Review on Global Crab Production and Its Potential to Aquaculture in Africa

OBODOEFUNA SOMADINA MMADUAKONAM 부경대학교 2021 국내석사

More than 5000 species exist but about 4500 species are true crabs while the others are called hermit crabs that use other animal shells for protection. The culture involves acquiring crablets from the hatchery and rearing in grow-out ponds until it gets to table size. This is mostly done in southeast Asia countries because of the inability to meet the demand only from the wild. Fattening of captured wild juvenile crabs is also a good culture method, mostly done because of low hatchery success in crab culture. Overexploitation of natural crab stock without considering the age, size, and status (gravid) has led to declining wild populations. The interest of many hatchery scientists and private fish farmers in crabs and the provision of crablets has been influenced by growing market demands of crab meat all over the world. Crab culture technology lags behind because of species-dependent challenges in the rearing and reliable production of healthy seed stock. In this paper, the status of crab (Eriocheir Sinensis, Callinectes sapidus, Scylla serrata, Portunus trituberculatus and Portunus pelagicus) aquaculture globally is examined together with technological development and problems hindering the industry. The potential for development of the crab aquaculture industry in Africa is discussed

Evaluating the Mangrove Crab Production of Barangay Concepcion, Kabasalan, Zamboanga Sibugay, Philippines : Finding Sustainability in Coastal Community Development

리만도다이안테리스 Yeungnam University, Park Chung Hee School of Poli 2016 국내석사

Mangrove crab is a natural bounty for our country, they are resilient to grow in the mangrove areas and have the huge potential to change the socio-economic status of the coastal communities in the Philippines. .Mangrove crab farming in the Philippines is a growing industry which expects to meet the increasing local and global demand for mud crabs. Barangay Concepcion in Kabasalan, Zamboanga Sibugay practice mangrove crab farming in the coastal communities where marginal fisher folks experienced an increase in income and improvement in their living conditions. This led to the rise of fisher folks who see the potential of mangrove crab farming as a sustainable livelihood and income. Mangrove crabs have an interdependent relationship with the environment, specifically the mangrove forests. The loss of the mangroves, for whatever motive, will automatically be followed by a decrease in the mangrove crab harvest. 맹그로브 게(Mangrove crab)는 필리핀에 존재하는 풍부한 자원일 뿐 아니라 해안가 마을의 사회경제적 상태를 크게 변화시킬 수 있는 잠재력을 가지고 있다. 맹그로브 게 산업은 성장산업이며 Kabasalan, Zamboanga Sibugay 지역에서는 맹그로브 게의 양식을 통해 가난한 어민들이 소득과 생활수준을 증가시킨 경험이 있다. 이는 생활수준과 소득 향상의 지속가능성을 보여준다. 맹그로브 게의 양식은 환경, 특히 맹그로브 늪지와 상호의존 관계에 있다. 맹그로브 늪지의 손상은 게 양식에 부정적 영향을 미친다. 이 연구는 맹그로브 늪지 보호와 게 양식이 서로 지속가능할 수 있는 방안을 제시한다.

Systematic study on the Superfamily Majoidea (Crustacea : Malacostraca : Decapoda) from Korean waters

