• Fisheries and Aquatic Sciences
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• v.22 no.10
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• pp.22.1-22.7
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• 2019

The functional peptides from protein hydrolysates of various fishery sources have been identified such as antioxidant activity. The main intention of this study was purification and characterization of antioxidative peptide from black eelpout muscle. The antioxidative peptides were purified from black eelpout (Lycodes diapterus) muscle using different proteases. Antioxidant activity of black eelpout hydrolysates was evaluated using DPPH radical scavenging activity. Among six hydrolysates, the pepsin hydrolysate had the highest antioxidant activity compared to the other hydrolysates. Therefore, it was further purified and a peptide with seven amino acid residues of DLVKVEA (784 Da) was identified by amino acid sequence analysis. The EC₅₀ value for scavenging DPPH radicals by purified peptide was 688.77 μM. Additionally, the purified peptide exhibited protective effect against DNA damage induces by oxidation in mouse macrophages (RAW 264.7 cells). The results of this study suggest that black eelpout muscle protein hydrolysate could potentially contribute to development of bioactive peptides in basic research.

• Fisheries and Aquatic Sciences
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• v.15 no.2
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• pp.99-105
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• 2012

The biochemical composition of muscle from three deep-sea animals, Tanaka's eelpout Lycodes tanakae magistrate armhook squid Berryteuthis magister, and ocean sunfish Mola mola caught in the East sea in South Korea was determined. The moisture (81.4-93.8 g/100 g), crude protein (5.0-15.6 g/100 g), crude lipid (0.1-1.5 g/100 g), and ash (1.0-1.1 g/100 g) contents of the two fishes were analyzed. The proximate composition of magistrate armhook squid was: moisture 84.0 g/100 g, crude protein 12.4 g/100 g, crude lipid 0.7 g/100 g, and ash 1.5 g/100 g. There was little difference in the proximate compositions of the three animals. The total amino acid contents of Tanaka's eelpout, magistrate armhook squid, and ocean sunfish were 14.64, 10.75, 3.10-9.95 g/100 g, respectively. High levels of glutamic acid, aspartic acid, lysine, leucine, and arginine were found, while low levels of histidine, glycine, and cysteine were detected in the animals. A survey of the free amino acid contents of the animals revealed large amounts of alanine and glycine. Significant differences were found in the fatty acid composition among the three species. Specially, different saturated fatty acids (17.14-40.49%) such as C16:0, and C18:0, monounsaturated fatty acids (19.19-46.88%) such as C16:1, and C18:1, and polyunsaturated fatty acids (35.41-57.08%) such as EPA, and DHA was identified. Our results suggest that each of these deep sea animals possesses nutritional value and should be considered as a foodstuff.

• Journal of fish pathology
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• v.28 no.2
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• pp.79-85
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• 2015

A specimen of porous-head eelpout Bothrocara hollandi (Zoarcidae: Perciformes) caught from the East Sea was found to harbour a myxosporean parasite. Numerous whitish pseudocysts were scattered throughout the body musculature of this individual specimen. Fresh myxosporean spores were found from the squashed pseudocysts under light microscopy. They were subspherical in frontal view with a length of $11.9(11.0{\sim}13.5){\mu}m$, width of $11.6(10.7{\sim}13.6){\mu}m$, and thickness of $7.8(6.9{\sim}8.8){\mu}m$. Two polar capsules were almost equally pyriform with a length of $4.4(3.2{\sim}5.3){\mu}m$ and width of $3.3(2.4{\sim}4.2){\mu}m$. Morphometric and host ecology analysis revealed that this myxosporean parasite could be identified as Myxobolus aeglefini Auerbach 1906. Phylogenetic analysis based on 18S rDNA sequences also revealed that M. aeglefini was clustered with M. albi and M. groenlandicus in the same branch, sharing 97.7% and 96.9% sequence similarities with M. albi and M. groenlandicus, respectively.

