간행물
Korean Journal of Environmental Biology KCI 등재 환경생물
- 발행기관 한국환경생물학회
- 자료유형 학술지
- 간기 계간
- ISSN 1226-9999 (Print)2287-7851 (Online)
- 수록기간 1983 ~ 2024
- 주제분류 자연과학 > 생물학 자연과학 분류의 다른 간행물
- 십진분류KDC 472DDC 570
권호리스트/논문검색
Vol. 38 No. 2 (2020년 6월) 13건
Original article
1.
2020.06
구독 인증기관 무료, 개인회원 유료
Toxic assessment of antifouling agents (diuron and irgarol) was conducted using the fertilization and the normal embryogenesis rates of the sea urchin, Mesocentrotus nudus. Bioassessment began with male and female reproductive cell induction. White or cream-colored male gametes (sperm) and yellow or orange-colored female gametes (eggs) were acquired and fully washed, separately. Then, the fertilization and normal embryogenesis rates were measured after 10 min and 48 h of exposure to the toxicants, respectively. The fertilization and embryo development rates were greater than 90% in the control, validating the suitability of both endpoints. The normal embryogenesis rates were significantly decreased with increasing concentrations of diuron and irgarol, but no changes in the fertilization rates were observed in concentrations ranging from 0 to 40 mg L-1. The EC50 values of diuron and irgarol for the normal embryogenesis rates were 20.07 mg L-1 and 22.45 mg L-1, respectively. The no observed effect concentrations (NOEC) were <1.25 mg L-1 and the lowest observed effect concentrations (LOEC) were 1.25 mg L-1 and 2.5 mg L-1, respectively. From these results, concentrations of diuron and irgarol over 1.25 mg L-1 and 2.5 mg L-1, respectively, can be considered to have toxic effects on invertebrates, including M. nudus. The ecotoxicological bioassay in this study using the noted fertilization and normal embryogenesis rates of M. nudus can be used as baseline data for the continued establishment of environmental quality standards for the effects of antifouling agents (especially diuron and irgarol) in a marine environment.
4,000원
2.
2020.06
구독 인증기관 무료, 개인회원 유료
Seung-Woo Jo, Nam Seon Kang, Jung A Lee, Kyeong Mi Kim, Hyeong Seok Jang, Moongeun Yoon, Ji Won Hong, Ho-Sung Yoon
A eukaryotic marine microalga was isolated from Jungmun Saekdal Beach, Jeju Island, Korea and an integrated approach, including molecular phylogeny and morphology, was used to determine its taxonomical status. Molecular phylogenetic evidence inferred from the small subunit (SSU) 18S rRNA sequence and internal transcribed spacer (ITS) secondary structure analysis clearly showed that the isolate belonged to the recently described species, Jaagichlorella roystonensis. Distinctive morphological keys of the species were also observed by light microscopy and scanning/ transmission electron microscopy (S/TEM). In this study, a Korean marine J. roystonensis species was described for the first time and was subsequently added to the national culture collections in Korea.
4,000원
3.
2020.06
구독 인증기관 무료, 개인회원 유료
Temperature-dependent development models for Hydrochara affinis were built to estimate the ecological parameters as fundamental research for monitoring the impact of climate change on rice paddy ecosystems in South Korea. The models predicted the number of lifecycles of H. affinis using the daily mean temperature data collected from four regions (Cheorwon, Dangjin, Buan, Haenam) in different latitudes. The developmental rate of each life stage linearly increased as the temperature rose from 18°C to 30°C. The goodness-of-fit did not significantly differ between the models of each life stage. Unlike the optimal temperature, the estimated thermal limits of development were considerably different among the models. The number of generations of H. affinis was predicted to be 3.6 in a high-latitude region (Cheorwon), while the models predicted this species to have 4.3 generations in other regions. The results of this study can be useful to provide essential information for estimating climate change effects on lifecycle variations of H. affinis and studies on biodiversity conservation in rice fields.
4,000원
4.