이상휘 서울대학교 대학원 2020 국내박사

물맞이게상과는 게하목 중에서 가장 다양한 종이 포함된 분류군 중 하나로 전세계에 900종이 넘게 보고되어있다. 많은 종 수만큼 형태적으로도 다양하여 그동안 종을 동정하거나 계통을 분석하는데 혼란이 있었다. 본 연구에서는 1) 형태학적 형질과 분자생물학적 형질을 이용하여 한국산 물맞이게상과의 분류학적 연구결과를 제시하고, 2) 미토콘드리아 전체 유전체를 이용하여 물맞이게상과의 계통유연관계를 추론하였다. 1장에서는 문헌 및 표본 조사를 통하여 한국해역에 물맞이게류 5과 29속 51종이 서식하는 것을 확인하였고 이에 대한 종목록, 분류검색표, 기재 및 분포 지도 등을 제시하였다. 본 연구를 통해 제주도에서 새롭게 채집된 6속 8종의 물맞이게류를 한국미기록 종으로 보고 하였다. 이와 함께 제주도 근해에서 채집된 종은 20속 33종으로 우리나라 다른 해역에 비해 물맞이게류의 종 다양성이 가장 높았으며 이 중 제주도에서만 발견된 종은 20종이었다. 육지에서 멀리 떨어진 해역에서는 지금까지 한국에서 보고되지 않은 미기록종과 드물게 서식이 확인된 종들을 확인할 수 있었다. 형태적 유사성으로 오동정이 잦았던 Pugettia quadridens sensu lato에 대해 형태 및 COX1 분자 형질을 비교 분석하여 재동정을 하였다. 지금까지 한국에서 P. quadridens로 알려져 있었던 ‘뿔물맞이게’가 P. ferox임을 확인하였고 P. quadridens 역시 서식하고 있는 것을 확인하였다. 본 연구에서 P. pellucens에 대한 한국해역의 서식은 확인하지 못하였는데 한국해역에서의 실존 여부에 대한 후속 연구가 필요하다. 2장에서는 물맞이게상과의 계통유연관계를 추론하기 위해 10종의 미토콘드리아 전체 유전체의 염기서열을 분석하여 결정하였다. 이 중 7종은 뿔물맞이게과, 거미다리게과, 한뿔두드럭게과에서 처음으로 미토콘드리아 전체 유전체의 염기서열이 결정된 것이다. 계통유연관계는 물맞이게상과의 6개 과를 모두 포함시킨 14종의 미토콘드리아 전체 유전체 염기서열을 이용하여 Maximum likelihood와 Bayesian inference 방법으로 분석하였다. 분석결과 긴집게발게과가 가장 먼저 분기되었고 거미다리게과와 한뿔두드럭게과가 그 다음으로 분기된 것으로 추론할 수 있었다. 물맞이게과에 속하는 누덕옷게속의 분류학적 위치에 대한 논의는 추가적인 연구가 필요할 것으로 보인다. 뿔물맞이게과는 아과 수준에서 다계통이었으며, Mithracidae는 뿔물맞이게과와 가장 가까웠다. 물맞이게상과에서 미토콘드리아 유전자 배열 순서의 다양성은 게하목에서도 상당히 높은 것으로 나타났다. 지금까지 알려진 게하목에서의 유전자 배열 순서는 18가지 였으나 물맞이게상과 내에서는 8가지가 나타났다. 일반적으로 유전자 배열 순서는 과 수준에서 보존적인 것으로 알려져 있었으나 물맞이게상과에서는 부분적으로 속 수준에서 보존적인 경향이 나타났다. Majoid crabs belong to one of the most diverse brachyuran taxa, with more than 900 species reported globally. As many morphologically as many species were there, there was confusion in identifying species or analyzing phylogeny. The aims of this study were to 1) study the taxonomy of Korean majoid crabs using morphological and molecular characteristics, and 2) infer the phylogenetic relationships of selected majoid crab species using complete mitochondrial genomes. Chapter 1 presents the results of literature surveys and specimen observations of majoid crab diversity in Korean waters. It includes an updated checklist, a key for identification of Korean majoid crabs, species descriptions including photographs of crab specimens, and distribution maps. The diversity survey confirmed the inhabit of 51 species of 29 genera belonging to 5 families, including nine species of six genera newly reported in Korea. The majoid crab diversity of Jejudo Island, where 33 species of 20 genera were collected, was the highest of the areas surveyed and included 20 species that were unique to the waters surrounding this island. A survey conducted in offshore waters (15 km or more from shore) identified majoid crab species that are rare or have not previously been reported in Korea. Morphology and COX1 molecular characteristics were analyzed and corrected for Pugettia quadridens sensu lato, which was frequently misidentified due to morphological similarity with each other. It has been confirmed that '뿔물맞이게', which has been known as P. quadridens in Korea, is P. ferox. Furthermore, P. quadridens sensu stricto also discovered from Korean waters. In this study, it was not confirmed that P. pellucens inhabit the Korean waters, and further study is needed to investigate the existence of this species. Chapter 2 presents the complete mitochondrial genomes of 10 majoid crab species which were determined to infer the phylogenetic relationships of Majoidea. Seven species of which were first reported in the Epialtidae, Inachidae, and Inachoididae. Phylogenetic relationships were analyzed using the maximum likelihood and Bayesian inference methods applied to the complete mitochondrial genome sequences of 14 species, selected to represent all six majoid crab families. According to the analysis, Oregoniidae was the first to branch, followed by Inachidae and Inachoididae. Phylogenetic placement of the genus Micippa of the Majidae requires further study. The Epialtidae was polyphyletic at the subfamily level, and the Mithracidae was located closest to the Epialtidae. The diversity of gene order patterns in majoid crabs was found to be relatively high in comparison with other brachyurans. Brachyurans are known to have eighteen gene order patterns, with eight of these found only in majoid crabs. Generally, gene order patterns were known to be conservative at the family level, but in Majoidea, there was a tendency to be partially conservative at the genus level.

