal structure and estimate the density of demersal fish in coastal areas.
Species Composition of Bycatch Fishes Collected by a Gape Net with Wings in the Coastal Waters of Dolsan-do, Yeosu, Korea
Jeong, Jae Mook ; Yoo, Joon-Taek ; Kim, Heeyong ; Lee, Sun-Kil ; Go, Woo-Jin ; Kim, Yeonghye ;
Korean Journal of Fisheries and Aquatic Sciences, volume 48, issue 5, 2015, Pages 805~809
DOI : 10.5657/KFAS.2015.0805
The species composition of bycatch species in the coastal waters of Yeosu were determined by monthly sample collection using a gape net with wings in 2014. Of a total of 32 fishes collected, the dominant species were Ammodytes personatus, Conger myriaster leptocephali, Sebastes inermis, Trichiurus lepturus, Thryssa kammalensis, Leiognathus nuchalis, Syngnathus schlegeli, Thryssa adelae and Hexagrammos otakii. These 9species accounted for 95.2% of the total number of individuals collected. Most of the fish caught were juveniles and small fishes. Based on the results of multidemensional scaling (MDS) analysis, the bycatch fishes were divided into five group.