2020.06
구독 인증기관 무료, 개인회원 유료
The seasonal variation in the zooplankton community and hydrographic conditions were examined in three regions (inner, central, and outer regions) of Gamak Bay, Korea. Zooplankton samples were collected over a period of 12 months from January to December 2006. The hydrographical parameters of temperature, salinity, chlorophyll-a concentrations, dissolved oxygen, and chemical oxygen demand were measured. The total zooplankton density varied from 411 to 58,485 ind. m-3, with peaks in early summer. A total of 65 taxa accounted for approximately 86.9% of the annual mean zooplankton density: Noctiluca scintillans (30.9%) Paracalanus parvus s. l. (24.3%), Acartia omorii (11.9 %), Eurytemora pacifica (5.7%), cladocerans (4.1%), cirriped larvae (3.8%), Oithona similis (3.7%), and Pseudevedne tergestina (2.5%). Copepods dominated numerically throughout the year and comprised 54.3% of the total zooplankton. Most of the dominant copepods showed a well-defined seasonal pattern. The density and diversity of zooplankton in Gamak Bay were influenced by the hydrographic environment that was subject to significant spatial and temporal variations. Multivariate statistics showed that seasonal temperature was the most significant predictor of zooplankton taxa, density, and diversity, as well as the density of dominant taxa. Our results suggest that fluctuations in the zooplankton populations, particularly copepods, followed progressive increments in the temperature and COD concentrations.
5,100원
Note
5.
2020.06
구독 인증기관 무료, 개인회원 유료
The level at which analyses of DNA content might contribute more significantly to the genetic mechanisms of evolution lies in the events of speciation. The object of this study was to investigate the DNA content of abalone (Haliotis discus hannai) and determine the optimal tissue samples for measuring the DNA content of abalone by flowcytometry without fixation. The DNA content (pg/nucleus) of gill tissue (2.5±0.08), which was contaminated with protozoa, was significantly lower than that of muscle tissue (3.2±0.02), mantle tissue (3.2±0.02) (p<0.05), and a standard reference standard, while the DNA contents of muscle tissue and mantle tissue were higher than that of the standard reference. Considering the results of this study, DNA content analysis with flowcytometry is an acute and rapid method by which muscle tissue and mantle tissue are the most appropriate sample for measuring the DNA content of abalone without fixation.
4,000원
Original article
6.
2020.06
구독 인증기관 무료, 개인회원 유료
We conducted a seasonal field survey to analyze the distribution patterns of a phytoplankton community and biological oceanographic characteristics in the Geum river estuary in 2018. The results showed that the phytoplankton community consisted of 58 genera and 116 species, showing a relatively simple distribution. It was controlled by diatoms at 70.2%, a low number of species in winter and spring, and a high number in summer and autumn. The phytoplankton cell density ranged from 10.0 to 2,904.0 cells mL-1, with an average layer of 577.2 cells mL-1, which was low in autumn and high in winter. The seasonal succession of phytoplankton dominant species was mainly centric diatoms from winter to summer, including Thalassiosira nordenskioeldii, Cerataulina bergonii, and Skeletonema costatum-ls in winter, S. costatum-ls and C. bergonii in spring, and Eucampia zodiacus and Th. nordenskioeldii in summer. However, the autumn species depended upon the regions, with the inner bay dominated by the centric diatom, Aulacoseira cf. granulata, the mixed areas by S. costatum-ls, and the open sea by the dinoflagellate, Lingulodinium polyedra. According to principal component analysis (PCA), the phytoplankton community was greatly affected by the inflow and expansion of freshwater, including high nutrients, which are introduced annually through the rivermouth weir in Geum river estuary. However, the estuary, which is strongly affected by annual freshwater, was limited to areas near Geumran Island, which is adjacent to the river-mouth weir.
5,100원
7.
