• 한국물환경학회지
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• 제22권2호
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• pp.300-307
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• 2006

The combined SHARON (Single reactor system for High ammonium Removal Over Nitrite)-ANAMMOX (Anaerobic ammonium oxidation) reactor were operated in mesophilic condition ($35^{\circ}C$). In this study, microbial granulation and characteristics of SHARON and ANAMMOX sludges were investigated using settling test, Scanning Electron Microscopy (SEM) and Fluorescence In Situ Hybridization (FISH). In SHARON reactor, Aerobic granulation with diameter of 1.5~2.5 mm was accomplished but aerobic granulation was weaker than anaerobic granular sludge. Initial seed sludge of ANAMMOX reactor was used as attached media for biofilm growth. ANAMMOX sludge was more compact and rounder rather than seed sludge. Though ANAMMOX sludge has high activity, it has lower settling ability than the seed granule. The color of ANAMMOX sludge was changed from dark to redish brown granular with diameter of 1~2 mm. In FISH of ANAMMOX sludge, high fraction of Candidatus B. stuttgartiensis which paid great role of nitrogen conversion was detected. Also, FISH results reveals that ANAMMOX bacteria inhabit at inner parts near surface, having advantages in utilization of substrates and protection from oxygen inhibition.

• Animal Systematics, Evolution and Diversity
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• 제32권2호
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• pp.105-111
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• 2016

The genetic structure of marine animals that inhabit the seashore is affected by numerous factors. Of these, gene flow and natural selection during recruitment have strong influences on the genetic structure of seashore-dwelling species that have larval periods. Relative contributions of these two factors to the genetic structure of marine species would be determined mainly by the duration of larval stage. The relationship between larval period and genetic structure of population has been rarely studied in Korea. In this study, genetic variations of cytochrome oxidase subunit I (COI) were analyzed in two dominant species on rocky shore habitats in the Korean peninsula: periwinkle Littorina brevicula and acorn barnacle Fistulobalanus albicostatus. Both species are not strongly structured and may have experienced recent population expansion. Unlike periwinkle, however, barnacle populations have considerable genetic variation, and show a bimodal pattern of mismatch distribution. These results suggest that barnacle populations are more affected by local adaptation rather than gene flow via larval migration. The bimodal patterns of barnacle populations observed in mismatch distribution plots imply that they may have experienced secondary contact. Further studies on seashore-dwelling species are expected to be useful in understanding the evolution of the coastal ecosystem around Korean waters.

• 한국발생생물학회지:발생과생식
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• 제18권4호
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• pp.241-249
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• 2014

Hyphessobrycon eques is a famous fish for ornamental fish market and aquarium. They are inhabit in regions of Amazon and Paraguay River basin. Serpae fishs were investigated 2-3 males are chased to female, and then males attempted to simulate the females abdomen. After fertilization, eggs were kept in incubators at $28^{\circ}C$. The fertilized eggs had adhesive and demesal characteristics and had a mean diameter of $0.92{\pm}0.01mm$. Larvae hatched at 16 hrs post fertilization. The hatched larvae averaged $2.90{\pm}0.16mm$ in total length ($L_T$). Complete yolk sac resorption and mouth opening occurred on the third day post hatching. At 45 days post hatching, the larvae were $12.5{\pm}1.60mm$ $L_T$ and had reached the juvenile stage.

• 수산해양기술연구
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• 제55권4호
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• pp.363-371
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• 2019

Thousands of demersal fishes inhabit in the waters around Korea and most of them are overexploited. One of reasons is technological development, which increases the efficiency of the vessels continuously. The analysis was conducted to identify the change of fishing power index to develop the vessel and gear technology that may have improved the fishing efficiency of the Danish seine fishery from 1960s to 2010s. Gross tonnage was decreased stably, but the horse power was increased annually. The length of ground rope, warp and hand rope was somewhat longer, but changed a little. Color fish finder was utilized from the mid-1960s and positioning system was used five years later. A hydraulic line hauler were introduced in the mid-1980s, and supply rate was gradually increased. Surveys on the supply and upgrading of fishing equipment utilized visiting researchers. Therefore, the relative fishing power index in the Danish seine fishery increased stably from 1.0 in 1970 to 1.0 in 1980, to 1.2 in 1990, to 1.3 in 2000 and to 1.3 in 2010. The results are expected to contribute to reasonable fisheries stock management.

• 생태와환경
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• 제42권4호
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• pp.495-501
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• 2009

The study was conducted in 2007~2008 in order to understand preference of physical microhabitat on the $1^{st}$-class endangered species, Gobiobotia naktongensis inhabiting the Gam Stream, tributary of Nakdong River. The total number of fish caught from the study sites was 3,671 representing 7 families 24 species. There were 8 Korean endemic species including Odontobutis platycephala, and 2 introduced species (Carassius cuvieri, Micropterus salmoides) were found. According to investigation and analysis of physical microhabitat on Gobiobotia naktongensis caught in the Gam Stream, a total of 57 individuals were found at shallow depth (0.14~0.46 m) and run (0.239~0.585m $sec^{-1}$). As a result of sieve analysis, stream beds consisted of about 1% gravel and 99% sand (83.4% coarse sand, 15.6% find sand). Therefore, Gobiobotia naktongensis seemed to inhabit shallow-run with coarse sand bed than deep-pool microhabitat. The findings indicate preference of physical microhabitat on Gobiobotia naktongensis, and it is important to enhance efficiency of fish conservation and ecological restoration with understanding species-specific characteristics in microhabitat including protected species.

