To assess the accuracy of species delimitation in the genus Aphaenomurus Yosii, we conducted a comparative micro-morphological study and molecular analysis using two mitochondrial (COI, 16S) and two nuclear genes (18S, 28S) on 118 specimens from 24 localities. The results showed that the morphological characters of A. vicinus and A. interpositus, as presented in the original description, were intermixed in phylogenetic lineages within the genus and did not form independent lineages. Furthermore, there were enough differences among Aphaenomurus individuals to be considered as morphologically distinct species (Th. III is 1+1 or 2+2, Abd. I is 2+2 or 3+3, Abd. II is 2+2 or 3+3), but they do not form an independent lineage. Molecular and morphological analyses have determined that A. vicinus and A. interpositus are the same species, exhibiting morphological variation in dental spines formula, claws, chaetotaxy, and other features. Additionally, the genus Aphaenomurus forms a monophyletic clade, which is further divided into several lineages within the genus. No morphological differences were observed to distinguish these lineages. This cladistic divergence is attributed to heteroplasmy, which is supported by previous studies that have suggested the possibility and problems of heteroplasmy in Collembola, and by the high genetic distances between individuals in the mitochondrial genes of Aphaenomurus.
본 연구의 목적은 질산, 황산, 암모니아수, 과산화수소에 대한 생태독성평가를 통해서 사고대비물질들에 대한 기초 독성 데이터베이스를 구축하여, 향후 화학사고 발생시 환경 피해에 관한 의사결정에 과학적 근거를 제공하는 데 있다. 이를 위해 본 연구에서는 사고대비물질 중 토양의 물리·화학적 성질을 변화시킬 수 있는 질산, 황산, 암모니아수, 과산화수소를 대상으로 국내 토착 절지동물인 김어리 톡토기 (Paronychiurus kimi)를 이용한 생태독성평가를 수행하였다. 7일간의 급성독성평가와 28일간의 만성독성평가를 수행하였으며, 시험물질 농도에 따른 토양의 pH 변화를 관찰하였다. 토양의 pH는 질산, 황산, 과산화수소, 암모니아수의 농도가 10,000 mg kg-1 soil dry wt.일 때, 각각 2.86, 2.72, 7.18, 9.69이었다. 질산, 황산, 과산화수소, 암모니아수에 대한 만성독성평가 결과, LC50 값은 각각 2,703, 5,414, 3,158, 859 mg kg-1 soil dry wt.이었으며, P. kimi의 산란 수에 대한 EC50 값은 각각 587, 2,148, 1,300, 216 mg kg-1 soil dry wt.이었다. 비록 본 연구에서는 사고대비물질들의 유입에 따른 토양 pH의 변화만이 조사되었지만, 본 연구의 결과는 P. kimi가 사고대비물질에 의해 변화된 토양의 pH뿐만 아니라 사고대비물질의 유입에 의해 감소된 유기물 함량과 생성된 반응 산물에 의해서도 사망률과 산란수에 영향을 받을 수 있음을 의미한다. 대부분의 사고대비물질들이 토양의 특성을 변화시킬 수 있다는 점을 감안할 때, 토양의 특성 변화와 이에 따른 생물 영향을 고려한 화학사고 후 평가 및 복원 방법이 필요하다.
The purpose of this study was to investigate the toxic effects of zinc in collembolan Paronychiurus kimi at the individual (survival and juvenile production) and population (population growth and age structure) levels after 28 days of exposure in artificially spiked soil. These toxic effects were interpreted in conjunction with the internal zinc concentrations in P. kimi. The EC50 value for juvenile production based on the total zinc concentration was 457 mg Zn kg-1 dry soil, while the LC50 value for adult survival and ri=0 value for population growth were within the same order of magnitude (2,623 and 1,637 mg Zn kg-1 dry soil, respectively). Significant differences in adult survival, juvenile production, and population growth compared with the control group were found at concentrations of 1,500, 375, and 375 mg Zn kg-1 dry or higher, respectively, whereas significant differences in the age structure, determined by the proportion of each age group in the population, were observed in all treatment groups. It appeared that the internal zinc level in P. kimi was regulated to some extent at soil zinc concentrations of ≤375 mg Zn kg-1 dry soil, but not at high soil zinc concentrations. These results indicate that, despite zinc being regulated by P. kimi, excess zinc exceeding the regulatory capacity of P. kimi can trigger changes in the responses at the individual and population levels. Given that population dynamics are affected not only by individual level but also by population level endpoints, it is concluded that the toxic effects of pollutants should be assessed at various levels.
In this study, Folsomia octoculata and Folsomia quadrioculata which is common and representative Collembola species in temperate forests of Korea, were selected as potential bioindicator species. Through three years of survey of the density of the two Folsomia species and environmental factors of the sampling sites, the distribution and habitat preference of the two Folsomia species was investigated. The habitats of the two species were highly distinguished, mainly due to differences in preference for temperature, organic matter content, pH, available phosphorus. In addition, these two-species showed different preferences for vegetation. F. quadrioculata and F. octoculata were mainly found in habitat which Quercus and Pinus sp. live, respectively. This is because the distributions of two tree species are the result of interaction with temperature, available phosphoric acid, and soil organic matter content.