2020.06
구독 인증기관 무료, 개인회원 유료
Toxicities to many organs caused by humidifier disinfectants have been reported. Recently, humidifier disinfectants have been reported to cause cardiovascular, embryonic, and hepatic toxicities. This study was designed to investigate the toxic mechanism of humidifier disinfectants and compare toxicity in a cellular model and a zebrafish animal model. Because brain toxicity and skin toxicity have been less studied than other organs, we evaluated toxicity in a human dermal cell line and zebrafish under various concentrations of humidifier disinfectants that included polyhexamethyleneguanidine phosphate (PHMG), oligo-[2-(2-ethoxy)-ethoxyethylguanidinium- chloride] (PGH) and methylchloroisothiazolinone/methylisothiazolinone (CMIT/MIT). A human dermal fibroblast cell line was treated with disinfectants (0, 2, 4, 6, 8, and 16 mg L-1) to compare their cytotoxicity. The fewest PHMG-treated cells survived (up to 33%), while 49% and 40% of the PGH- and CMIT/MIT-treated cells, respectively, survived. The quantification of oxidized species in the media revealed that the PHMGtreated cells had the highest MDA content of around 28 nM, while the PGH- and CMIT/ MIT-treated cells had 13 and 21 nM MDA, respectively. As for brain toxicity, treatment of the zebrafish tank water with CMIT/MIT (final 40 mg L-1) for 30 min resulted in a 17- fold higher production of reactive oxygen species (ROS) than in the control. Treatment with PGH or PHMG (final 40 mg L-1) resulted in 15- and 11-fold higher production, respectively. The humidifier disinfectants (PHMG, PGH, and CMIT/MIT) showed severe dermal cell toxicity and brain toxicity. These toxicities may be relevant factors in understanding why some children have language disorders, motor delays, and developmental delays from exposure to humidifier disinfectants.
4,000원
8.
2020.06
구독 인증기관 무료, 개인회원 유료
Rhodomonas salina is a phototrophic marine flagellate. We examined the ultrastructure of R. salina with particular attention to the flagellar apparatus by transmission electron microscopy and compared it with that of other cryptomonads reported previously. The major components of the flagellar apparatus in R. salina were a keeled rhizostyle (Rhs), a striated fibrous root (SR), a SR-associated microtubular root (SRm), a mitochondrion-associated lamella (ML), and three types of microtubular roots (9r, 4r, and 2r). The keeled Rhs originated near the proximal end of the dorsal basal body, passed near the nucleus and dissociated at the posterior end of the cell. The SR and SRm originated between two basal bodies and laterally extended to the right side of the cell. The ML originated between two basal bodies and extended to the left side of the cell. The 9r originated between the ventral basal body and the Rhs and extended toward the anterior dorsal lobe of the cell. The 4r originated near the 9r and extended toward the dorsal lobe with the 2r, which originated between two basal bodies. Here, the flagellar apparatus in R. salina is described, and the ultrastructure of the flagellar apparatus is compared among cryptomonad species.
4,200원
9.
2020.06
구독 인증기관 무료, 개인회원 유료
As part of the research program “2018 Rapid screening and identification of freshwater microorganisms using MALDI-TOF/MS library” freshwater samples were collected from a branch of the Nakdong River. Almost 300 antibiotic-resistant bacterial strains were isolated from freshwater samples and subsequently identified by 16S rRNA gene sequencing. Seventeen strains among the isolates shared high 16S rRNA gene sequence similarity (>99.0%) with known species that were not previously recorded in Korea, and each of the isolates also formed a robust phylogenetic clade with the closest species. These species were phylogenetically diverse, belonging to four phyla, seven classes, 10 orders, and 13 genera. At the genus and class level, the previously unrecorded species belonged to Rhodovarius, Xanthobacter, and Shinella of the class Alphaproteobacteria; Ottowia, Simplicispira, and Zoogloea of Betaproteobacteria; Pseudomonas, Acinetobacter, and Shewanella of Gammaproteobacteria; Arcobacter of Epsilonproteobacteria; Sphingobacterium of Sphingobacteriia; Trichococcus of Bacilli; and Leucobacter of Actinobacteria. The previously unrecorded species were further characterized by examining their gram-staining, colony and cell morphology, biochemical properties, and phylogenetic position.
4,000원
10.
