• Parasites, Hosts and Diseases
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• v.45 no.3
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• pp.199-204
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• 2007

Metacercariae of Gynaecotyla squatarolae (Digenea: Microphallidae) were discovered from the shore crab, Macrophthalmus dilatatus, purchased at a market in a coastal town of Taean-Eup, Chungcheongnam-do, Republic of Korea. Their adult flukes were confirmed by experimental infection of rats. The metacercariae of G. squatarolae were elliptical ($391.1{\times}362.5{\mu}m$), and the excysted metacercariae had progenetic genital organs, including the ovary and testes. To obtain adult flukes, 6 Sprague-Dawley rats were fed 500 metacercariae each, and killed at days 2, 4, and 6 post-infection. The adult flukes were identified as G. squatarolae (Yamaguti, 1934) Yamaguti, 1939, based on morphological characters, including 2 ventral suckers (1 large and 1 small), a large genital atrium equipped with the cirrus and the metraterm, separated male and female genital pores, a transversely long cirrus pouch, and extensive vitelline follicles. In the present study, it has been first proven that the shore crab M. dilatatus is a second intermediate host for G. squatarolae in the Republic of Korea.

• Parasites, Hosts and Diseases
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• v.48 no.4
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• pp.335-338
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• 2010

Maritrema spp. (Digenea: Microphallidae) are parasites of birds, but have not been found in the Republic of Korea. In this study, metacercariae of Maritrema sp. were discovered in the Asian shore crab, Hemigrapsus sanguineus, caught in the mud-flats of Jebu-do, Hwasung-gun, Gyeonggi-do, and the adult flukes were confirmed by experimental infection into mice. Based on the symmetric ribbon-like vitellarium, adult flukes of Maritrema sp. were identified, but did not belong to previously described species in terms of the following morphologic characteristics: ceca reaching to the lateral wall at the anterior border of the ovary; ventral sucker larger than oral sucker; a prominent metraterm; and vitellarium forming a complete ring. Hence, we named this microphallid M. jebuensis n. sp. after the island where the second intermediate hosts were collected. From this study, it has been shown that Maritrema sp. is distributed in Korea and transmitted by the Asian shore crab, H. sanguineus.

• Animal cells and systems
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• v.15 no.3
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• pp.243-249
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• 2011

The genetic diversity and population history of the Asian shore crab, Hemigrapsus sanguineus, were investigated with a nucleotide sequence analysis of 536 base pairs (bp) of the mitochondrial cytochrome c oxidase subunit I gene (COI) in 111 samples collected from four populations in Korea and one in Japan. In total, 28 haplotypes were defined by 27 variable nucleotide sites in the COI region examined. The observed haplotypes had a shallow haplotype genealogy and no geographical associations. Most of the populations had high haplotype diversity (0.656-0.788) and low nucleotide diversity (0.00165-0.00244), and significant negative values for Fu's $F_S$, suggesting rapid and recent population growth from an ancestral population and sudden population expansion. The pairwise fixation indices ($F_{ST}$) estimated with the exact test and the migration rates indicate that substantial gene flow occurs among these populations as a result of sea currents, except between the Yellow Sea coast of Korea (BUA) and the Pacific Ocean coast of Japan (JPA). These two populations (BUA and JPA) showed significant genetic differentiation and low migration rate.

• The Korean Journal of Zoology
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• v.34 no.3
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• pp.289-299
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• 1991

Two new species of the genus Hemicyclops, H. 형omsoensis n. sp. and H. soxatilis n. sp., taken from crab burrows on each of mud flat and rocky shore, are described from the Yellow Sea coast of southwest Korea.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.35 no.2
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• pp.122-129
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• 2002

