• Ocean and Polar Research
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• v.28 no.1
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• pp.13-23
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• 2006

This study was conducted to investigate the community structure and distributional pattern of meiobenthos on the sediment of the mangrove forest and seagrass bed in the Chuuk lagoon. The samples were collected by an acryl corer at 14 stations. Nematodes were the most abundant meiobenthos, followed by ciliophorans and polychaetes; these taxa comprised more than 70% of the total abundance at all stations. The meiofuuna sampled in seagrass bed were more diverse than those of mangrove substrates. Total densities were higher in mangrove stations than other sites, averaging 1,671 to $2,967inds/10cm^2$. Densities in seagrass area ranged between 605 and $1,053inds/10cm^2$. Biomasses, however, were higher in seagrass bed $(975-2,167{\mu}g\;free\;dry\;weight/10cm^2)$ than in mangrove area $(1,064-1,180{\mu}g\;free\;dry\;weight/10cm^2)$. Ordination chart by MDS of major meiofaunal density in each station showed difference between mangrove area and seagrass area in terms of habitat of meiobenthos.

• Ocean and Polar Research
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• v.24 no.4
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• pp.419-427
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• 2002

Meiobenthic community structure near Dokdo was investigated during two survey periods of June, 1999 and October 2000. Meiobenthos were separated from the sediment core samples collected from eight stations. A total of 19 meiobenthic animal groups were identified from those core samples. The most abundant meiobenthic animals belonged to Phylum Nematoda in both seasons and all stations. Sarcomastigophorans, nauplius of crustaceans, and benthic harpactiocoids were the next abundant meiobenthos. Vertical distribution of meiobenthic animals showed the highest individual numbers in the surface sediment layers of 0-1cm depth with a steep decreasing trend with depth for the three sampling stations (A0, A9', A19) located in the continental slope. Horizontal distribution of meiobenthic animals for the study area near Dokdo showed lower density at the sampling stations near Dokdo and the lowest density of meiobenthos in A19 (depth-2261 m). For size distribution, analysis showed that animals which fit onto the mesh size of 0.125mm were abundant. This study suggested that the continental shelf near Dokdo have a more unstable environment fo meiobenthos than the continental slope.

• Ocean and Polar Research
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• v.33 no.3
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• pp.193-209
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• 2011

The community structure of meiobenthos was studied at 16 stations within sandy tidal and subtidal zones in Jangbongdo in the Yellow Sea, Korea from Aug. 2006 to Jan. 2007. Meiobenthic organisms were collected by three core samples, with a 3.6 cm diameter, from each sediment sample taken with a Smith-McIntyre Grab. Mean grain size of study stations ranged from $1.49{\phi}$ to $3.55{\phi}$. Composition of sand ranged from 80.38% to 99.89%. There was reduction in total abundance and biomass of meiobenthos from summer to winter. Total densities of meiofauna ranged between 17 inds./10 $cm^2$ and 853 inds./10 $cm^2$. Nematodes, gastrotricha, nauplius and harpacticoids appeared as major taxa in decreasing order. This study shows that major taxa comprised 90 percent of total abundance. Most meiofaunal organisms are concentrated in the upper sediment layers and the total abundance and biomass of organisms in the tidal zone is higher than the subtidal zone.

• Animal Systematics, Evolution and Diversity
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• v.21 no.1
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• pp.57-66
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• 2005

Tenuidraconema philippinensis, a new species of free-living marine nematode, collected from the shallow subtidal coarse sediments of the Philippines, is described. The new species differs from T. fiersi Decraemer, 1989 and T. koreensis Rho and Kim, 2004, by the following characteristics: the position of 12 cephalic adhesion tubes in both sexes (all 12 cephalic adhesion tubes inserted on the body annules), the number of posterior sublateral adhesion tubes (12 in male and 11 in female) and posterior subventral adhesion tubes (16 in male and 17 in female), and the absence of the intermingled somatic setae in male. This is the first discovery of the genus Tenuidraconema in the Philippines.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.39 no.spc1
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• pp.203-213
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• 2006

