• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.29 no.3
• /
• pp.320-331
• /
• 1996

Electrophoretic comparisons of 482 individuals of Todarodes pacificus from 9 fishing areas were made to estimate genetic variability and differentiation using 17 enzymes. Strong activities were shown by 9 enzymes with 11 gene loci. The 9 sample lots could be divided into 3 genetic groups, based on dendrogram analysis using the Nei's genetic distance. The Summer, Autumn and Winter cohorts were identified as three seperated ecological populations which maintain genetic exchange. It is postulated that either the Summer cohort or the Autumn cohort has indepenently developed a local population that was isolated by hydrographic factors.

• Korean Journal of Environment and Ecology
• /
• v.21 no.6
• /
• pp.461-467
• /
• 2007

The research on food habits of the Fire-bellied toad, Bombina orientalis, distributed in Korea was done targeting a total of 487 individuals in 4 inland areas and 8 areas of Jeju island from April 1990 to September 1992. The survey results showed that there was no difference In the number of the preys of the Korean Fire-bellied per individual between the inland areas and Jeju island and the toad preyed on 1 to 3 individuals on an average, but there happened a case where some Fire-bellied toads in Jeju preyed on as much as 94 individuals. There were 13 orders surveyed in the kinds of prey of the Fire-bellied toad inland, and 10 in Jeju island with a high predation frequency and the number of the preyed individuals of Coleoptera and Hymenoptera. The predation frequency of the two populations was similar in terms of prey taxa, but there appealed a different aspect in the number of the individuals by prey taxa. In short, the inland population of Fire-bellied toad was found to eat more various sorts of preys, not satisfied with limited sorts of preys in comparison with the Jeju toad. There appeared a difference in eating habits by month between the two populations; the feeding duration of the inland population was from May to October, but the Jeju population was from April to September. Among the kinds of prey taxa, Coleoptera and Hymenoptera were equally distributed to the two populations of Korean Fire-bellied toad for this research purpose during the survey period. The number of orders, predation frequency and the number of the prey taxa by one population prey were rather higher in the summer. Therefore, it is concluded that the most active period of predation of the Korean Fire-bellied toad is summer.

• The Korean Journal of Zoology
• /
• v.31 no.4
• /
• pp.327-333
• /
• 1988

계절에 따른 초파리 집단내 역위다형 현상의 변동상을 알기 위하여 전주근교의 과수원에서 1983년 1월부터 11월까지 격월로 여섯번 채집한 집단 표본을 분석하였다. 총 1071마리에서 얻은 15개형의 역위는 모두 편동원체역위(paracentric inversion)였으며, 이 중 7개형은 세계형91위(cosmopolitan inversion)였고, 나머지 8개형은 지역형역위(endemic inversion)였다. 개체당 역위의 평균 보유수는 0.639이고 역위를 보유한 개체의 빈도는 0.465였다. 7개의 세계형역위에 대한 표본집단을 분석한 결과 격월 집단간에서 유의한 차이를 보이는 반면 1월과 1 1월 표본간에서는 그 성황이 오히려 비숫해짐으로서 집단내 총역위빈도는 주기적으로 변동하고 있음이 암시된다. 역위와 환경변수와의 다중상관분석에서는 기온, 습도, 강수량이 역위빈도에 유의한 영향을 미치는 것으로 나타났고 역위 중 In(2L)t가 상기한 환경변수 모두에 대하여 유의한 상관관계를 보인 반면, In(3R)C와 In(3R)P는 어느 것과도 상관성을 보이지 않았다. 염색체내 그리고 염색체간의 연관 또는 조합의 검정결과 연관불평형혈상을 1월, 5월, 그리고 7월 표본의 제3염색체에서, 그리고 비균일조합은 1월과 7월 표본에서 역시 제3염색체에서만 산출 되었다. Seasonal changes of inversion frequencies in Chonju 0. melanogaster populations were studied. A total of 1071 males were collected six times with ho months intewal from January through November in 1983. to analyse diploid sets of chromosomes carried by males, each male was mated to several virgin females homoBvgous for cytologically standard sequence in all chromo-somes. From each mating, more than seven FL larvae were selected in random and tested to find chromosomal aberrations. In the present study, 15 different inversions were found and identified to be paracentric only In both second and third chromosomes; seven were cosmopolitan and the rest eight endemic types. The average frequency of inversions was 0.465 and the mean number of inversions carried by a single male was 0.639. The linkage disequilibria were detected between the leK and right arms of third chromosomes from the samples of January, May and Julv, Whereas nonrandom associations appeared also in the third chromosomes only in January and Julv samples. In multiple regression analysis among frequencies of inversions and environ-mental variables it appeared that mean temperature, relative humidity and total precipitation for a month skipped over 30 days before collected affect to change to frequencies of particular inver-sions. With respect to the behavior of inversions in the present samples, it is suggested, with the Friedman's analysis of variance by ranks of inversion frequency orders, that the frequencies of inversions change cyclically year to year.

