National Institute of Fisheries Science
National Institute of Fisheries Science
Myun Park J.,Macquarie University |
Nam Kwak S.,Environmental Ecological Engineering Institute Co. |
Huh S.-H.,Pukyong National University |
Han I.-S.,National Institute of Fisheries Science
Deep-Sea Research Part II: Topical Studies in Oceanography | Year: 2017
Dietary niches and food resource partitioning can support the coexistence of many fishes in benthic marine systems, which can lead to the greater abundances of those species that can potentially support their fisheries. Diets and niche overlap among nine demersal fish species were investigated in the southern continental shelf of East/Japan Sea, Korea. Specimens were collected monthly from January to November 2007 on soft bottoms between 40 and 100. m depth using a bottom trawl. A total of 20 prey taxa were found in 1904 stomachs of the nine species. Comparison of the stomach contents among the nine species showed that inter-specific dietary compositions differed significantly. Although all fish species consumed similar types of prey items, their contributions to the diet of different species varied. Among prey taxa, carid shrimps contributed greatly to the diets of Amblychaeturichthys hexanema, Amblychaeturichthys sciistius, Coelorinchus multispinulosus, Lepidotrigla guentheri, and Liparis tanakae, whereas polychaetes and teleosts contributed to the diets of Callionymus lunatus and Lophius litulon, respectively. On the other hand, carid shrimps and teleosts together contributed to the diets of Pseudorhombus pentophthalmus. Non-metric multivariate analysis of the mass contributions of dietary categories for food resources emphasized visually that the dietary compositions of the nine species differed. Although C. multispinulosus, L. guentheri, L. litulon, and L. tanakae showed similar dietary compositions between small and large size classes, ontogenetic diet changes of the remaining six species were evident. Feeding relationships among the nine demersal species were complicated, but inter- and intra-specific differences in dietary composition among the species reduced potential competition for food resources within the fish community in the southern continental shelf of East/Japan Sea, Korea. © 2017 Elsevier Ltd.
Kim Y.D.,National Institute of Fisheries Science |
Choi J.-S.,Silla University
Journal of Animal and Plant Sciences | Year: 2017
A total of 38 methanol and water extracts of macroalgal species (18 brown, 14 red, and 6 green) collected from the Korean coast were investigated for their lethality to brine shrimp larvae. Of the solutions tested, methanol extracts of six species (15.79%) showed larvicidal effects against Artemia salina. Aqueous extracts of two species (5.26%) were lethal to A. salina. The brown algae Dictyota dichotoma, Ecklonia kurome, Ishige okamurae, Sargassum sagamianum, and Pachydictyon coriaceum, and the green algae Enteromorpha linza and Ulva pertusa, displayed significant larvicidal activity in 2.5% methanol extracts. None of the methanol extracts of the 14 red algae species tested had larvicidal effects. The brown alga Colpomenia bullosa and the red alga Lomentaria catenata displayed significant larvicidal activity in 2.5% extracts. No larvicidal effects were observed from extracts of green algae. These results offer insight into the larvicidal potential of Korean seaweed extracts. © 2017, Pakistan Agricultural Scientists Forum. All rights reserved.
Lee Y.-J.,Gwangju Institute of Science and Technology |
Kang H.Y.,Gwangju Institute of Science and Technology |
Lee W.C.,National Institute of Fisheries Science |
Kang C.-K.,Gwangju Institute of Science and Technology
Estuaries and Coasts | Year: 2017
The pattern of somatic growth of the Pacific oyster Crassostrea gigas cultured in suspension in Geoje–Hansan Bay, Korea was evaluated between July 2013 and March 2014 comparing culturing sites and depths. Gross biochemical composition of oyster tissues provided a measure of physiological status, and clearance rates of oysters provided a measure of feeding physiology at different water flow speeds. A growth curve model indicated greater tissue growth in the surface than in the bottom layers, and advanced summer growth by more than 4 months in the stagnant inner bay compared with winter growth in the more rapidly flowing outer bay. Our results suggest that rapid tissue growth of oysters in the surface layer in summer is supported by high primary productivity in the inner bay. In contrast, oyster growth performance at the outer bay in late fall and winter may be related to seasonal food availability that is regulated by short residence time and thereby rapid renewal of water compared to the inner bay. Furthermore, a combination of the water flow regime of the bay and the flow rate-dependent feeding physiology of oysters proved to be an important determinant of seasonal growth dynamics. Finally, oyster growth was better explained by water flow rates than by hydrographic conditions. © 2017 Coastal and Estuarine Research Federation
Lee J.,National Institute of Fisheries Science |
Kim K.-H.,Pukyong National University
Korean Journal of Microbiology | Year: 2015
All known genomes (N=10) in the order Nitrosomonadales were analyzed to contain 9,808 and 908 gene clusters in their pan- genome and core genome, respectively. Analyses with reference genomes belonging to other orders in Betaproteobacteria revealed that sizes of pan-genome and core genome were dependent on the number of genomes compared and the differences of genomes within a group. The sizes of pan-genomes of the genera Nitrosomonas and Nitrosospira were 7,180 and 4,586 and core genomes, 1,092 and 1,600, respectively, which implied that similarity of genomes in Nitrosospira were higher than Nitrosomonas. The genomes of Nitrosomonas contributed mostly to the size of the pan-genome and core genomes of Nitrosomonadales. COG analysis of gene clusters showed that the J (translation, ribosomal structure and biogenesis) category occupied the biggest proportions (9.7-21.0%) among COG categories in core genomes and its proportion increased in the group which genetic distances among members were high. The unclassified category (-) occupied very high proportions (34-51%) in pan-genomes. Ninety seven gene clusters existed only in Nitrosomonadales and not in reference genomes. The gene clusters contained ammonia monooxygenase (amoA and amoB) and -related genes (amoE and amoD) which were typical genes characterizing the order Nitrosomonadales while they contained significant amount (16-45%) of unclassified genes. Thus, these exclusively-conserved gene clusters might play an important role to reveal genetic specificity of the order Nitrosomonadales. © 2015, The Microbiological Society of Korea.