Acute and chronic toxicities of methyl ethyl ketone and methanol were investigated on Paronychiurus kimi (Collembola), for evaluating the potential effects of accidental exposures of these chemical substances on the terrestrial environments. This study was undertaken to establish a toxicity database for these chemical substances, which was required for the preparation of the response compensation and liability act for agricultural production and environmental damage. The 7-d acute toxicity and 28-d chronic toxicity were conducted using the OECD artificial soil spiked with varying, serially diluted concentrations of methyl ethyl ketone and methanol. Mortality was recorded after 7-d and 28-d of exposures, and the number of juveniles were determined after 28-d of exposure in the chronic toxicity test. In both assessments, methanol was more toxic than methyl ethyl ketone in terms of mortality (LC50) and reproduction (EC50). The 7-d LC50 of methyl ethyl ketone and methanol were 762 and 2378 mg kg-1 soil dry wt., respectively, and the 28-d LC50s were 6063 and 1857 mg kg-1 soil dry wt., respectively. The 28-d EC50 of methyl ethyl ketone and methanol were 265 and 602 mg kg-1 soil dry wt., respectively. Comparison of results obtained in this study with literature data revealed that P. kimi was more sensitive to methanol than other soil invertebrates. However, given the high volatility of the chemicals tested in this study, further studies are necessary to improve the current test guideline, or to develop new test guidelines for an accurate assessment of chemicals that require toxicity databases for chemical accidents.
To assess the temperature change effects on Collembola communities, we selected 9 Korean mountains in different latitudes. Top soil was collected and Collembola extracted from 3 sites in different elevation in each mountain. Extracted Collembola were sorted to genera and this data were summarized as total abundance, family richness and diversity. Additionally, soil temperature in each plot, physical and chemical properties of the soil was investigated and that correlated with Collembola community data. Average soil temperature and soil properties affected patterns in Collembola abundance and family richness. The results indicate that temperature change and soil properties strongly affected Collembola communities. Therefore, Climate change has high potential to affect Collembola communities.
Estimating compensation payment for environmental damages by chemical accidents has been controversial because accurate quantification of damages of chemical accident is so complicated and there is lack of scientific studies about impact of chemical accidents. In this study, for supporting chemical accidents compensation criteria, the 7 days acute and 28 days chronic toxicity test was conducted with 4 major chemical accident substances (Sulfuric acid, Nitric acid, Methanol and Methylethylketone) according to the OECD 232 guidelines. Methylethylketone was most toxic chemical followed by methanol, nitric acid and surfuric acid. Further study of comparison between pH and chemical effects was needed.
A new species of the cave-dwelling springtail Lethemurus coreanus Chang and Bae, sp. n. is described from Korea. Lethemurus coreanus can be distinguished from congeners by the spinelike setae on the tibiotarsus, numbers of dental spines, number of setae on the trochanteral organ, and body macrochaetae chaetotaxy. A key to the species of Lethemurus is provided.
Toxicity test of contaminate soil is very complex because of differential bioavailability in the soil. Therefore, bioavailability of metals in soil is a major factor influencing estimates of toxicity. In this study, the two major test was conducted. First, the toxicity of arsenic for the Collembola, Paronychiurus kimi, was assessed by determining the effects of increasing arsenic concentration on survival, reproduction and body concentration of As in five forested soils with different available phosphate and oxide-metal concentration. Second, the sequential extraction procedure (SEP) for arsenic by choosing extraction reagents commonly used for sequential extraction of metals was tested. The EC50 based on total As concentration in soil was estimated respectively. The available phosphate and oxide-metal concentration in soil influenced on As fraction in soil. Especially, As in soil which is non specifically and specifically sorbed (fraction 1, 2) has strong correlation with available phosphate and oxide-metal concentration (p<0.05). The toxicity is more higher in the soil with high available phosphate and low oxide-metal concentration. In addition, the high arsenic concentration in fraction which is amorphous and poor-crystalline hydrous oxide of Fe and Al (fraction 3) had effect to the toxicity. As a result, the toxicity of As is related with As concentration in fraction 1, 2 and 3 and the soil properties and the arsenic fractionation in soil have a influence on the bioavailability and toxicity.
Climate change is a global phenomenon and has major impacts on ecotoxicology. A variety of environmental variables affected by climate change can alter the fate of chemical and responses of organism. Especially, soil temperature is an important factor in ecotoxicology. Increasing temperature results in an increase in the rate of uptake and degradation of toxic compound. Therefore, the research of temperature effect on toxicity is needed to understand the change of toxic effect under climate change.