In order to elucidate a responsible mechanism for the development of the odor characteristics of cooked desirable flavoring materials such as crab and shrimp, shore swimming crab flesh were extracted with various solvents and resulting extracts were evaluated organoleptically after cooking. As a result, $80\%$ aqueous methanol extract (AME) was found to produce a cooked desirable flavoring odor. After dialysis of AME, outer dialyzate was fractionated by ionexchange column chromatography, and each of the fraction obtained was subjected to cooking, fellowed by organoleptic evaluation. The outer dialyzate fraction, acidic and amphoteric fraction produced a cooked crab-like odor, On the basis of the composition of $80\%$ AME, an artificial crab extract was prepared with pure chemicals. The artificial crab extract thus obtained closely resembled $80\%$ AME in respect of the cooked odor. To elucidate the role of individual components, the artificial extracts from which certain component alone or as group was omitted were subjected to organoleptic evaluation after cooking. All of neutral, acidic, basic, and sulfur containing amino acids and quarternary base compounds were involved in the development of the cooked crab-like odor. The cooked odor of artificial extract without addition of ribose was lacking in the characteristics of cooked crab odor, and phosphorus compound accelerated the development of the cooked crab-like odor.

• Biomaterials and Biomechanics in Bioengineering
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• v.2 no.4
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• pp.249-269
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• 2015

A problem faced by oil companies is the maintenance of the location register of pipelines that cross the surf zone, the regular survey of their location, and also their inspection. A survey of the state of art did not allow identifying operating systems capable of executing such tasks. Commercial technologies available on the market also do not address this problem and/or do not satisfy the presented requirements. A possible solution is to use robotic systems which have the ability to walk on the shore and in the surf zone, subject to existing currents and ripples, and being able to withstand these ambient conditions. In this sense, the authors propose the development of a spider crab biologically inspired robot to achieve those tasks. Based on these ideas, this work presents a biomechanical study of the spider crab, its modeling and simulation using the SimMechanics toolbox of Matlab/Simulink, which is the first phase of this more vast project. Results show a robot model that is moving in an "animal like" manner, the locomotion, the algorithm presented in this paper allows the crab to walk sideways, in the desired direction.

• Fisheries and Aquatic Sciences
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• v.15 no.1
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• pp.49-56
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• 2012

Genetic variation in the Asian shore crab Hemigrapsus sanguineus was determined from partial mitochondrial DNA (mtDNA) sequences of the cytochrome b (Cytb) gene. Samples included 143 crabs from six localities along three coastlines in South Korea. A nucleotide sequence analysis revealed 38 variable sites in a 470-bp sequence, which defined 37 haplotypes. The haplotypes were not associated geographically and had a shallow genealogy. Pairwise $F_{ST}$ tests and a two-dimensional scaling analysis revealed no significant genetic differentiation among most of the populations. The low pairwise comparison values, but significant genetic differentiation of a northeastern population from all other populations, might have been influenced by a restriction in gene flow caused by hydrographic conditions such as ocean boundaries. The high haplotype diversity, low nucleotide diversity, and time since H. sanguineus expansion in Korean coastal waters indicate rapid population growth and a recent, sudden expansion in the Late Pleistocene.

• Journal of the Korean Society of Food Science and Nutrition
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• v.30 no.5
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• pp.787-795
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• 2001