HPLC-MS/MS determination of perfluorinated alkyl substances in crabs : method validation, bioaccumulation, and human health risk assessment

최서경 Graduate School, Korea University 2020 국내석사

Consumption of seafood is a major contributor to perfluorinated alkyl substances (PFASs) exposure. Crabs contain high levels of PFASs, and different PFASs are concentrated in their tissues depending on their habitat. Despite South Korea importing huge quantities of crabs, no investigation has been conducted on the effect of PFASs exposure. This study investigated the risk of exposure to PFASs when ingesting crabs. To determine the risk of exposure, 19 different PFAS species were measured in the edible parts (body, legs, offal, and eggs) of crabs originating from South Korea (n = 17), China (n = 14), India (n = 7), and Pakistan (n = 31), which were distributed in the fish markets of South Korea. The results revealed that, in contrast to short-chain PFASs, long-chain PFASs (PFCAs≥8, PFSAs≥6, and perfluorooactane sulfonamidoacetic acids (FOSAAs)≥8) were detected in crab samples from all four countries of origin, and in all the edible parts except for the legs. Perfluorooctanoic acid (PFOA; 16.9 ng/g in South Korea, 9.42 ng/g in China) and perfluoro-n-tridecanoic acid (PFTrDA; 5.35 ng/g in South Korea, 2.40 ng/g in China) were the predominant perfluoroalkyl carboxylic acids (PFCAs) detected in the crabs originating from South Korea and China, and perfluorooctane sulfonic acid (PFOS; 7.02 ng/g in Pakistan, 5.88 ng/g in India) was the predominant perfluoroalkyl sulfonic acids (PFSAs) detected in crabs originating from Pakistan and India. These results indicate that PFASs that are accumulated in crabs differ depending on the ocean from which they originate. The concentrations of PFOA and PFOS were significantly higher in the eggs and offal than in the legs and body of the crab. The average daily intake of PFOA and PFOS in South Koreans ranges from 0.01% to 0.07% based on the tolerable daily intake of EFSA and MFDS. These results establish the PFASs profiles and risk assessment of crabs that are distributed in South Korea. Perfluorinated alkyl substances (PFASs) 이 주로 검출되는 식품은 수산물 이며 특히 꽃게에서 높은 수준의 PFASs 가 검출되는 것이 여러 연구를 통해 관측되었고 서식지에 따라 노출되는 PFASs의 종류와 함량이 다른 것으로 알려져 있다. 국내 시장에서는 국내 산과 수입산 꽃게의 유통이 활발히 이루어지고 있지만 꽃게의 PFASs 에 대한 노출의 정도와 위험성에 대한 조사는 이뤄지지 않은 실정이다. 이 연구에서는 한국에서 유통되는 한국산 (n=17), 중국산 (n=14), 인도산 (n=7), 파키스탄산 (n=31) 꽃게를 수집하여 식용 가능한 부위에서 19 종의 PFASs 농도를 정량하여 한국인의 꽃게 섭취에 따른 PFASs의 노출과 인체 위험성을 파악하였다. 원산지 각각의 꽃게 샘플에서 PFASs 의 농도를 확인한 결과 식용 부위 중 다리 부위를 제외한 모든 부위 몸 내장 알 에서 장쇄 PFASs (PFCAs ≥ 8, PFSAs ≥ 6, 그리고 perfluorooactane sulfonamidoacetic acids (FOSAAs) ≥ 8) 가 단쇄 PFASs 보다 상대적으로 우세하게 검출된 것을 밝혀내었다 . 또한 원산지 별로 P FASs 농도를 확인한 결과 한국산과 중국산 꽃게에서는 perfluoroalkyl carboxylic acids (PFCAs) 계열 중에서도 특히 Perfluorooctanoic acid (PFOA; 16.9 ng/g 국산 , 9.42 ng/g 중국산 와 perfluoro-n-tridecanoic acid (PFTrDA; 5.35 ng/g 국산 , 2.40 ng/g 중국산 가 우세하게 검출되었으며 파키스탄과 인도산 꽃게에서는 perfluoroalky l sulfonic acids (PFSAs) 계열 중에서도 특히 perfluorooctane sulfonic acid (PFOS; 7.02 ng/g 파키스탄산 , 5.88 ng/g 인도산)가 우세하게 검출 된 것을 밝혀냄으로 써 해역과 서식지에 따라 PFASs 종의 생체 축적이 다르다는 사실을 알 수 있었다. 한편, PFOA 와 PFOS 가 축적되는 농도가 꽃게의 식용 부위에 따라 차이가 있으며 이러한 원인으로는 과불화화합물이 지방함량이 높은 장기에 축적되는 특성 과 관련이 있고 , 그 증거로 몸 부위 보다 알과 내장 부위 에서 유의적으로 높은 농도가 검출된 것을 관찰할 수 있었다.