2020.06
구독 인증기관 무료, 개인회원 유료
This study reported on the phytoplankton community and seasonal changes in the Seoul passage section and downstream in the Han River in 2012. Field samples were collected monthly from the upper (Paldang), middle (Cheongdam), and downstream (Seongsan) areas of the Seoul passage section. Water temperature, DO, pH, and conductivity were measured at each station. All environmental factors measured were recorded similarly at the three stations. The water temperature ranged from 2 to 30°C and the dissolved oxygen ranged from 4.8 to 9.1 mg L-1, showing typical patterns of temperate regions. The phytoplankton cell concentrations ranged from 990 cells mL-1 (Paldang, December) to 2.9×104 cells mL-1 (Seongsan, March), and the chlorophyll-a content showed similar patterns to the cell numbers. The phytoplankton community was comprised of 75 genera and 95 species, including 37 diatoms, 29 Chlorophyta, 11 cyanobacteria, and two dinoflagellates. The number of species that appeared seasonally varied greatly, from nine species (Paldang, May) to 35 species (Cheongdam, December). Diatoms were the most dominant in all stations and seasons, except in summer. In contrast, chlorophytes and cyanobacteria showed sporadic high numbers in the summer and fall seasons. Four diatoms Stephanodiscus hantzschii f. tenuis, S. hantzschii, Fragilaria sp., and Aulacoseira spp., a chlorophyte Actinastrum hantzschii, and a cyanobacterium Microcystis sp. were each present in proportions greater than 10%. This study provides fundamental data from phytoplankton communities and environmental factors in the Han River for understanding water quality for long-term environmental monitoring.
4,000원
Note
11.
2020.06
구독 인증기관 무료, 개인회원 유료
The Nannophya species in Korea was thought to consist of only Nannophya pygmaea. Previous studies on the species, including life history and development, conservation and restoration, habitat characteristics, genetic studies, distribution, behavior, and taxonomy have been conducted. However, a new Nannophya species, Nannophya koreana, was recently discovered in Korea. Moreover, this new species was found to inhabit both Korea and Japan. Thus, the previous studies should be reevaluated in relation to the new species, Nannophya koreana, and the latter should be treated as an endangered species worldwide given the current population instability.
4,000원
12.
2020.06
구독 인증기관 무료, 개인회원 유료
A 210-day experiment was conducted to examine the effects of starvation on survival, the gonadosomatic index (GSI), hepatosomatic index (HSI), and the intestinosomatic index (ISI), and histological changes in the renal tubule epithelium, midgut epithelium, and hepatocytes in Far Eastern catfish (Silurus asotus). The survival rate decreased to 92.2±0.47% in the fed group and 74.4±2.59% in the starved group during the 210-day experimental period. GSI, HSI, and ISI were lowest in the starved group (p<0.05). The hepatocyte nuclear area, hepatocyte cell area, the nuclear height of the midgut epithelium, and the nuclear height of the kidney were highest in the fed group (p<0.05). The hepatocyte nuclear area, nuclear height of the midgut epithelium, and nuclear height of the kidney were lowest in the starved group (p<0.05). The numbers of melano-macrophages (MMs) found in the kidney cells increased during starvation in this species. This suggests that thinner body cavity regions, the contraction of hepatocyte nuclear sites, and the spreading of kidney cell MMs in this species could be used as alternative indicators for identifying starvation conditions. Therefore, the results from our study provide accurate indications of the nutritional status of Far Eastern catfish.
4,000원
13.
2020.06
구독 인증기관 무료, 개인회원 유료
The method of natural spawning is very passive and inconvenient for the study of developmental engineering in marine medaka, Oryzias dancena. The optimum concentration of human chorionic gonadotropin (HCG) and carp pituitary extract (CPE) for ovulation and spawning, and the injection time for the artificial spawning of marine medaka were analyzed in this study. The success rate, survival rate, and hatching rate were highest with 100 IU HCG kg-1 BW and 5 mg CPE L-1 in both male and female marine medaka (p<0.05). After obtaining unfertilized eggs and sperm by the injection of HCG and CPE into the broodstock of marine medaka, artificial fertilization could be successfully achieved any time fertilized eggs are needed in this species. This result should be useful for developing a study program for marine medaka as an experimental animal.
4,000원