Park J.C.,Sungkyunkwan University |
Han J.,Sungkyunkwan University |
Lee M.-C.,Sungkyunkwan University |
Seo J.S.,National Institute of Fisheries Science |
Lee J.-S.,Sungkyunkwan University
Aquatic Toxicology | Year: 2017
Triclosan (TCS) is an antimicrobial agent that has been widely dispersed and detected in the marine environment. However, the effects of TCS in marine invertebrates are poorly understood. In this study, the effects of TCS on life cycle history (e.g. mortality and fecundity) along with cellular reactive oxygen species (ROS) levels, GSH content, antioxidant enzymatic activities, and mRNA expression levels of oxidative stress-mediated genes were measured in the copepod Tigriopus japonicus. The no observed effect concentration (NOEC) and median lethal concentration (LC50) of TCS in the adult stage were determined to be 300 μg/L and 437.476 μg/L, respectively, while in the nauplius stages the corresponding values were 20 μg/L, and 51.76 μg/L, respectively. Fecundity was significantly reduced (P < 0.05) in response to TCS at 100 μg/L. Concentration- and time-dependent analysis of ROS, GSH content (%), and antioxidant enzymatic activities (e.g. GST, GPx, and SOD) were significantly increased (P < 0.05) in response to TCS exposure. Additionally, mRNA expression of detoxification (e.g., CYPs) and antioxidant (e.g., glutathione S-transferase-sigma isoforms, Cu/Zn superoxide dismutase, catalase) genes was modulated in response to TCS exposure at different concentrations over a 24 h period. Our results revealed that TCS can induce reduced fecundity and oxidative stress with transcriptional regulation of oxidative stress-mediated genes with activation of the antioxidant system in the copepod T. japonicus. © 2017 Elsevier B.V.
Hwang E.K.,National Institute of Fisheries Science |
Ha D.S.,National Institute of Fisheries Science |
Park C.S.,Mokpo National University
Journal of Applied Phycology | Year: 2017
Cultivations of the brown seaweed, Saccharina japonica, was developed, promoted, and industrialized in the 1970s and is highly valued in Korea both for human consumption and as a feed for the rapidly developing abalone farming industry. Production has continually increased, and approximately 442,637 tonnes wet weight was harvested in Korea in 2015. Abalone is a highly sought-after delicacy in Korea, and the abalone farming industry has been developed based on a stable production of seaweed. Korean abalone farmers prefer to feed their stock on locally cultured S. japonica; however, between August and November, the supply of farmed S. japonica declines because higher seawater temperatures reduce S. japonica productivity. In an attempt to overcome this temperature-induced period of low production, cultivation trials with a strain of S. japonica selected to withstand higher cultivation temperatures were undertaken. Strain selection involved using individual parent thalli that were found to remain productive under high seawater temperature (26 °C) at Wando. Male and female gametophytes were isolated through 3 cycles of free-living gametophyte culture to produce the F3 strain used in the production trials. Production trials using the selected strain were initiated every month between December 2014 and March 2015. This delayed the initiation of culture beyond the latest initiation time currently used by farmers (December). Delaying initiation of cultivation resulted in delayed maximum growth compared to the control. Growth of the F3 strain continued for up to 3 months longer than normally achieved on farms for non-selected thalli. The mean length, growth rate, and biomass were also greater than those achieved by the control strain. The use of the F3 strain of S. japonica coupled with delayed initiation of culture can therefore be used to help to ensure a stable year round algal feed supply for abalone industry in Korea. © 2017 Springer Science+Business Media Dordrecht
Kim Y.D.,National Institute of Fisheries Science |
Kim S.-K.,Silla University |
Choi J.-S.,Silla University
Toxicology and Environmental Health Sciences | Year: 2017
To improve the utility of the inedible ovary of puffer fish, heat and alkaline conditions (pH 9.0) were applied to eliminate its toxicity. The alkaline- and heat- treated ovary extract showed no lethal potential in any group tested using a mouse bioassay and a brine shrimp lethality assay. In addition, the considerable anti-erythematic and anti-edematic effects of detoxified puffer fish ovary extract were evaluated. Based on the results, detoxified puffer fish ovary extract is a promising source of novel anti-inflammatory agents that may be useful when included in dermal care products and for the development of novel therapies for dermal diseases. © 2017, Korean Society of Environmental Risk Assessment and Health Science and Springer Science+Business Media B.V.