Genomic, transcriptomic, and metagenomic analyses of Vibrio species and microbial community composition of crabs harvested at different seasons and locations

김수연 Seoul National University 2016 국내박사

Vibrio vulnificus and Vibrio parahaemolyticus are gram-negative, motile, nonspore-forming opportunistic pathogens that causes foodborne illness associated with the consumption of contaminated seafood. Although many cases of foodborne outbreaks caused by V. vulnificus and V. parahaemolyticus have been reported, the genomes of only few of them have been completely sequenced and analyzed using bioinformatics. In order to characterize overall virulence factors and pathogenesis of V. vulinificus and V. parahaemolyticus associated with foodborne outbreak in South Korea, new strains V. vulnificus FORC_016 and V. parahaemolyticus FORC_008 were isolated from blood of food-poisoning patient or flounder fish and their genome was completely sequenced. The genomic analysis of FORC_016 revealed that the genome consists of two circular DNA chromosomes, and contains 4,461 predicted open reading frames (ORFs), 129 tRNAs, and 34 rRNA genes. V. parahaemolyticus FORC_008 have two circular DNA chromosomes containing 4,494 predicted ORFs, 129 tRNAs, and 31 rRNA genes. The genomic analysis revealed that the V. vulnificus FORC_016 has major virulence genes such as RTX, cytolysin, and metalloprotases. Furthermore, comparative genome analysis identified unique virulence genes of FORC_016 strain, suggesting that this pathogen have unique pathogenesis mechanism which different from other V. vulnificus. While the strain FORC_008 does not have genes encoding thermo-stable direct hemolysin (TDH) and TDH-related hemolysin (TRH), its genome encodes many other virulence factors including hemolysins, pathogenesis-associated secretion systems, and iron acquisition systems, suggesting that it may be a potential pathogen. Subsequent cytotoxicity test of the strain FORC_008 revealed its high cytotoxicity activity, substantiating this. This report provides an extended understanding on V. vulnificus and V. parahaemolyticus in genomic level and would be helpful for rapid detection, epidemiological investigation, and prevention of foodborne outbreak in South Korea. Because the foodborne illness occurs via consumption of contaminated food, it is important not only understanding of the virulence factors but also the transcriptome alteration of pathogens caused by contacting with foods. To identify differentially expressed genes of pathogen under contact with foods, V. vulnificus FORC_016, an opportunistic marine pathogen, was selected for the transcriptome analysis. Swimming crab, a common niche of V. vulnificus, was selected for the model foods. The transcriptomic profiles of V. vulnificus exposed or unexporsed to crab in 1 or 4h were analyzed using a strand-specific RNA-sequencing. By analyzing RPKM (reads per kilobase of transcript per million reads) fold changes of each gene, I identified that 922 and 648 genes were differentially expressed under exposure to crab for 1h and 4h (P value < 0.05, 2 fold threshold). Regardless of incubation time, the genes related with energy production, cell growth, oligopeptide transport, and glucose metabolism were up-regulated, while genes associated with amino acid biosynthesis, nitrogen metabolism, and other sugar metabolism were down-regulated. These result suggested that V. vulnificus could metabolize the component of crab. Also, the genes encoding thermolabile hemolysin was up-regulated, suggesting this virulence gene might be have crucial role for pathogenesis of V. vulnificus FORC_016 when consumed the V. vulnificus FORC_016 contaminated crab. The swimming crab, Portunus trituberculatus, is the most consumed edible crab in South Korea, and their production and consumption have been increased. Although the foodborne illness caused by consuming of swimming crab have been reported each year, the bacterial community in swimming crab has not been fully understood yet. In order to identify the bacterial members in swimming crab depending on seasons and locations, the microbiota in 65 crabs which were collected from different locations in spring and autumn was analyzed by pyrosequencing. The bacterial communities in autumn crab were more diverse in than those in spring. Psychrobacter, Vagococcus, and Carnobacterium were the most abundant genera in spring, whereas Roseovarius was predominant in autumn, but their proportions were influenced by the pathogenic bacterial proportion. These results indicated that the microbiota in swimming crab significantly influenced by seasonal temperature change. The proportion analysis on Vibrio species indicated that intake of crab could cause the foodborne illness. This study provides the extended understanding on composition of bacterial community in swimming crab and the factors influencing crab microbiome.

