• 한국발생생물학회지:발생과생식
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• 제25권1호
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• pp.59-65
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• 2021

The author established a PCR-based genetic platform to examine the hierarchical polar dendrogram of Euclidean genetic distances of one tailfin anchovy population, especially for Coilia nasus, which was further associated with other fish population, by connecting with specifically designed oligonucleotide primer sets. Five oligonucleotide primers were used to generate a total of 260 and 211 scorable fragments in Coilia populations I and II, respectively. The DNA fragments ranged from greater than (approximately) 100 to more than 2,000 bp. The average bandsharing values (BS) of individuals from the anchovy population I (0.693) displayed higher values than individuals from population II (0.675). The genetic distance between individuals established the existence of a close relationship in group II. Comparatively, individuals of one anchovy population were fairly related to other fish populations, as shown in the polar hierarchical dendrogram of Euclidean genetic distances. The noteworthy genetic distance determined between two Coilia nasus populations demonstrates that this PCR technique can be applied as one of the several devices for individuals and/or population biological DNA researches undertaken for safeguarding species and for production of anchovies in the littoral area of Korea.

• 한국어병학회지
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• 제33권1호
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• pp.23-34
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• 2020

In recent years, global warming is causing dramatic environmental changes and deterioration, such as hypoxia, leading to reduced survival rate and growth performance of farmed aquatic animals. Hence, understanding systemic immuno-physiological changes in fish under environmental stress might be important to maximize aquaculture production. In this study, we investigated physiological changes in rainbow trout exposed to hypoxic stress by monitoring changes in blood chemistry, leukocyte population, and expression levels of related cytokine genes. Hematological and serological factors were evaluated in blood obtained from rainbow trout sampled at a dissolved level of 4.6 mg O₂ L^-1 and 2.1 mg O₂ L^-1. Blood and head kidney tissue obtained at each sampling time point were used to determine erythrocyte size, leukocyte population, and cytokine gene expression. The level of LDH and GPT in fish under progressive hypoxia were significantly increased in plasma. Likewise, the (Granulocyte + Macrophage)/lymphocyte ratio (%) of fish exposed to hypoxia was significantly lower than that in fish in the control group. Such changes might be due to the rapid movement of lymphocytes in fish exposed to acute hypoxia. In this study, significant up-regulation in expression levels of IL-1β and IL-6 gene appeared to be involved in the redistribution of leukocytes in rainbow trout. This is the first study to demonstrate the involvement of cytokines in leukocyte trafficking in fish exposed to hypoxia. It will help us understand systemic physiological changes and mechanisms involved in teleost under hypoxic stress.

• 한국환경성돌연변이발암원학회지
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• 제18권2호
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• pp.109-115
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• 1998

Fluorscence in situ hybridization with chromosome-specific probe has been shown to be a valid and rapid method for detection of chromosome rearrangements induced by chemical and physical agents. This method is useful for quantifying structural aberrations, expecially for stable ones, such as translocation and insertion, which are difficult to detect with conventional method in human lymphocyte. In order to use the FISH method as a biodosimeter for monitoring human population exposed to various chemical and physical agent, baseline level of chromosome rearragement was established. Blood from forty four healthy adults were collected and analysed with whole chromosome-specific probes by human chromosome 1,2 and 4. The frequencies of stable translocation were 2.45 per 100 cell equivalent and those of insertion, color juction, acentric and dicentric were 0.32, 3.28, 0.23 and 0.27 per 100 cell equivalent respectively. The frequencies of chromosome rearragements increased with age in both sexes except for dicenrics. From above result, stable aberrations accumulate with age and it may reflect integrated lifetime exposure of adverse environment.

• 한국어병학회지
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• 제19권2호
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• pp.141-153
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• 2006

Genomic DNA samples isolated from two geographical crayfish (Cambaroides similis) populations in the inland of the Korean Peninsula, at Jeonju (Jeonju crayfish; JJC) and Jeongup (Jeongup crayfish; JUe), were PCR-amplified repeatedly. The six arbitrarily selected primers OPC-03, OPC-06, OPC-09, URP-02, URP07 and URP-09 generated the common, specific, and polymorphic fragments. The sizes of DNA fragments also varied widely, from 100 bp - 2,600 bp. Here, 521 fragments were identified in the JJC population, and 354 in the JUC population: 6 primers generated 60 specific fragments (60/521 fragment, 11.5%) in the JJC population, and 90 (90/354 fragments, 25.4%) in the JUC population. These primers produced 42 polymorphic fragments (8.1%) in the DC population, and 18 (5.1%) in the mc population. Especially these results demonstrate that the primers detected numerous specific fragments. Especially, the decamer primer OPC-06 generated inter-population-common DNA fragments, approximately 400 and 800 bp, respectively, in both the JJC and JUC populations. The universal primer URP-02 also generated inter-population-identical DNA fragments, approximately 350 bp and 600 bp, between the two geographical crayfish populations. Based on the average bandsharing values of all samples, the bandsharing value of individuals within the JJC population was much higher than in the JUC population. The bandsharing value between individuals no. 10 and no. 15 was 0.683, which was the highest between the two geographical populations. The dendrogram obtained by the six primers indicates two genetic clusters: cluster I (CRAYFISH 01 - CRAYFISH II), and cluster 2 (CRAYFISH 12 - CRAYFISH 22). The genetic distance between the two geographical populations ranged from 0.053 to 0.605. Ultimately, the longest genetic distance displaying significant molecular differences was found to exist between individuals in the two crayfish populations, between individuals CRAYFISH no. 02 of Jeonju and CRAYFTSH no. 15 of Jeongup (genetic distance = 0.605).

