• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.18 no.3
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• pp.131-141
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• 2013

Stock identification of Todarodes pacificus collected in the East Sea, Yellow Sea and East China Sea during the period from September to December in 2011 was analyzed by morphometric characters and mitochondrial DNA (mtDNA) cytochrome oxidase subunit I (COI) gene nucleotide variations. Frequency distributions of mantle length was analyzed by morphological method with measuring size of T. pacificus. Then each stock was estimated to confirm their maturation for mean mantle length comparing with mean mature mantle length 20-22 cm. According to morphologic stock identification, it is estimated that the northern part of East Sea is categorized as summer stock and the rest parts, including mid /southern part of the East Sea, northern part of the East China Sea and northern part of the West Sea were autumn stock. For genetic analysis, a total 49 haplotypes were defined by 33 variable nucleotide sites. From the extensive haplotype diversity, limited nucleotide diversity and star-like shape of haplotype network, T. pacificus appears to have undergone rapid population expansion from an ancestral population with a small effective population size. Although pair-wise Fst estimates which represent genetic difference among groups were low, there are relatively remarkable difference of Fst between middle and southern part of the East Sea. Although middle part of the East Sea and southern part of the East Sea were situated at the East Sea, genetically separated groups were appeared.

• Applied Biological Chemistry
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• v.39 no.2
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• pp.134-139
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• 1996

In order to effectively utilize marine animal skin wastes in marine processing manufacture, conger eel skin, file fish skin and arrow squid skin as raw material of edible gelatin were screened. Conger eel skin was the highest in the collagen content, followed by Ole fish skin and arrow squid skin, in the order named. In the fish skins, the soluble and insoluble collagens occupied $67.4%{\sim}72.3%\;and\;27.7{\sim}32.6%$, respectively, and in the arrow squid skin, 30.4ft and 69.6ft, respectively. No difference in the amino acid composition between soluble and insoluble collagens was detected. Collagen from the marine animal skin catched in coasted and offshore water in Korea consisted ${\alpha}$ chain and ${\beta}$ chain, and ${\alpha}$ chain were hetero type. The sum of proline and hydroxyproline contents in conger eel skin collagen was higher than that in the other skin collagens, while was lower than that pork skin collagen. Conger eel skin collagen exhibited a higher denaturation temperature in solution and a higher degree of proline hydroxylation, compared with skin collagen of the respective species. The physical properties such as gel strength, melting point and gelling point of conger eel skin gelatin were superior to those of file fish skin and arrow squid skin gelatins.

• Applied Microscopy
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• v.32 no.3
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• pp.247-255
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• 2002

In this study, we carried out immunostaining and immunogold labeling with antibodies to serotonin and somatostatin to examine the characteristics and functions of the neurons that secrete neurotransmitters in optic lobes of Todarodes pacificus and Octopus minor. As a result of immunostaining with anti-somatostatin, the nerve cells of Todarodes pacificus reacted as similar to the anti-serotonin, but in Octopus minor, only large cells in the outer granule cell layer reacted positively. In the immunogold labeling with anti-serotonin, the nerve cells in the inner grande cell layer and medulla of Todarodes pacificus reacted strongly, 30 gold particles being labeled per $0.5{\mu}m^2$ of the cytoplasm. However, in Octopus minor, only 17 gold particles were labeled, which stated a weak reaction. On the other hand, in the anti-somatostatin case, the nerve cells in the outer and inner granule cell layers and medulla of Todarodes pacificus showed strong reaction, 30 gold particles being labeled per $0.5{\mu}m^2$ of the cytoplasm while the nerve cells in the outer granule cell layer of Octopus minor reacted weakly, about 3 gold particles being labeled per the equivalent area. As a result of immunostaining and immunogold labeling with two types of antibodies to each part of the optic lobes, we found that the reactive nerve cells were distributed differently in the two species. In particular, the degree of reactivity to the immunostaining and immunogold labeling appeared stronger in Todarodes pacificus than in Octopus minor.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.34 no.6
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• pp.624-631
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• 2001

The relationship between the catch of squid, Todarodes pacificus, according to the jigging depth and underwater illumination by fishing lamps was investigated during nighttime operations off-Tusima Islands in November 1994 and off-Oki Islands in November 1995. We used echo sounder to observe the distribution of squid. Echo images on the echo sounder showed the distribution of squid at the water layer of 50 meter depth at the beginning of jigging operation. After the time elapsed, a continuous dense image had moved to the layer of 60-80 meters jigging depth. A larger number of squid were caught by jigging machines set at a lowest depth of 90 meters, when it compared with machines set at a 60 meters. However, Catch increased around 60 meters jigging depth, when fishing lamps output were switched to 24 kW halogen lights:.The underwater illumination, under the each light power of fishing lamps of squid jigging boat was continuously measured with an underwater illuminometer. Values of the underwater illumination, when schools were distributed from 60 to 80 meters, ranged from $3.0\times10^{-2}lx\;to\;3.4\times10^{-3}lx$ in average at $80\~360$ kW fishing lamps output of squid jigging boat.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.35 no.6
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• pp.644-653
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• 2002

Sizes of coastal squid jogging boats, their light source output for fishing lamps and daily catch data were collected, for a purpose of evaluating factors on fishing boats, which affect to the squid catch, from four fishing ports (Hakodate, Sado Island, Noto and Tsushima) in Japan. The catch amount was increased as boat sizes and their light source output of fishing lamps were increased up to 100$\~$200 kW class and 11$\~$15 gross tonnage class. The relationship between catch per unit efforts y (box/machine/day), gross tonnage x_{1}, (GT) and light source output for fishing lamps x_2 (kW) is expressed as following formula; $y=4.091+0.18x_1+0.0019x_2$. Thus, 0.1819 boxes of squid catch can be expected, when light source output for fishing lamps increases for 1 kW $(x_2{\leq}200)$ and boat size 1 GT ($x_1\leq15$). It is considered that the boat size which created a shadow area under the jigging boat, is important factor affecting to catch amount, Because larger shadow area created by bigger boat has a possibility to let more squid stay there.

• Proceedings of the Korean Aquaculture Society Conference
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• 2006.05a
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• pp.123-124
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• 2006

• Proceedings of the Korean Society of Fisheries Technology Conference
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• 2005.05a
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• pp.19-22
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• 2005

• Proceedings of the Korean Society of Fisheries Technology Conference
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• 2010.05a
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• pp.39-40
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• 2010

• Proceedings of the Korean Society of Fisheries Technology Conference
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• 2009.05a
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• pp.127-130
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• 2009

• Proceedings of the Korean Society of Fisheries Technology Conference
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• 2009.05a
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• pp.13-16
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• 2009