한반도에 서식하는 달랑게(Ocypode stimpsoni)와 근연종의 집단유전학 연구

김다인 인하대학교 대학원 2023 국내석사

형용사와 결합하는 어미 ‘-게’에 대한 연구

JIN PING 경희대학교 대학원 2023 국내석사

본 연구는 한국어에서 사용빈도가 높은 어미 ‘-게’ 통사적·의미적 특성을 살펴보고 형용사와 결합하는 어미 ‘-게’의 형태적, 통사적, 의미적 용법과 특징을 밝히는 데 목적이 있다. 우선 어미 ‘-게’에 대한 전반적 고찰을 통해, 어미 ‘-게’ 의미기능, 종속적 기능, 파생 접사적 속성 및 다른 부사형 어미와 대조 비교한다. 그리고 형용사와 결합한 어미의 통사적 제약, 통사적 특징 및 다양한 의미 기능을 함께 살펴본다. 1장은 본 연구의 연구 목적과 선행연구를 고찰하여 본 연구의 범위와 방법을 제시하였다. 2장에서는 기존 연구를 통해, 어말 어미의 분류와 체계를 구분하고, 연결어미로서의 ‘-게’의 의미적 기능, 종속적 기능, 파생 접사적 기능 그리고 어미 ‘-게’의 통사적 문법 특성을 살펴본다. 더불어 다른 부사형 어미와 ‘-게’를 비교하여 분석하였다. 3장에서는 우선 어미 ‘-게’의 분포적 특징, 통사적 제약을 고찰하고, 형용사와 결합하는 어미 ‘-게’ 통사적 특징을 살펴보았다. 어미 ‘-게’는 주어 일치, 인칭 제약은 없고, [정도] 의미에서는 유정성 제약도 없다. 형용사와 결합하는 어미 ‘-게’ 파생성은 강하지만, 통사적 의미에서의 접사로 보기는 어려우며 따라서 통사적 어휘 접사 분류로 귀납하는 것이 더 적절하다. 4장에서는 어미 ‘-게’의 의미적 특징을 [목적], [정도], [상태], [방식], [결과] 및 [기타 의미]로 구분하여 살펴보았다. 형용사와 결합하는 어미‘-게’는 한 문장에서 함께 나타나기도 하는 중의성을 가지는 것도 확인하였다. 더불어 ‘형용사어간+게’의 중의성 의미 특성은 형용사에 의한 것인지 아니면, 후속 수식 동사의 속성에 의한 것인지에 따라 다른 것을 확인하였다. 따라서 ‘형용사어간+게’의 의미는 문장을 구성하는 성분과 문장의 전체 의미가 어떻게 상호작용하는지에 의한 것임을 알게 되었다. 5장은 본 연구의 결론 부분으로 연구의 요약 및 결론을 정리한다. 아울러 연구의 한계점과 향후 연구 내용을 제시한다. The purpose of this study is to examine the syntactic and semantic characteristics of the mother "-ge", which is frequently used in Korean, and to reveal the morphological, syntactic, and semantic uses and characteristics of the mother "-ge", which combines with adjectives. First, through an overall review of the ending '-crab', we compare it against the ending '-crab' semantic function, the dependent function, the derivative adjunctive property, and other adverbial endings. In addition, we examine the syntactic constraints, syntactic features, and various semantic functions of the ending combined with adjectives. Chapter 1 presents the scope and method of this study by considering the purpose of this study and previous studies. Chapter 2 distinguishes the classification and system of mother and mother through existing research, and examines the semantic function, subordinate function, derivative function, and syntactic grammatical characteristics of mother '-ge'. In addition, '-crab' was compared and analyzed with other adverbial mothers. In Chapter 3, first of all, the distributional characteristics and syntactic constraints of the mother '-ge' were examined, and the syntactic characteristics of the mother '-ge' that are combined with adjectives were examined. The ending '-ge' has no subject matching and personality constraints, and in the sense of [degree], there is no oiliness constraint. Although the parent '-crab' derivative that combines with adjectives is strong, it is difficult to see it as an affix in a syntactic sense, and therefore it is more appropriate to derive it as a syntactic lexical affix classification. In Chapter 4, the semantic characteristics of the mother '-ge' were classified into [purpose], [degree], [state], [method], [result], and [other meanings]. It was also confirmed that the ending '-crab' combined with the adjective has a neutrality that sometimes appears together in one sentence. In addition, it was confirmed that the characteristics of the double meaning of 'inter-adjective + crab' were different depending on whether it was due to adjectives or the attributes of subsequent modifiers. Therefore, it was found that the meaning of 'interpretation + crab' is based on how the composition of the sentence interacts with the overall meaning of the sentence. Chapter 5 summarizes and summarizes the research as the conclusion part of this study. In addition, the limitations of the study and future research contents are presented.