In this regards, the response of Paronychiurus kimi (Collembola) to Geunsami™ (glyphosate-based herbicide) were evaluated at different temperatures (20℃, 25℃) and soil aging time (7, 15 days). Survived adults and hatched juveniles were counted after 28-day exposures in artificial soil spiked with 1, 5, 50, 100, 500 mg/kg of glyphosate in different temperature and soil aging time conditions. In addition, we investigated the fatty acid composition of Paronychiurus kimi.
Increasing soil aging time and temperature, EC20 value of P. kimi was increased. Fatty acid composition of P. kimi was similar with that of Folsomia candida mainly composed of 18:1 w9c, 16:0 and 18:0 fatty acids. UI (Unsaturation Index) and the ratio C16/18 of fatty acid composition decreased with increasing temperature. The 18:0 (Stearic acid) fatty acid increased with increasing concentration of glyphosate.
A new species of the genus Onychiurus is described from Korea(Jeoksang Mountain in Muju). The genus Onychiurus was elected by Gervais in 1841 with type species Podura ambulans Linneus, 1758. 49 specis of Onychiurus have been reported worldwide, of which only one species, O. polychaetosus, have been recorded from Korea. This genus is characterized by postantennal organ with compound vesicles, antennal Ⅲ sense organ with 2 sensory clubs, furca reduced to a small area of fine ganulation with 2+2 posterior setulae arranged in a row, seta d0 on a head and anal spines present. Onychiurus sp.1 is characterized by the peculiar distribution of dorsal (32/0,2-3,2-3/33333) and ventral (1/000/0101) pseudocelli that allow to distinguish it from the other congeneric species. Antennal segment Ⅲ with four guard setae, two sensory rods, two bent and granulated sensory clubs and five papillae irregular in shape. Postantennal organ consists of 10-12 finely granulated vesicles and tibiotarsi with distal whorl composed of nine setae.
The genus Xenylla Tullberg in the family Hypogastruridae is cosmopolitan, containing about 131 species at present in the world. However, the genus Xenylla of Asia has been very poorly investigated; in Japan, four species, X. acauda Gisin, X. arenosa Uchida & Tamura, X. brevispina Kinoshita, and X. longicauda Folsom, were recorded, only three species, X. boerneri Axelson, X. changlingensis Wu and Yin, and X. changchunensis Wu and Yin, was known to occur in China. In Korea, the first recognizable species of the genus Xenylla was only one listed by Lee in 1973: Xenylla brevispina Kinoshita, 1916. Later Park et al (2005) added four new species, X. convexopyga, X. dotata, X. longistriata, and X. marina, which collected from litter of coniferous and broad-leaved trees, soil layer of a deciduous forest and dry accumulated organic matter on the margins of saline water. One new species of the genus Xenylla that were found from Korea is found. The new species characterized by labral setae arrangement and tiny anal spines. The present species resembles X. dotata in the arrangement of dorsal and ventral setae. But it is easily distinguished from X. dotata by the length ratio of furca, morphology of mandible, the shape of dorsal setae upon fourth antennal segment, and the length of anal spine. As result of this study, Korean faunal list of Xenylla adds up to 6 species.
Cave-dwelling springtail studies in Korea initiated during 1960s by the Japanese Collembola researcher, R. Yosii, and comprehensive taxonomic studies on Korean Collembola were conducted by B. H. Lee during 1970-1990s wherein the new family Gulgastruridae was established using the type species Gulgastrura reticulosa from the Gossidonggul cave in Gangwon-do, South Korea. Eight families of cave-dwelling Collembola are known in Korea, and the family Tomoceridae is the most abundant and diverse group of cave-dwelling Collembola with 11 known species belonging to 4 genera in Korea. In this study, 12 species of Korean Tomoceridae are reviewed, and 1 new species from the genus Plutomurus and 2 new species from the genus Tomocerus are described.
A new collembolan species (Paranura rosea) which was native to Korea was selected for evaluating the effect of temperature on their biology. Development, and reproduction of P. rosea were investigated at 15, 20, 25 and 30℃ Hatchability of egg was not affected by experimental temperature, and the lower threshold temperature for development of P. rosea was estimated to be 7.53℃. The temperature reduced the juvenile and adult (maturity period). The intrinsic rate of natural increase and finite rate of increase per week at 20℃ which are maximum values showed significant difference with other experimental temperatures. Survival rate, cumulative reproduction and head capsule width was fitted by several models. Especially, the model which fitted for estimating head capsule width was used to determine their life stage. Estimated head capsule width of P. rosea at the initial oviposition varied with temperature from 0.36 ± 0.007 to 0.45 ± 0.007 with maximum at 20℃ and minimum at 30℃, and significant difference was observed at all the experimental temperature (P<0.05). However, estimated head capsule width at the last oviposition showed different statistically result at only 30℃. Molting frequency per week of one P. rosea was increased as the temperature increased. Based on this study, temperature greatly influenced on their life stage and reproduction. Therefore, relationship between temperature and P. rosea is very important for understanding their biology.