• Korean Journal of Ichthyology
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• v.12 no.1
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• pp.54-61
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• 2000

Feeding habits of Zoarces gilli collected in the coastal water off Gadeok-do, Korea from March 1998 to February 1999 were studied. Z. gilli was a carnivore and consumed mainly shrimps, gammarid amphipods, fishes, bivalves and cumaceans. Its diets also included small quantities of copepods, caprellid amphipods, ostracods, crabs, squids, gastropods, ophiuroids and polychaetes. It showed ontogenetic changes in feeding habits. Individuals of small size (10~15 cmSL) fed mainly on small prey organisms such as gammarid amphipods, bivalves, cumaceans and ostracods. However, larger shrimps and fishes were heavily selected with increasing fish size.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.49 no.1
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• pp.1-17
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• 2013

The investigation for species composition and catch in the Korean deep-water of the East Sea (also known as Sea of Japan) was carried out with trammel nets of 7 mesh sizes (6.1~24.2cm) offshore Donghae (2006) and Yangyang (2007) of Korea. The catches were 1,268kg and composed of 37 species between 200m and 1,200m in depth. The principal species caught were Taknka's snailfish, salmon snailfish, red snow crab, hunchback sculpin, snow crab, spinyhead sculpin, Tanaka's eelpout, Alaska cod and so on. Those were target fish for commercial value except salmon snailfish. The mesh sizes for the largest catch were 10.6cm and 15.2cm in the fishing ground of Donghae and Yangyang, respectively. The habitat of snow crab was shallower than that of red snow crab in both areas. Trammel net enabled to investigate fish in deep-water with small fishing vessel and rather cheap expenses in contrast to bottom trawl that required too much of it. With increasing inner mesh size of trammel net the mean size of some principal species such as Taknka's snailfish, spinyhead sculpin, hunchback sculpin, Pacific cod, snow crab, red snow crab and hybrid between snow crab and red snow crab tended to be large in certain range of mesh size.

• Korean Journal of Ichthyology
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• v.18 no.3
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• pp.273-279
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• 2006

A taxonomic study of the family Zoarcidae was conducted using fish collections deposited in the Department of Biology, Chonbuk National University, Jeonju, Korea and the East Sea Fisheries Research Institute, Korea. Among these collections, the following four species of the genus Lycodes are recognized as the first records for Korea; L. sadoensis, L. japonicus, L. pectoralis, and L. sigmatoides. These species are here redescribed and figured, with their distributions and a provisional key to five genera and eleven species of the family Zoarcidae from Korea.

• Journal of the Korean Magnetic Resonance Society
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• v.26 no.4
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• pp.46-50
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• 2022

Antifreeze proteins (AFPs) bind to the ice crystals and then are able to inhibit the freezing of body fluid at subzero temperatures. Type III AFPs are categorized into three subgroups, QAE1, QAE2, and SP isoforms, based on differences in their isoelectric points. We prepared the QAE2 (AFP11) and SP (AFP6) isoforms of the notched-fin eelpout AFP and their mutant constructs and determined their temperature gradients of amide proton chemical shifts (𝚫δ/𝚫T) using NMR. The nfeAFP11 (QAE2) has the distinct 𝚫δ/𝚫T pattern of the first 3₁₀ helix compared to the QAE1 isoforms. The nfeAFP6 (SP) has the deviated 𝚫δ/𝚫T values of many residues, indicating its backbone conformational distortion. The study suggests the distortion in the H-bonding interactions and backbone conformation that is important for TH activities.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.47 no.3
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• pp.255-263
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• 2014