Investigating Interactions between Climate, Host Life History and Viral Diversity Across a Transhemishpheric Range of Marine Ecosystems

Zhao, Mingli ProQuest Dissertations & Theses University of Mary 2022 해외박사(DDOD)

Marine infectious diseases and pathogens substantially impact the structure and function of marine communities by causing mortalities and altering host behaviors. The interactions between host and pathogen, determining the epidemiological outcomes are affected by many factors including climate, host life history, and human activities. Studies on marine disease epidemiology and ecology, including both natural and anthropogenic transmission pathways, are necessary for better understanding how these factors potentially influence the host-pathogen interactions. A significant proportion of marine pathogens are viruses; they cause severe infectious diseases and mortalities in many marine organisms, including crustaceans. Virus-related diseases and mortalities have been identified and reported in the Atlantic blue crab, Callinectes sapidus, for more than half a century. With a wide geographic distribution across both hemispheres and a temperature-dependent variable life history, blue crab and its pathogenic viruses constitute a well-suited pathosystem for investigating the potential influences of climate, seasonality, and host life history on viral disease emergence and spread in marine ecosystems.This dissertation applied the “blue crab-virus” pathosystem, to investigate factors that potentially influence the interactions between blue crab and its viral symbionts. The studies mainly focused on three objectives: 1) Investigate the influences of climate, seasonality, and host life history on the prevalence and disease ecology of a virus that is pathogenic to blue crab. 2) Assess the influences of climate, seasonality, and host life history on viral genetic diversity and genetic structures across a wide spatial and temporal range. 3) Characterize genome sequences and biological characteristics of newly identified viruses in blue crabs. The studies encompassed in this dissertation demonstrate, in a single host species, that climate, temperature, and host life history traits drive patterns of virus species diversity and genetic variation across the entire range of the host. One significant revelation was the evidence of long-distance movement of virus pathogen genotypes by human transport of infected blue crabs between states in the United States. The dissertation concludes with a discussion of the potential for next-generation sequencing to discover and study the movement of known and newly discovered viruses in marine hosts.

