• Journal of Species Research
• /
• v.6 no.spc
• /
• pp.26-37
• /
• 2017

Rotifers collected from various terrestrial and aquatic habitats such as mosses on trees or rocks, tree barks, wet mosses and wet leaf litter at streams, and dry leaf litter at four different locations in Korea, were investigated. Thirteen species belonging to nine genera in five families of monogonont and bdelloid rotifers were identified: Bryceella perpusilla Wilts, Martinez Arbizu and Ahlrichs, 2010, Collotheca ornata (Ehrenberg, 1830), Habrotrocha flava Bryce, 1915, H. pusilla (Bryce, 1893), Macrotrachela aculeata Milne, 1886, M. plicata (Bryce, 1892), Mniobia montium Murray, 1911, M. tentans Donner, 1949, Notommata cyrtopus Gosse, 1886, Philodina lepta Wulfert, 1951, P. tranquilla Wulfert, 1942, Pleuretra hystrix $Barto{\check{s}}$, 1950 and Proalinopsis caudatus (Collins, 1873). All these rotifers are new to Korea, and B. perpusilla, H. flava, M. montium, P. caudatus, P. hystrix and P. lepta are new to Asia as well. Of interest, the present study is the first to record B. perpusilla outside its type locality. In addition, P. lepta has previously been recorded from only three European countries.

• Journal of Species Research
• /
• v.10 no.4
• /
• pp.356-363
• /
• 2021

Heterotrophic nanoflagellates (HNFs, 2-20 ㎛ in size) are substantially capable of controlling bacterial abundance in aquatic environments, and microbial taxonomists have studied ecologically important and abundant HNFs for a long time. However, the classifications of HNFs have rarely been reported in Korea on the basis of morphology and 18S rDNA sequencing. Here, previously reported five HNFs from non-Korean habitats were isolated from Korean coastal seawater or intertidal sediments for the first time. Light microscopic observations and 18S rDNA phylogenetic trees revealed that the five isolated species were Cafeteria burkhardae strain PH003, Cafeteria graefeae strain UL001, Aplanochytrium minuta (formerly Labyrinthuloides minuta) strain PH004, Neobodo curvifilus strain KM017 (formerly Procryptobia sorokini), and Ancyromonas micra (formerly Planomonas micra) strain IG005. Being morphologically and phylogenetically indistinct from its closest species, all isolates from Korea were therefore regarded as identical species detected in other countries. Thus, this result indicates an expansion of known habitats that range from those of the five isolates in natural ecosystems on Earth.

• Applied Chemistry for Engineering
• /
• v.33 no.4
• /
• pp.352-366
• /
• 2022

Nuclear power plant operations for electricity generation, rare-earth mining, nuclear medical research, and nuclear weapons reprocessing considerably increase radioactive waste, necessitating massive efforts to eradicate radioactive waste from aquatic environments. Cobalt (⁵⁸Co) and strontium (⁹⁰Sr) radioactive elements have been extensively employed in energy generation, nuclear weapon testing, and the manufacture of healthcare products. The erroneous discharge of these elements as pollutants into the aquatic system, radiation emissions, and long-term disposal is extremely detrimental to humans and aquatic biota. Numerous methods for treating radioactive waste-contaminated water have emerged, among which the adsorption process has been promoted for its efficacy in eliminating radioactive waste from aquatic habitats. The current review discusses the adsorptive removal of radioactive waste from aqueous solutions using low-cost adsorbents, such as graphene oxide, metal-organic frameworks, and inorganic metal oxides, as well as their composites. The chemical modification of adsorbents to increase their removal efficiency is also discussed. Finally, the current state of ⁵⁸Co and ⁹⁰Sr removal performances is summarized and the efficiencies of various adsorbents are compared.