• Journal of Yeungnam Medical Science
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• 제28권2호
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• pp.105-115
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• 2011

Mercury is a toxic, persistent pollutant that bioaccumulates and biomagnifies through food webs. People are exposed to methyhnercruy mainly through their diet, especially through the consumption of freshwater and marine fish and of other animals that consume fish (e.g., marine mammals). All humans are exposed to low levels of mercury. Dietary patterns can increase exposure to a fish-eating population where the fish and seafood are contaminated with mercury. The primary toxicity targets of mercury and mercury compounds are the nervous system, kidneys, and cardiovascular system. It is generally accepted that developing organ systems are most sensitive to the toxic effects of mercury. The fetal-brain mercury levels appear to be significantly higher than the maternal-blood mercury levels, and the developing central nervous system of the fetus is currently regarded as the main system of concern as it demonstrates the greatest sensitivity. The subpopulation that may be at greater risk for mercury toxicity are those exposed to higher levels of methylmercury due to carnivorous fish, including sharks.

• 한국환경생태학회지
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• 제29권1호
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• pp.29-45
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• 2015

Water chemistry and fish community, based on fish compositions and ecological characteristics(trophic/tolerance guilds and condition factor), were compared in Gucheon Reservoir($G_cR$) and Yeoncho Reservoir($Y_cR$). Chemical parameters of water quality such as BOD, COD, nutrient(N, P) and suspended solids indicated that water quality was better in the $Y_cR$ than $G_cR$, and the temporal variability in seasonal and interannual patterns were greater in the $Y_cR$. The greater variability was mainly attributed to intense dilutions of reservoir water by Asian monsoon rain during July-August. Fish guild analysis indicated that species diversity was higher in the $G_cR$ than the $Y_cR$, and that the proportion of tolerant and omnivore species were greater in the $Y_cR$. Regression analysis of body weight-total length showed that the regression coefficient(b value) was lower in the $G_cR$(2.15 ~ 2.40) than the $Y_cR$(2.59 ~ 3.14). Condition factor(K) of fish against the total length showed negative slope of Zacco temminckii, Carassius auratus, Pseudorasbora parva and Rhinogobius brunneus population in the $G_cR$, and a positive slope of Carassius auratus and Rhinogobius brunneus population in $Y_cR$. Overall, our data suggest that the growth of the fish populations, based on the length-weight relations and condition factor, reflected the trophic regime of nutrients and organic matter.

• 대한기계학회논문집A
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• 제33권10호
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• pp.1029-1037
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• 2009

Recently, the technologies of mobile robots have been growing rapidly in the fields such as cleaning robot, explosive ordnance disposal robot, patrol robot, etc. However, the researches about the autonomous underwater robots have not been done so much, and they still remain at the low level of technology. This paper describes a model of 3-joint (4 links) fish robot type. Then we calculate the dynamic motion equation of this fish robot and use Singular Value Decomposition (SVD) method to reduce the divergence of fish robot's motion when it operates in the underwater environment. And also, we analysis response characteristic of fish robot according to the parameters of input torque function and compare characteristic of fish robot with 3 joint and fish robot with 2 joint. Next, fish robot's maximum velocity is optimized by using the combination of Hill Climbing Algorithm (HCA) and Genetic Algorithm (GA). HCA is used to generate the good initial population for GA and then use GA is used to find the optimal parameters set that give maximum propulsion power in order to make fish robot swim at the fastest velocity.

• 한국수산과학회지
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• 제54권1호
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• pp.80-89
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• 2021

In Korea, marine fish landed at ports are randomly sampled on a periodic basis (e.g., daily or weekly), and body sizes (e.g., lengths and weights) of those sampled fish are measured. The motivation for our study is whether or not such measurements reflect the size distribution, especially the length distribution of fish landed (= a population), because such length measurements are key data for a length-based assessment model. The current sampling method is to sample fish landed at ports by body size group (e.g., very small, small, medium, large, very large), using the sampling weights as the number of boxes by body size group. In this study, we showed that length composition data about fish sampled by the current method did not represent the length frequency distribution of the fish landed, and suggested that an alternative sampling method should be applied of using the sampling weights as the number of fish landed by body size group. We also introduced a method for determining an appropriate sample size.