세스랑게 거주지 탑의 물리적 기능에 관한 연구

조대근 성균관대학교 일반대학원 2012 국내박사

본 논문에서는 세스랑게의 건축물인 탑의 물리적 기능에 관하여 해명하는 것을 목표로 연구를 수행하였다. 이를 위해 현장관찰과 CFD 해석 및 실험을 수행하였다. 현장관찰을 통해 탑 주변의 온도와 바람을 측정하였고 CFD 해석을 통해 탑 내부와 외부에서 발생하는 유동현상을 분석하였다. 또한, 실험을 통해 탑과 땅굴 내부에서 발생하는 공기순환 메커니즘을 밝혀냈다. 마지막으로, 탑의 냉각효과와 공기순환 메커니즘을 통해 그 용도를 확인하였다. 가. 탑의 냉각효과 탑은 한 낮의 태양복사에너지의 차단과 열 흡수 및 방출을 통해 탑 내부통로를 비롯한 땅굴 입구 주변의 온도를 낮춘다. 탑이 있을 때, 탑을 비롯한 입구 주변의 온도는 지표면보다 최대 5℃까지 온도가 낮았다. 탑이 없을 때는 입구 주변의 온도가 지표면 온도와 유사하였다. 나. 탑 내부의 공기순환 바람이 불어옴에 따라 탑 내부의 공기가 밖으로 유출되거나 외부의 공기가 탑 안으로 유입되었다. 바람 유속이 2.5m/s 이상 일 때, 탑의 공기순환 유량이 탑이 없는 경우보다 더 많았다. 2.5m/s 이하의 바람 유속에서는 탑의 공기순환 유량과 탑이 없는 경우의 공기순환 유량이 상대적으로 유사하였다. 탑의 유무에 관계없이, 공기순환 전체 유량의 약 60%가 입구에서 지하 15cm까지의 내부에서 발생하였다. 지하 15~20cm 이하의 깊이에서는 공기순환 유량이 전체 유량에 비해 상당히 희박하였다. 결론적으로, 세스랑게는 탑을 땅굴 상부 근처의 냉각 및 적당한 공기순환에 이용하고 있는 것으로 판단되었다. The manicure crab Cleistostoma dilatatum construct cone-shaped tower at the entrance of their deep burrow on intertidal mudflats during neat tides. This tower is five times bigger than the crab’s body. Functions of the tower have not been known yet. The purpose of this paper is to clarify physical functions of manicure crab’s residence tower. Field investigation, CFD analysis and experiment were carried out to achieve this goal. In the field investigation, temperature distribution around the tower was measured by thermocouple and taken on infrared-camera. The wind speed was also recorded by a needle anemometer. Flow fields of the air outside and inside the tower were simulated by the commercial CFD code based on the finite volume method with the κ-ε turbulence and laminar model. Air circulation inside the tower was confirmed by the flow experiment, which was specially designed to measure a highly sensitive pressure variation. A. Cooling effects of the tower Temperature of the burrow entrance with tower was 5℃ lower than that with no tower, when summer daytime temperatures were the hottest on the mudflats. The tower helped the manicure crab to prevent sunshine, absorb and release heat. B. Ventilation inside the tower Ventilation occurred inside the tower due to the pressure fluctuation induced by turbulent wind. Above the wind speed of 2.5m/s, the volume of ventilation with tower was larger than that with no tower. Below the wind speed of 2.5m/s, the volume of ventilation with tower was similar to that with no tower. Regardless of whether or not there was the tower, 60% of total ventilation volume appeared in the inside from the entrance to the underground of 15cm. From the underground of 15 or 20cm to the bottom(the underground of 50cm) of the burrow, the ventilation volume was relatively rare. Consequently, I concluded that the tower of the manicure crab is a great way to take the heat out and circulate the air of the upper burrow.

