• ALGAE
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• v.38 no.2
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• pp.111-126
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• 2023

Mixotrophic dinoflagellates act as primary producers, prey, and predators in marine planktonic food webs, whereas exclusively autotrophic dinoflagellates are primary producers and prey. Species of the dinoflagellate genus Scrippsiella are commonly found in marine ecosystems and sometimes cause harmful red tides. Among the 28 formally described Scrippsiella species, S. acuminata has been found to be mixotrophic and two unidentified species have been found to be mixotrophic. To determine whether the other species in this genus are similarly mixotrophic, the mixotrophic ability of S. donghaiensis SDGJ1703, S. lachrymosa SLBS1703, S. masanensis SSMS0908, S. plana SSSH1009A, and S. ramonii VGO1053 was explored using 15 potential prey items, including 2-㎛ fluorescently labeled microspheres (FLM) and heterotrophic bacteria (FLB), the cyanobacterium Synechococcus sp., and various microalgal prey species. The ability of S. acuminata to feed on FLM and FLB was also investigated. We found that S. donghaiensis, S. lachrymosa, S. masanensis, S. plana, and S. ramonii did not feed on any potential prey tested in this study, indicating a lack of mixotrophy. However, S. acuminata fed on both FLM and FLB, confirming its mixotrophic ability. These results lowered the proportion of mixotrophic species relative to the total number of tested Scrippsiella species for mixotrophy from 100% to 29-38%. Owing to its mixotrophic ability, S. acuminata occupies an ecological niche that is distinct from that of S. donghaiensis, S. lachrymosa, S. masanensis, S. plana, and S. ramonii.

• Parasites, Hosts and Diseases
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• v.53 no.1
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• pp.135-139
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• 2015

A total of 1,708 small mammals (1,617 rodents and 91 soricomorphs), including Apodemus agrarius (n = 1,400), Microtus fortis (167), Crocidura lasiura (91), Mus musculus (32), Myodes (= Eothenomys) regulus (9), Micromys minutus (6), and Tscherskia (= Cricetulus) triton (3), were live-trapped at US/Republic of Korea (ROK) military training sites near the demilitarized zone (DMZ) of Paju, Pocheon, and Yeoncheon, Gyeonggi Province from December 2004 to December 2009. Small mammals were examined for their intestinal nematodes by necropsy. A total of 1,617 rodents (100%) and 91 (100%) soricomorphs were infected with at least 1 nematode species, including Nippostrongylus brasiliensis, Heligmosomoides polygyrus, Syphacia obvelata, Heterakis spumosa, Protospirura muris, Capillaria spp., Trichuris muris, Rictularia affinis, and an unidentified species. N. brasiliensis was the most common species infecting small mammals (1,060; 62.1%) followed by H. polygyrus (617; 36.1%), S. obvelata (370; 21.7%), H. spumosa (314; 18.4%), P. muris (123; 7.2%), and Capillaria spp. (59; 3.5%). Low infection rates (0.1-0.8%) were observed for T. muris, R. affinis, and an unidentified species. The number of recovered worms was highest for N. brasiliensis (21,623 worms; mean 20.4 worms/infected specimen) followed by S. obvelata (9,235; 25.0 worms), H. polygyrus (4,122; 6.7 worms), and H. spumosa (1,160; 3.7 worms). A. agrarius demonstrated the highest prevalence for N. brasiliensis (70.9%), followed by M. minutus (50.0%), T. triton (33.3%), M. fortis (28.1%), M. musculus (15.6%), C. lasiura (13.2%), and M. regulus (0%). This is the first report of nematode infections in small mammals captured near the DMZ in ROK.

• Korean Journal of Environmental Biology
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• v.33 no.2
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• pp.230-239
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• 2015

Monthly variations of cirriped larvae near Oryuk islets off Busan were investigated at four stations from January 2012 to January 2013. Zooplankton was vertically collected, using NORPAC net (mouth 45 cm, mesh $200{\mu}m$), from the surface to 1 m above the bottom. 12 species belong to five genera of 4 families were identified including one unidentified species. Cirriped larvae occupied small portion of total zooplankton, ranging 0.02 to 4.1% of total zooplankton densities. The densities varied monthly from $1inds.m^{-3}$ to $715.1inds.m^{-3}$, which was highest in September and lowest in February. Chthamalus challengeri, Balanus glanula, B. improbisus, B. nubilus and Octomeris sulcata were dominant species and accounted for 70.1% of total cirriped larvae. Larval densities of cirripeds between stations were not significantly different (F=0.237, p=0.870). The larval communities were grouped into two groups by cluster analysis. We discussed the distribution patterns of cirriped larvae in relation to oceanographic characteristics in the study area.