We investigated the reproductive characteristics of Lycodes tanakae in the coastal waters of the middle East Sea to elucidate the species' population structure. We investigated Lycodes tanakae maturation and spawning based on samples collected by Danish seine and gill nets from January 2012 to December 2013. We analyzed monthly changes in maturity stage, gonadosomatic index (GSI), egg diameter, fecundity, and total length at 50% group maturity. The spawning period was December to February, while fecundity ranged from 1,677 eggs at 57.3 cm (total length;TL) to 6,445 eggs at 75.7 cm. The relationship between TL and fecundity (F) was $F_e=6E-05TL^{3.127}$ ($R^2$ = 0.516), and F increased with increasing TL. We estimated the TL at 50% group maturity as 60.4 cm for females and 59.8 cm for males. This study is the first report of Lycodes tanakae reproductive characteristics in the coastal waters of the middle East Sea.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.46 no.6
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• pp.843-850
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• 2013

The feeding habits of Lycodes tanakae Eelpout were studied with 722 specimens collected from March 2011 to December 2012 in the coastal waters of the middle East Sea. The main prey of L. tanakae were fish, molluscs and arthropods. Nevertheless annelida, echinodermata and others were found in small amounts in the stomach contents. The L. tanakae stomach was empty of contents in 50.9% of specimens. While smaller size specimens of L. tanakae (less than 40 cm) fed mainly on euphausiids and amphipods, the larger specimens (more than 40 cm) fed on the fish Allolepis hollandi and Icelus cataphractus, and the molluscs Berryteuthis magister and Watasenia scintillans. The main prey items of L. tanakae varied seasonally. The fish Lycodes nakamurai was the dominat prey from November to January during its spawning season. Euphausiids and amphipods of the arthropods were the dominant prey from February to April. The molluscs Berryteuthis magister and Watasenia scintillans were the dominant prey from May to September. The diversity index (H') of diets showed variations by length class and month; the highest values were 2.61 in the length class of 51-55 cm, and the monthly highest were 2.68 in September with 23 species and 2.65 in November with 18 species. The highest dominance index (D') of diets was 0.57 in the length class of 31-35 cm, and the monthly highest was 0.71 in February. Cluster analysis divided prey groups into four groups by length class and three groups by monthly prey items. The gonad index gradually increased during the process of maturation while, contrary, stomach content index decreased during this period.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.39 no.2
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• pp.87-91
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• 2003

Experimental fishing was carried out to investigate the survival rate of fishes discarded after hauling from the trawl and to develop the fishing gear and method for fisheries management which can improve the survival rate of young fishes escaped from the trawl codend in offshore korean southern sea and off Cheju Island of Korea. The young fishes were bred in fish cage on the board to measure the sustainable survival time for fishes escaped from grid panel and codend. The obtained results are summarized as follows' 1. Japanese flying squid(Todarodes pacjficus), mitra squid(Loligo chinesis), hair-tail( Trichiurus lepturus), john dory(Zeus japonicus), spanish mackerel(Scomberomorus niphonius), redlip croaker (Pseudosciaena polyactis) and blackthroat seaperch(Doederliinia berycoides) were dead instantly after hauling. 2. Survival rate of tiger shark(Galeocerdo cuvier), conger eel (Conger myriaster), red skate (Dasyatis akajei), black scraper(Navodon modestus) and japanese fan lobster(Ibacus ciliatus) might be high after discarding because they survived for long hours in fish cage. 3. Blotched eelpout(Zoarces gili) escaped from the escapement device(grid) was dead within 6 hours in the water tank installed on the board but 97% of tiger shark and 72% of conger eel survived over 72 hours. 4. Red skate escaped from trawl codend was dead within 60 hours in the water tank installed on the board but sustainable survival time of 25% of octopus(Paroctopus dofleini) and 100% of black scraper was over 72 hours. 5. Compared with the survival rate of rosefish(Helicolenus higendorfi) escaped from the escapement device(grid) and trawl codend, all of the rosefish escaped from the grid was dead within 7.2 hours but 8.3% of the rosefish escaped from the codend survived over 72 hours. 6. In comparison with the survival rate of japanese fan lobster survived over 72 hours, survival rate of japanese fan lobster escaped the codend was much higher as 75% than 33% of japanese fan lobster escaped from the grid.