홍게(Chionoecetes japonicus)의 가공 공정 중 미생물학적 위해요소 중점관리기준 설정에 관한 연구

고준수 강릉원주대학교 대학원 2019 국내석사

본 연구는 홍게의 가공공정 중 미생물학적 안선정을 확보하고자 viable cell count, coliform group, E. coli, S. aureus, Salmonella spp., L. monocytogenes, V. parahaemolyticus 등의 위해요소를 분석하고, 위해도를 측정하여 중요관리점(Critical Control Point, CCP)을 설정하였다. Viable cell count는 모든 가공 공정에서 법적 기준치(105 CFU/mL)를 초과하지 않았으며, Coliform group은 몸통 선별공정에서 2회, 계량 및 입상공정에서 1회 검출되었다. S. aureus는 다리공정의 경우 냉각공정에서 1회 검출되었고, 다리 선별공정과 계량 및 입상공정에서 각각 2회, 3회 검출되었다. 몸통의 경우 선별공정에서 2회, 계량 및 입상공정에서 2회 검출되었고, 나머지 공정에서는 검출되지 않았다. 기타 Salmonella spp., L. monocytogenes, V. parahaemolyticus는 모든 공정에서 검출되지 않았다. 특히, L. monocytogenes는 다른 미생물에 비하여 가공 공정 중에 발생될 가능성은 낮으나, 만약 검출이 된다면 사망을 포함하여 건강에 중대한 영향을 미치는 위험 군에 속하기 때문에 모든 공정에서 Hazard로 설정하였다. 추가적으로 선별공정과 계량 및 입상공정에서 각각 4회, 5회로 가장 많이 검출된 S. aureus 또한 Hazard로 설정하였다. 중요관리점(CCP)은 제품의 품질을 유지하고 L. monocytogenes와 S. aureus가 발생할 경우 추후 이를 허용수준 이하로 제어할 수 있는 공정이 자숙공정 외에는 없기 때문에 자숙공정이 CCP로 설정되었다. 그러나, 자숙공정 이후에 발생되는 미생물학적 위해요소를 제어하기 위한 방법으로 주기적인 작업자의 위생 교육과 가공 공정 중 반제품의 온도관리와 같은 계획이 필요할 것으로 사료된다. This research was carried to secure microbiological safety in manufacturing process of red snow crab. Hazard analysis was performed against viable cell count, coliform group, Escherichia coli, Staphylococus aureus, Salmonella spp., Listeria monocytogenes and Vibrio parahaemolyticus in process of red snow crab and then critical control point (CCP) was determinated. All tests were carried to triplicate on each process of body and leg. Viable cell counts in all sample were less than 105 CFU/mL as a regulation limit at manufacturing process. Coliform group were detected 2 times at body screening process and 1 time at body weighing process. S. aureus were detected 1, 2 and 3 times at cooling process, screening process and weighing process, respectively. Salmonella spp., L. monocytogenes, V. parahaemolyticus were not detected at any process. Especially, L. monocytogenes were determinated hazard at all process although detection time of them was lower than those of other bacteria, because they are very serious to human's healthy if human intake food contaminated with L. monocytogenes. S. aureus were added to hazard at screening and weighing process because of high detection ratio. The boiling process was determinated to CCP because it is only process can keep a quality of product from change of color (Black spoilage and blue stain). However, It is necessary to plan such as a hygiene education of employee and temperature control of semi-finished products during manufacturing process as a method to control microbiological hazard occurring after boiling process.