For the developing natural fisheries flavoring substances using crustacea, the flavor constituents of enzyme hydrolysates from shore swimming crab (crab) and spotted shrimp (shrimp) were investigated. In taste-active compounds of both enzyme hydrolysates, total free amino acid contents of crab and shrimp enzyme hydrolysates were 5,226.7 mg% and 8,757.3 mg%, respectively. The major amino acids were taurine, glutamic acid, proline, asparagine, glycine, alanine, valine, leucine, lysine anserine and arginine. As for ATP related compounds, AMP was the principal component and small amounts of IMP was detected in both enzyme hydrolysates. In the quarternary ammonium bases, betaine was the principal component (593.8mg%), and contents of TMAO and betaine in both samples were 60.7 mg% and 850.0 mg%, 124.1 mg% and 755.9 mg%, respectively. The major components were Na, K, P and Cl in inorganic ions. The major fatty acids of both sample were 14 : 0, 16 : 0, 16 : 1n7, 18 : 1n9, 20 : 5n3 and 22 : 6n3, and composition ration of n3 polyunsaturated fatty acids of were 27.8% and 28.5%, respectively. Total 99~109 volatile compounds were detected as a cooked odor of crab and shrimp enzyme hydrolysates by SDE apparatus/gas chromatography/mass spectrometry. The volatile flavor compounds identified from cooked crab enzyme hydrolysate were composed of 6 acids, 10 alcohols, 7 aldehydes, 11 ketones, 1 ester, 5 phenols, 4 benzenes, 22 hydrocarbons, 1 furan, 21 nitrogen containing compounds and 11 micellaneous compounds. And the volatile flavor compounds indentified from cooked shrimp enzyme hydrolysate were composed of 13 acids, 10 alcohols, 6 aldehydes, 10 ketones, 3 esters, 2 phenols, 5 benzenes, 36 hydrocarbons, 1 furan, 14 nitrogen containing compounds and 8 micellaneous compounds.

• Fisheries and Aquatic Sciences
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• v.10 no.2
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• pp.86-92
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• 2007

Adult Dungeness crabs are restricted primarily in the lower part of Glacier Bay, Alaska, but the interaction of larval dispersion and adult distribution is unknown. To understand the larval occurrence in the upper part of Glacier Bay, Dungeness crab larvae, sea surface temperature (SST), and sea surface salinity (SSS) were collected at 16 near-shore and 12 mid-channel stations in Glacier Bay, southeastern Alaska during six sampling periods from March through August 2000. Each station was visited from one to five times during the entire sampling period. Geographic Information System (GIS) was used to contour SST and SSS distribution in Glacier Bay. Seven to 27 stations were visited during each sampling period. Most larvae (85% were zoeae I) occurred during May 31 to June 14, 2000. Larval density varied from none to $51.4\;100\;m^{-3}$ between stations. A few later stage larvae occurred during later sampling periods. Overall, no relationship between larval densities, and SSS, and SST existed. Larvae occurring in the upper bay were probably transported by tidal currents from the lower bay; adult Dungeness crabs in Glacier Bay have a relatively high density near the mouth of the bay but decrease sharply around 40km north of the mouth. The lack of adult crabs in the upper 60km of the bay may be related to lower salinity, resulting in sharp haloclines, or colder temperatures which are not conducive to survival or growth of either larvae or adults.

• The Journal of Fisheries Business Administration
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• v.52 no.2
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• pp.1-31
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• 2021

This study is to evaluate the prior economic feasibility of the off-shore fisheries stock enhancement project. The main findings of this study can be summarized as follows: first, offshore fisheries stock enhancement project shall be implemented by dividing them into 1st·2nd·3rd projects for efficient promotion. The 1st·2nd·3rd projects will be conducted in a total of 50 locations (the eastern sea, the western sea, the southern sea, and the jeju sea areas), and the project period per unit will be five years, which will cost 1 trillion won. Second, according to the results of the survey on public awareness, the most consumed marine species in Korea over the past year were analyzed in the order of mackerel, hairtail, squid, yellow corvina, blue crab, and cod. The dominant response to the reason for consuming marine products in Korea was healthy well-being food and safe food. In addition, 67.9% of them have hesitated to purchase offshore fish species over the past year due to high prices, indicating that they are burdened by high prices. On the other hand, 79% of the respondents said that the government's policy was insufficient, according to a survey on whether the government's coastal marine resource creation policy was sufficient. Third, as a result of preliminary economic analysis of offshore fisheries stock enhancement project, the benefit-cost ratio is 4.01, net present price is 1,283.7 billion won, and internal rate of return is 91.7% per year, which means that the economic analysis ensures the feasibility of the projects. The results of this study provide useful information on securing or organizing budgets for offshore fisheries stock enhancement project by securing economic feasibility as a national infrastructure project that increases fishery income and public benefits such as consumption of marine products.