• Journal of Environmental Science International
• /
• v.26 no.12
• /
• pp.1341-1353
• /
• 2017

This study aimed to identify the aquatic and riparian factors associated with the presence/absence of the Eurasian otter in the Nakdong river basin, where the species is relatively more abundant than other otter species. Environmental factors and presence records were collected. Geographical Information System technology and chi-square test were used to compare environmental gradients in aquatic and riparian factors between presence and absence sites. Aquatic habitat attributes were evaluated with natural riverside sandbars and channel crossing artificial structures, the ratio of channel width to alluvial plain width, riverbed substrate, and flow diversity. Riverbank characteristics, bank materials, man-made embankment types, and land use/land cover of inland and riverside areas were selected as riparian habitat attributes. Compared to the aquatic attributes, riparian attributes were highly significant when assessing otter presence and absence sites, suggesting that conservation of suitable riparian areas to provide maternity and resting areas for otter species is essential in the Nakdong river basin. None of the aquatic attributes examined were statistically significant when evaluating otter presence or absence. These results indicate that the presence of suitable riparian area for resting and reproduction habitats is more critical to the presence of Eurasian otter than food availability in aquatic areas. To inform implementation of effective conservation actions, broad-scale factors, such as watershed attributes, would be needed to further assess habitat conditions of the Eurasian otter.

• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.33 no.6
• /
• pp.501-507
• /
• 2000

Distribution and habitat characteristics of Zostera (Zosteraceae) in the eastern coast of Korea were examined along with plant monohology, sediment composition and physicochemical factors of seawater from June 1998 to July 2000, The results showed that three species, Zostera marina, Z. asiatica and Z, caespitosa were found in specific habitats. The depth of habitat for Z. asiatica was deeper ($8.5{\~}15.0 m$) than that of Z. marina ($1.3{\~}5.6 m$) and Z. caespitosa ($3.2{\~}5.2 m$). Z. marina beds were observed at brackish-water, port and inner bay with the sediment type of sand or muddy sand. Habitats of Z. asiatica were restricted to the open bay with the sediment type of sand, Zostera have been described with regard to different growth forms of vegetation, flowering shoot and life history. Vegetation and flowering shoot length varied significantly with habitats; values ranged $66.8{\~}110.0 cm$ and $128.0{\~}217,8 cm$, respectively. Morphology of Z. marina varied with water depth and different substrates. Morphological characteristics of Z. asiatica showed a new phenotype at the deeper water depth. Vegetation and flowering shoots of Z. caespitosa were not significantly different between study sites (values ranged from 64.9 cm to 70.3 cm). Nutrient concentrations of seawater were higher at southern part than at middle part of the eastern coast of Korea. Distribution of Zostera in the eastern coast of Korea was dependent upon differences in water depth and habitat environments, by which affected the morphological differences were affected.

• Fisheries and Aquatic Sciences
• /
• v.27 no.3
• /
• pp.145-158
• /
• 2024

Life history characteristics, habitat landscape, and historical events are believed to have shaped the patterns of genetic variation in many taxa. The bony lip barb, Osteohilus vittatus, represent a potamodromous fish that complete all life cycle in freshwater and is widely distributed in Southeast Asia. It usually lives in small rivers and other freshwater habitats, and movement between habitats for either food or reproduction has been typical. These life history characteristics may promote gene flow, leading to less structured populations. However, many freshwater habitats are fragmented, which restricts gene flow. We investigate how this interplay has shaped patterns of genetic variation and phylogeographic structure within this species in the Sundaland, a biodiversity hotspot with a complex geological history, using mitochondrial cytochrome oxidase I (mtCOI) as a genetic marker. Forty-six mtCOI sequences of 506 bp long were collected from ten localities, eight geographically isolated and two connected. The sequences were used for population genetic and phylogeographic analyses. Our results showed a low genetic diversity within populations but high between populations. There was a deep phylogeographic structure among geographically isolated populations but a lack of such structure in the connected habitats. Among geographically isolated populations, sequence divergence was revealed, ranging from 1.8% between Java and Sumatra populations to 12.2% between Malaysia and Vietnam. An indication of structuring was also observed among localities that are geographically closer but without connectivity. We conclude that despite high dispersal capacity, the joint effects of historical events, long-term geographic isolation associated with sea level oscillation during the Pleistocene, and restricted gene flow related to lack of habitat connectivity have shaped the phylogeographic structure within the O. vittatus over the Sundaland.