• ALGAE
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• v.19 no.1
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• pp.15-22
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• 2004

This study investigated the temporal and spatial dynamics of an epilithic algal community in the Hantan River in November 2001, February, May and August 2002. It was identified a total of an epiphlithic 301 taxa which were composed of 275 species, 16 varieties and 10 unidentified species. The standing crops ranged between 598,600-16,525,200 cells $\cdot$ $cm^2$ and showed the temporal and spatial variations, A higher value was found at the lower station than the upper station in winter, but a higher value was found at the upper station than the lower station in summer due to the effects of typhoons. Chlorophyll concentrations ranged between 13.4-304.2 ${\mu}g$ $\cdot$ $cm^2$. Standing crops and chlorophyll showed similar trends in autumn and winter, but temporal dynamics were not apparent in the overgrowth of Lyngbya, Schizothrix and so others in Cyanophyceae in spring and summer. They were composed of species in Chlorophyceae-Bascillariophyceae-Cyanophyceae and no seasonal effect was detected. Low diversity index values probably indicated the effects of environmental stresses (water temperature, flow and current velocity) other than organic pollution. An assessment of organic pollution using epilithic diatoms (DAIpo) showed $\alpha$-oligosaprobic states at the upper- and mid- stations, and $\alpha$-mesosaprobic states at the lower- stations.

• Korean Journal of Microbiology
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• v.29 no.5
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• pp.319-328
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• 1991

this study was performed for the purpose of surveying the distribution and characteristics of the Vibrio species in the diseased farm flounders (Paralichthys olivaceus) during the winter season in Korea. Samples were collected along the southern coast in the Sinam, Keoje Island, and Teosu areas from November '90 to Feburary '91. Nine species of Vibrio were identified as V. tubiashii (85 strains), V. damsela (78 strains), V. anguillarum (21 strains), V. compbelli (9 strains), V. fluvialis (9 strain), V. costicola (1 strain), V. alginolyticus (1 strain), V. gazogenes (1 strain), V. marinus (1 strain), and unidentified 3 groups of bacteria (154 strains) which may have related with V. tubiashii were isolated. Eleven kinds of discs (BBL Co.) were used for antibiotic susceptibility test and 116 strains were selected for the experiment. Most bacteria were powerfully inhibited their growth by 4 antibiotics such as cephalothin, chloramphenicol, colistin, and tetracycline, but they were poorly inhibited by 4 antibiotics such as carbenicillin, kanamycin, penicillin G, and streptomycin.

• Korean journal of applied entomology
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• v.33 no.4
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• pp.237-241
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• 1994

Surveys were conducted in 66 ginseng fields damaged by insect and other an~mal pests from 1984 to 1993. Holohichio rnoroso, Holotrichio dromphalio, Holotrichia titonis Malodera orientaliq Ectinus sericeus, Gyllotalpa ofricana, Teleog~iluse mmo, Ostrinio furnacoii* Agrotis tokionis, Marnestro brassicae, Hydrellia griseolo, unidentified stem maggo$, Pseudococcus comstocki (13 species of insects). Deroceras uarions (slug), Acusta despecta sieboldiona (snail), probably two species of rats. and pheasant species were ascertained to damage ginseng plants M them, Holotrich~a morosa, Holotrichia diomphalia, Gryliotaipo africanq Deroceras uarions, Acusto despech siebaldiano showed higher frequencies. Underground (root) damage occul~ed mainly in spring penod (MayJune) and fall period (September-Odober) in 2-year-old glnseng fields at slopes, and aboveground (leaf and stem) damage occurred mainly in spring period in 3 or more-year-old ginseng iields mulched with rice straws at plains. Three ginseng fields were abolished due to heavy underground damage.