• Animal cells and systems
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• 제16권6호
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• pp.498-505
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• 2012

This study uses the mitochondrial DNA control region to identify the genetic diversity and population structure of the marbled soles (Pleuronectes yokohamae) that inhabit Jinhae Bay and Yokji Island in the nearby sea and the adjacent waters of Namhae, Hansan Island, and Jaran Bay. Direct sequencing of the PCR products revealed 379 bp sequences with 83 variable nucleotide sites, defining a total of 91 haplotypes. The haplotype diversity was high, ranging from $0.917{\pm}0.031$ to $0.983{\pm}0.008$, and nucleotide diversity ranged from $0.015{\pm}0.008$ to $0.024{\pm}0.012$. In addition, 48 haplotypes (52.7%) were unique. Pairwise $F_{ST}$ values were very low, with the maximum value occurring between PYH (Hansan Island) and PJI (Jinhae Bay) ($F_{ST}$ = 0.011). Therefore, no significant genetic differentiation was evident between any pair of sampling localities.

• 한국환경과학회지
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• 제29권11호
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• pp.1079-1088
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• 2020

The Shinbulsan wetland, located in Yangsan-si, Gyeongsangnam-do, South Korea, was designated as a conservation area in 2004. The area was monitored from 2015 to 2019 to investigate the community characteristics and changes of benthic macroinvertebrates. Between 2015 and 2016, several insects of the orders Ephemeroptera, Odonata, and Hemiptera were identified, but their numbers decreased significantly in 2017 and 2018 following the loss and recovery of the moor owing to drought. During this period, there were relatively more insects of the order Diptera. Within this order, three functional feeding groups, gathering-collectors, plant-piercers, and predators were investigated. Predator species were the most abundant (83.3%), whereas gathering-collectors accounted for the largest proportion of individual insects (50.5%). Between 2015 and 2016, when the moors were stable, groups I and III had the highest community stability. After 2017, when the moors had dried up, group III effectively disappeared because of its lower relative resistance and resilience, and only taxa belonging to group I remained. The results of this study indicate that benthic macroinvertebrates that adapt early during moor formation inhabit the Shinbulsan wetland.

• 한국자원식물학회지
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• 제24권6호
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• pp.666-674
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• 2011

To elucidate genetic diversity of common reed in Korea, we collected a total of 674 common reed plants from 27 regions in South Korea. Hierarchical clustering using 7 morphological traits divided the 27 common reed populations into 7 groups. Random amplified polymorphic DNA (RAPD) results identified three distinct groups of common reed. Common reed accessions in group I mostly inhabit coastal areas. Group II includes reeds mostly collected from inland areas. Group III consists of common reed accessions collected from inland and coastal areas, suggesting that this group might contain hybrids. In summary, we suggest that parapatric speciation might be an important factor in the genetic diversity of common reed and geographical speciation of common reed that might be also affected by environmental gradients.

• ETRI Journal
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• 제32권4호
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• pp.512-519
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• 2010

A cooperative model is presented to enable sharing of the spectrum with secondary users. Compared with the optimal model and competitive model, the cooperative model could reach the maximum total profit for secondary users with better fairness. The cooperative model is built based on the Nash equilibrium. Then a conceding factor is introduced so that the total spectrum required from secondary users will decrease. It also results in a decrease in cost which the primary user charges to the secondary users. The optimum solution, which is the maximum total profit for the secondary users, is called the collusion state. It is possible that secondary users may leave the collusion state to pursue the maximum of individual profit. The stability of the algorithm is discussed by introducing a vindictive factor to inhabit the motive of deviation. In practice, the number of secondary users may change. Adaptive methods have been used to deal with the changing number of secondary users. Both the total profit and fairness are considered in the spectrum allocating. The shared spectrum is 11.3893 with a total profit of 65.2378 in the competitive model. In the cooperative model, the shared spectrum is 8.5856 with the total profit of 73.4963. The numerical results reveal the effectiveness of the cooperative model.

• 한국환경생태학회지
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• 제29권2호
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• pp.210-220
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• 2015

We quantified temporal and spatial changes in the habitat for fish populations, the distribution of mandarin fish(Siniperca scherzeri) and an introduced species, largemouth bass(Micropterus salmoides) in Lake Paro and inflowing streams. The number of fish species identified in Lake Paro and the tributary streams included 10 families, 24 species and 10 families 30 species, respectively. The dominant fish species in Lake Paro were Zacco platypus, Hemibarbus labeo, Squalidus gracilis majimae, S. scherzeri and Tridentiger brevispinis, Z. platypus, Z. koreanus, and S. gracilis majimae in the inflowing streams. Although the habitat segregation for S. scherzeri and M. salmoides occurs, these two species showed the use of the fishes of the family Gobiidae as an important prey item based on IRI analysis. S. scherzeri and M. salmoides preyed mainly on T. brevispinis(67.4 %) and R. brunneus(84.0 %), respectively. The species preyed on by S. scherzeri and M. salmoides were benthic fishes that inhabit shallow water depths around the lake and have little swimming ability.