• Korean Journal of Plant Taxonomy
• /
• v.43 no.1
• /
• pp.34-45
• /
• 2013

The Polygonum amphibium complex (Poygonaceae) is a highly polymorphic taxon that can grow in aquatic environments as well as in moist terrestrial habitats. Aquatic and terrestrial plants of the P. amphibium complex vary significantly in morphology and exhibit very complicated patterns of morphological variation, resulting in the description of numerous infra-specific taxa. Principal components analysis of 107 individuals of the P. amphibium complex from Asia and North America using 11 morphological characters showed that the aquatic plants can be discerned from the terrestrial plants by leaf size, shape, and petiole length. In contrast, both aquatic and terrestrial plants collected from the same population or locality shared identical sequences in the matK, psbA-trnH IGS, rbcL-accD IGS and trnL-trnF regions of the chloroplast DNA (cpDNA), suggesting that aquatic and terrestrial forms of the P. amphibium complex are not genetically diverged; morphological differences between the two forms are probably due to the differences in environmental conditions of the habitats. In addition, results from the morphological analysis and the maximum parsimony analysis of the cpDNA data set revealed that the plants from Asia including Korea, Japan, China, Mongolia and Russia Far East are diverged from those in North America and Europe, suggesting that the Asian populations should be recognized as a distinct variety, P. amphibium var. amurense Korsh.

• Animal Systematics, Evolution and Diversity
• /
• v.37 no.4
• /
• pp.280-286
• /
• 2021

During a field survey on Korean coastal marine waters, two ciliates belonging to the genera Pseudovorticella Foissner & Schiffmann, 1975 and Frontonia Ehrenberg, 1838 in the class Oligohymenophorea de Puytorac et al., 1974, were collected. Even though the two genera are very common in the aquatic ecosystems, they had been superficially studied in Korean habitats. Using the observation of living cells and specimens impregnated by protargol, silver carbonate, and silver nitrate, two newly recorded ciliate are identified as P. paramarina Sun, Ji, Warren & Song, 2009 and F. ocularis Bullington, 1939. A brief diagnosis, remark, and comprehensive micrographs are provided for each species.

• Fisheries and Aquatic Sciences
• /
• v.19 no.9
• /
• pp.38.1-38.5
• /
• 2016

We found specimens of foliose Bangiales from the subtidal zone of Udo, Jeju Island, Korea. In molecular analyses of rbcL sequences, these Korean specimens were almost identical to Miuraea migitae from Osaka, Japan. In the morphological comparison, Korean specimens were consistent with habitat, color, and vegetative characteristics with the description of M. migitae. This is the first record of M. migitae outside the type locality and Nagasaki in Japan. This study confirms that new or unrecorded species of the order Bangiales may be discovered from subtidal habitats.

• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.4 no.2
• /
• pp.66-74
• /
• 1971

The general morphological characteristics of scales on the body surface in Cyprininae fishes can be summarized as follows: 1) The lentic and lotic habitats have no relation to the phase of scales. 2) The scales in the anterior body parts have transverse diameters longer than their longi-tudinal diameters: in the posterior body parts, the opposite holds true. 3) The scales having the largest diameters, both longitudinal and transverse, are the lateral line scales. 4) The position of the focus on each scale move posteriorly as the scale grows. In other words, the forward growth of the scales exceeds the backward. 5) The number of ridges in each scale is in proportion to longitudinal diameter. 6) In Cyprinus, the scales on the middle part of the body surface have more grooves than those on the other parts. All scales on this species commonly show incompleted grooves on the anterior and posterior areas, but the lateral area lacks grooves entirely. 7) In Carassius, there are more completed grooves than incompleted grooves. All grooves are arranged in radial patterns on the scales.