• Korean Journal of Ichthyology
• /
• v.32 no.2
• /
• pp.55-62
• /
• 2020

The Relative weight index is an index for evaluating nutritional condition of fish by calculating a ratio of observed weight to standard weight. The purpose of this study is estimating standard Length-Weight relationships (standard LWRs) to calculate standard weight for application of relative weight index and analyze frequency distribution of relative weight index of 10 freshwater fish in the South Korea. The standard LWRs for each species was calculated by the Length-Weight data sets from 798 times of captures at 141 sites. The correlation of determination (r²) for all species was over 0.9 and values of parameter b were within the expected range according to Froese (2006). We calculated in increments of 10 from 10 to 90 percentile of relative weight index for each species, and it could be used as a standard for quantitative assessment of nutritional condition of freshwater fish.

• The Korean Journal of Mycology
• /
• v.20 no.3
• /
• pp.204-215
• /
• 1992

From 12 August to 21 November in 1991, 65 soil specimens were collected from nineteen leguminous plant roots throughout nine locations of four provinces. They were sieved to collect and identify the arbuscular mycorrhizal spores (four genera, 21 species). The species of Glomus were most commonly (47.6% of all observations) found, but the species of Gigaspora (about 4.8% of all observations) occurred infrequently or rarely rather than the species of the other genera. The most common arbuscular mycorrhizal species at nine locations were Acaulospora laevis and Glomus laminated spores cf. macrocarpus var. macrocarpus. All of nineteen legume plant species collected were found to be associated with the arbuscular mycorrhizal fungi . Cassia mimosoides var. nomame and Kummerowia striata in legume plants had the great frequency of arbuscular mycorrhizal fungi associated with their roots. The number of isolated spores were ranged from 0.3 to 10.0 spores per 10g of soil. The species diversity of arbuscular mycorrhizal spores at the disturbed areas were calculated to be bigger than those in the natural vegetation areas.

• The Korean Journal of Zoology
• /
• v.33 no.1
• /
• pp.6-11
• /
• 1990

Analysis of genetic structure in Kimpo natural population of Drosophila was carried out by utilizing the deleterious gene on the second chromosome of Drosophila melanogaster. Male flies tested were continuously collected for eight years; in late September 1974 and 1981-1987. The frequency of deleterious gene (lethal plus semilethal) ranged from 27.02% in 1983 to 41.48% in 1987, and the values estimated from the eight years samples are highly signihcent from each other with a homogenety test (X$^2$=52.0157, d.f.=28, P<0.005). Allelic rates ranged from 1.30% in 1981 to 5.03% in 1974. And the effective population size by using the rate of allelism was estimated average at 3, 300 pairs. Elimination rate by homozygous of lethal gene ranged from 0.0004 in 1984 to 0.0019 in 1974, and that is for smaller than mutation rate(0.005) at second chromosome. We suppose that stable frequency (about 20%) lethal genes of D. melanogaster in Kimpo natual population are maintained by invade of P-type mutator factor (P element) versus eliminated in heterozygous and homozygous condition of lethal gene.

• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.1 no.1
• /
• pp.31-43
• /
• 1968

1. Shell height frequencies of the fresh-water cockle, Corbicula elatior, sampled in the period of 1960 to 1963, are analyzed to assess the age composition and average growth pattern. Cumulative frequencies in a sample are traced on a probability scale, and the points of inflection on a probability graph are assumed to dissect age groups. 2. Seasonal growth of Corbicula elatior in the Naktong River ill as follows: Young cockles settle down on river-bed by June and grow rapidly during the summer season, reaching 14mm in shell height by October. From October to April the growth is very slow. The rapid growth in the second year starts around in May. 3. Survival rate per year for Corbicula elatior in the Naktong River is estimated to be $5\~10\%$ by age composition.

• The Korean Journal of Mycology
• /
• v.46 no.4
• /
• pp.427-435
• /
• 2018

In this study, endophytic fungi were isolated from the surface-sterilized roots of Calanthe discolor and Cephalanthera longibracteata collected from the Chungnam, Jeju, Kyungnam and Chungbuk provinces in Korea. The morphological characteristics of the obtained isolates were examined and their sequences of the internal transcribed spacer (ITS) rDNA region were analyzed using the ITS1F and ITS4 primers for species identification. Leptodontidium orchidcola showed the highest species abundance and frequency among the isolated endophytic fungi. Additionally, the community analysis revealed a high specificity between the host plants and the endophytic fungal species.

• Korean Journal of Environmental Biology
• /
• v.39 no.1
• /
• pp.108-118
• /
• 2021

The purpose of this study was to provide baseline ecological data for the conservation of the Manchurian trout habitat through the investigation of the growth status of Brachymystax lenok tsinlingensis, and Pearson's correlation analysis (PCA) between the B. lenok tsinlingensis population and the use of the land around Gyebangcheon stream. Sampling was conducted twice in July, September, and October 2018. During the July and September surveys, 882 individuals belonging to 13 species from six families were collected. The dominant species was Rhynchocypris kumgangensis and the subdominant species was Zacco koreanus. The total number of B. lenok tsinlingensis collected was 99. The results of the length-weight relationship in the B. lenok tsinlingensis population were analyzed with a regression coefficient b value of 3.1272 and a condition factor (k) value of 0.0006. Therefore, the growth condition of B. lenok tsinlingensis was regarded as fairly good. The QHEI(Qualitative habitat evaluation index) value in the B. lenok tsinlingensis habitat was 119.5(±0.5)-153.5(±0.5), indicating optimal-suboptimal conditions. As a result of the HIS (Habitat suitability index) analysis, it was confirmed that the optimal habitat for B. lenok tsinlingensis was 0.45-0.55m and >1 m in water depth, 0.55-0.65 m s^-1 in water velocity, and boulder in the substrate. The ratio of the land use in this study site was analyzed as 66.26-96.31% for forest and grassland areas, 0.00-23.79% for agricultural areas, 0.00-4.19% for urbanized areas, and 3.69-8.87% for others. Correlation analysis of the number of B. lenok tsinlingensis and various factors revealed statistically significant correlations between QHEI and forest and grassland areas, agricultural areas, and urbanized areas.

• Korean Journal of Environment and Ecology
• /
• v.30 no.4
• /
• pp.745-750
• /
• 2016

Morphological characteristics and population characteristics of the Rhynchocypris kumgangensis were investigated at Taehwa River from April 2014 to April 2015. This is the first record on R. kumgangensis not only from Guksu stream (the upstream region of Taehwa River, Ulsan-si Ulchu-gun Beomseo-eup Kuksu-ri) but also from the stream flowing into the Gangneungnamdae stream, in the southern part of East Sea, Korea. The morphometric characteristics of R. kumgangensis in the Taehwa River and the Han River are very similar except that the population at Taehwa River showed shorter caudal peduncle length than caudal peduncle depth when compared with the population at Han River. In terms of meristic character the population at Taehwa River showed fewer numbers of scales at the lateral line, above the lateral line and below the lateral line. Other than that, the two populations showed the same meristic characters. The fish cohabiting with R. kumgangensis mainly composed of Zacco platypus (25.2%), Rhynchocypris oxycephalus (24.1%) and Zacco koreanus (21.8%). Length frequency distribution analysis indicated that the length of the group ranged between 45~65 mm and the average length was 54.3 mm. Calculation of the length-weight relation of R. kumgangensis showed the value of constant a as 0.000002 and b as 3.34, and the Condition factor (K) was 1.10 an on average.