• 한국수산과학회지
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• 제2권1호
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• pp.47-62
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• 1969

풀망둑 Synechogobius hasta(TEMMINCK et SCHLEGEL)의 식성 조사와 먹이생물 상호간의 생물학적 변화를 조사하기 위하여 낙동강 유역의 선암, 가락, 성산, 하단의 4개 지점에서 총 1,295개체의 풀망둑을 월별로 채집하였다. 위 내용물은 3가지 방법에 의해 구분하였으며, 이 방법은 수정된 Nilsson의 방법(Dahl 1962)을 다시 약간 수정하여 사용하였다(Table 2). 1) 위 내용물의 각 먹이종목별 수를 계산하여 한 계절동안 전체 풀망둑이 먹은 먹이생물의 총 개체수에 대해 Percentage를 낸 것을 Table 2에 "N"(Numerical)로 표시하였다. 2) 한 계절동안 채집한 풀망둑 수에 대한 각 먹이종목(Food Item)이 발생하는 풀망둑 수의 출혈빈도수를 Table 2에 "O"(Frequncy of Occurrence)로 표시하였다. 3) Predominant한 먹이종목을 선택하여 그것의 총 개체수에 대한 각 Predominant한 먹이수의 Percentage를 "D" (Dominance)로 표시하였다. 먹이생물은 50개의 먹이종목으로 되고 이것을 13가지의 Main Group로 나누고 (Fig. 2-1), 이것을 다시 먹이 생물을 제공하는 Habitat내의 Animal Community의 조건에 따라 Obligatory Bottom Animal, Organic Drift 와 Actively Swimming Form로 나누었다. 풀망둑의 식성은 Table 2에서 보는 것과 같이 먹이생물의 평균 $94.6\%$가 Obligatory Bottom Animal인 것으로 보아 풀망둑은 전형적인 Bottom Feeder였다. 그리고, 이들의 먹이생물은 일반적으로 이들이 살고 있는 Habitat 내의 Benthic Fauna의 Local Composition에 의해 Dominant Food Organism이 결정되고, 계절별로 먹이생물들 사이에 생물학적 상호 작용으로 인한 Seaeonal Rhythm을 나타내고 있었다. 선암 지역과 가락 지역은 동일한 먹이생물들 사이에 Habitat의 종적 구분에 의해 그 Population의 천이가 반대 현상으로 나타나는 Locality Variation을 보이며, 성산, 하단 지역은 먹이생물의 계절적 변화와 하구성 생물상이 동일한 점으로, 동일한 조건의 Habitat로 생각된다. 이상의 것을 간추려 보면, 1) 풀망둑은 주로 저생동물을 먹이로 하며, 그 먹이생물은 Habitat 내의 Food Composition에 의해 결정된다. 2) 먹이생물의 계절적 변화는 Population내의 생물학적인 변화의 상호 작용에 의해 Seasonal Rhythm을 나타낸다. 3) 풀망둑의 식성은 비편식성이고 먹이생물의 종류 변화가 많다. 4) 가장 중요한 먹이생물은 Polychaeta, Palaemon modestus, Isopoda, Gammaridea, Insecta (nymphs and larvae), Ilyoplax deschampsi, Paratye compressa로 나타난다. 5) 성산, 가락, 선암의 Community내에서 먹이생물은 종적천이 (Longitudinal Succession) 현상이 나타난다 6) 풀망둑은 수은이 상승($20^{\circ}C$이상)하는 4월경부터 하구로 이동하고, 9월부터 상류로 이동하는 Seasonal Movement를 하는 어류이다.

• 한국물환경학회지
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• 제39권4호
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• pp.329-342
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• 2023

Turbid water and suspended sediment (SS) load are having negative consequences such as water quality degradation and ecological damage, thus necessitating the establishment of management guidelines to reduce their impact. The present work investigates the spatio-temporal distribution of fish species and the effects of turbid water from 2011-2016 in the upper reaches of Soyang-Dam. The family Cyprinidae is the largest population in the study area, among which Zacco platypus and Zacco koreanus are the dominant species. The diversity of species is relatively abundant in the upper watershed, while the seasonal effect on the population distribution remains unclear. Using two main common components of the empirical orthogonal function (EOF) analysis, the distribution characteristics of 27 species at five survey sites are revealed. Zacco koreanus is found to be predominant at the upstream A-Naerincheon, while Zacco platypus and Rhinogobius brunneus are found to be predominant at the upstream B-Bukcheon. Disturbance of an aquatic ecosystem has a relatively greater impact in the downstream, as-compared to the upper area-the high proportion of forest area is decreased whereas that of agricultural and urbanized areas is increased. The patterns of representative species are changed according to the mid- to long-term effects of turbid water and SS. Accordingly, the significant correlation between the SS load and fish distribution EOF analysis indicates that it should be considered as a potential alternative that can overcome the limitations of impact assessment on turbid water to the Fish Assessment Index (FAI). A comprehensive study examining the long-term effects of SS load to the fish ecosystems with a systematic statistical analysis of sufficiently accumulated data at the national level is needed as future research.