PubMed | University of Jaffna, Insilicogen Inc., Marine Life Research, Nihon University and National Institute of Fisheries Science
Type: | Journal: Developmental and comparative immunology | Year: 2017
A -galactoside binding lectin, designated as galectin-2, was identified and characterized from rock bream Oplegnathus fasciatus (OfGal-2). The cDNA of OfGal-2 comprised of 692 bp with a coding sequence of 396 bp, encoding a putative polypeptide of 131 amino acids. Gene structure analysis of OfGal-2 revealed a four exon-three intron organization. A single carbohydrate-binding domain containing all seven important residues for carbohydrate binding was located in the third exon, which formed a carbohydrate-binding pocket. Homology screening and sequence analysis demonstrated that OfGal-2 is an evolutionarily conserved proto-type galectin. OfGal-2 transcripts were detected in several healthy fish tissues, with the highest level observed in the intestine, followed by the liver. The expression of OfGal-2 was elevated upon the injection of various mitogenic stimulants and pathogens in a time-dependent manner. Upregulated expression in the liver after tissue injury suggested its role as a damage-associated molecular pattern. Recombinant OfGal-2 protein had hemagglutinating potential and possessed affinity towards lactose and galactose. Moreover, the recombinant protein agglutinated and bound potential pathogenic bacteria and a ciliate. The results of this study indicate that the galectin-2 from rock bream has a potential role in immunity, particularly in the recognition of invading pathogens.
Hwang D.-W.,National Institute of Fisheries Science |
Lee I.-S.,National Institute of Fisheries Science |
Choi M.,National Institute of Fisheries Science |
Kim T.-H.,Jeju National University
Marine Pollution Bulletin | Year: 2016
In order to evaluate the main source of nutrients for maintaining the high production in shellfish farming bay, we have measured 222Rn activities and the concentrations of nutrients in stream water, seawater, and coastal groundwater around Geoje Bay, one of the largest cultivation areas of oyster in the southern sea of Korea in April 2013. Using the 222Rn and Si mass balance model, the residence time of bay seawater was about 5 days and the submarine groundwater discharge (SGD) into the bay was estimated to be approximately 1.8 × 106 m3 d− 1. The SGD-derived nutrient fluxes contributed approximately 54% for DIN, 5% for DIP, and 50% for DSi of total nutrient input entering into the bay. Thus, our results suggest that SGD is the major source of nutrients in Geoje Bay, and SGD-derived nutrients are very important to support the biological production of this shellfish farming bay. © 2016 Elsevier Ltd
Lee J.,National Institute of Fisheries Science
Fisheries and Aquatic Science | Year: 2015
Postprandial ammonia excretion and oxygen consumption in olive flounder Paralichthys olivaceus fed two different feed types, moist pellet (MP) and expanded pellet (EP) diets, to satiation were determined at 12°C, 15°C, 20°C, and 25°C for 48 h. The ammonia excretion and oxygen consumption rates increased with increasing water temperature. However, the postprandial times for the maximum rates of ammonia excretion and oxygen consumption were shortened from 12 h to 6 h after feeding with increasing water temperature. The ammonia excretion and oxygen consumption rates of fish fed EP were significantly higher (P < 0.05) than those fed MP at 12 h post-feeding both for 12°C and 15°C. The highest (P < 0.05) weight-specific ammonia excretion rates at 12°C were observed in fish fed EP and MP at 12.1 mg NH3-N kg-1h-1 and 8.7 mg NH3-N kg-1h-1, respectively, for 12 h and 9 h after feeding. The highest (P < 0.05) weight-specific oxygen consumption rates at 12°C were observed in fish fed EP and MP at 116.4 mg kg-1h-1 and 101.0 mg kg-1h-1, respectively, for 12 h after feeding. The highest ammonia excretion rates at 25°C in fish fed EP and MP increased to 16.9 mg NH3-N kg-1h-1 and 18.3 mg NH3-N kg-1h-1, respectively, for 6 h after feeding. The highest (P < 0.05) weight-specific oxygen consumption rates at 25°C were observed in fish fed EP and MP at 184.3 mg O2 kg-1h-1 and 197.3 mg O2 kg-1h-1, respectively. These data are extremely valuable for the design of biofilters and development of effluent treatment technologies for land-based flounder farms. © 2015 The Korean Society of Fisheries and Aquatic Science.