• Journal of Forest and Environmental Science
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• v.30 no.3
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• pp.277-284
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• 2014

Status of Arbuscular Mycorrhizal (AM) colonization in seven tree species (Albizia saman, Acacia auriculiformis A. Cunn. ex Benth., Albizia lebbeck, Chickrassia tabularis A. Juss., Eucalyptus camaldulensis Dehnn., Gmelina arborea (Roxb) DC, Swietenia macrophylla King.) collected from the hilly areas of Chittagong University (CU) was investigated. Roots and rhizosphere soil samples were collected in different seasons (pre-monsoon, monsoon and post monsoon). Percentage of AM colonization in root and number of spores/100 gm dry soil were assessed. The result of the investigation reveals that the intensity and percentage of AM colonization varied in different forest tree species in different seasons. In this study, maximum AM colonization and spore population were found in pre-monsoon and minimum were in monsoon season. The intensity of colonization was maximum in C. tabularis (74.43%) in pre-monsoon, A. lebbeck (69.45%) in monsoon and S. macrophylla (67.8%) in post monsoon seasons and minimum in A. auriculiformis (53.75%) during pre-monsoon, A. saman (24.4%) in monsoon and A. saman (19.36%) in post monsoon. The number of spores found per 100 g dry soil ranged between 164-376 during pre-monsoon, 27-310 during monsoon and 194-299 in post monsoon season. Out of six recognized genera of AM fungi, Glomus, Sclerocystis, Entrophospora, Scutellospora, Acaulospora and other unidentified spores were observed.

• Korean Journal of Environmental Biology
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• v.30 no.2
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• pp.151-155
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• 2012

Korean freshwater turtles are divided into native turtles, Chinemys reevesii in Geoemydidae, Pelodiscus sinensis in Trionychidae, and imported turtles, Trachemys scripta elegans, T. s. scripta, Pseudemys rubriventris and Ocadia sinensis. In this study, we determined the distribution of Korean freshwater turtles based on a field study and literature study, and considered the taxonomic position of unidentified native turtles. The study was carried out between May 2010 and November 2011 during the day time, and the capturing tool used to collect turtles consisted of net and metal frame. C. reevesii and P. sinensis were found in 16 and 11 places, respectively. C. reevesii, which inhabits the Korean peninsula, is a taxonomically controversial species, but it is presumed that the turtle belongs to Mauremys. Moreover recent taxonomic studies of the soft-shell turtle have shown that the Korean native species is P. maackii, and P. sinensis was imported from abroad and has been in the natural habitats of Korea since 1970s. The exterior shape and skeletal form of P. maackii and P. sinensis are nearly similar. However, the skin color and yellow spots on the shell could be used to distinguish the two species.

• Parasites, Hosts and Diseases
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• v.56 no.3
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• pp.301-304
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• 2018

Rodents are important reservoirs of diseases affecting people and livestock, and are major sources of parasite contamination of agricultural products. We surveyed the infection status of intestinal helminths in 2 species of field mice, Apodemus agrarius and A. peninsulae, captured in the agricultural fields of Gangwon-do and Chungcheongnam-do, Korea. Total 83 mice (57 A. agrarius and 26 A. peninsulae) were collected in 2 surveyed areas, and the intestines of each mouse were opened with scissors, and then intestinal contents were examined with microscope. Total 6 species of intestinal helminth were detected in 61 (73.5%) out of 83 mice examined. Four species of nematode, i.e., Nippostrongylus brasiliensis, Aspiculuris tetraptera, Heterakis spp. and ascarid, were found in 40 (48.2%), 14 (16.9%), 11 (13.3%) and 13 (15.7%) mice respectively. One species of cestode, Hymenolepis diminuta and 1 unidentified egg were also detected in the intestines of 14 (16.9%) and 1 (1.2%) mice, respectively. Conclusively, this study identified 5 helminth species in the gastrointestinal tracts of wild rodents captured in some areas in central and northern Korea, and N. brasiliensis was the most prevalent (dominant) species rather than zoonotic ones.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.58 no.4
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• pp.326-333
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• 2022

To provide information needed for managing fish resources and protecting the ecosystem of Cheonsu Bay, bimonthly variations in species composition and abundance of fish eggs and larvae were investigated. The samples were collected by using bongo net at three different stations from February 2020 to December 2021. Fish eggs were divided into Engrualis japonicas and unidentified eggs, of which Engragulis japonicus accounted for 85.6% of the total eggs collected. A total of 21 species representing 17 families and 6 orders were collected. The three dominant species were Gobiidae spp, Thryssa hamiltonii and E. japonicus and these three species accounted for 74.1% in the total number of individuals. The number of species was highest in August, 2020 and lowest in February, 2020 and 2021; the number of individuals was highest in August, 2020 and lowest in February, 2020. Temporal changes in the abundances of pelagic eggs and larval fishes corresponded with temperature.