The spatial patterns of meiobenthic communities in deep-sea sediment were examined. Sediment samples for analyzing of meiobenthic community structure were collected using a remote operated vehicle (ROV), multiple corer TV grab at 20 stations at five sites. In all, 15 meiofauna groups were recorded. Nematodes were the most abundant taxon. Benthic foraminiferans, harpacticoid copepods, polychaetes, and crustacean naupii were also dominant groups at all sites. The total meiofauna density at the study sites varied from 49 to 419 ind./$10cm^2$. The maximum density was recorded at a site located in Challenger Deep in the Mariana trench where simple benthic foraminifera with organic walls flourish. These distinctive taxa seem to be characteristic of the deepest ocean depths. Active hydrothermal sediments contain up to 150 harpacticoid copepods per $10cm^2$ of sediment. In a inactive ridge sediments, devoid of macrofaunal organisms:, the abundance of harpacticoid copepods never exceeded 15 ind./$10cm^2$. Multivariate analysis (multidimensional scaling) revealed significant differences in community structure among the three regions; near an active hydrothermal vent, in the deepest ocean depths and at typical deep-sea bed sites.

• Parasites, Hosts and Diseases
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• v.61 no.3
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• pp.240-250
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• 2023

The genus Anisakis is among the most significant parasites to public health, as it causes anisakiasis, a parasitic infection in humans resulting from consuming raw or undercooked seafood. Although the infection status of Anisakis in second intermediate hosts, such as marine fishes and cephalopods, and humans have been severally reported in Korea, no information about the definitive host in Korean waters is available. In 2014, 2 adult gastric nematodes were collected from a common minke whale (Balaenoptera acutorostrata) found in the East Sea, Korea. These worms were identified as A. simplex sensu stricto (s.s.) by comparing the mitochondrial COX2 marker with previously deposited sequences. Phylogenetic and phylogeographic analyses of A. simplex (s.s.) worldwide revealed 2 distinct populations: the Pacific population and the European waters population. This is the first report on adult Anisakis and its definitive host species in Korea. Further studies on Anisakis infection in other cetacean species and marine mammals in Korean seas are warranted.

• Journal of Environmental Science International
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• v.29 no.11
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• pp.1125-1139
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• 2020

This study investigated the distributional pattern of meiobenthos associated with future deep-sea mining in the Korea Deep Ocean Study area present in the Clarion-Clipperton Fracture Zone (CCFZ) located in the southeastern part of the North Pacific Ocean. Standing stocks of meiobenthos were investigated in benthic impact experiment sites (BIS) and Korea Institute of Ocean Science & Technology long-term monitoring (KOMO) sites during the 2008-2014 annual field survey. A total of 14 taxa of meiobenthos were identified. Nematodes were the most abundant taxon (60-86%). Harpacticoid copepods (5-26%) and benthic foraminifera (1-12%) were also dominant at all sites. The total meiobenthic densities varied from 4 to 150 ind./10 cm2. The mean value of total meiobenthic abundance was higher at BIS than at KOMO sites, but there was no significant difference between the two sites. The mean values of the number of taxa and biomass at BIS and KOMO sites were similar. The mean abundance of nematodes that were the most dominant taxa was also higher at BIS than at KOMO sites. The standing stocks in our study sites were relatively lower than those previously reported at other CCFZ sites. These results seem to reflect a low organic concentration in the study area.

• Korean Journal of Environmental Biology
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• v.33 no.2
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• pp.170-176
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• 2015

Oncholaimid nematode, Oncholaimus secundicollis Shimada, Kajihara and Mawatari, 2009, is firstly reported based on a comparative morphological study. The present specimens of O. secundicollis are collected from rocky intertidal seagrass on the eastern coast of Korea. Oncholaimus secundicollis is distinguished from all of its congeners by the following combination of morphological characteristics: buccal cavity large with thick cuticular wall and three teeth, left subventral tooth larger than right subventral or dorsal teeth, and the presence of two remarkable precloacal papillae with nine pairs of cloacal setae and single ventral tail papilla with two pairs of short setae. In this study, we provide taxonomic description and illustration of unrecorded species of the genus Oncholaimus.

• Korean Journal of Environmental Biology
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• v.40 no.2
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• pp.125-137
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• 2022

To assess the characteristics of meiofaunal community fluctuations related to environmental factors, seasonal surveys were conducted in the subtidal zone of Hallyeohaesang National Park. The average depth of the study area was about 20 m, and the average water temperature at the bottom was low in winter(11.33℃) and high in summer(17.95℃). The sedimentary particles mainly comprised silt and clay at most stations. The abundance of meiofauna ranged from 81.7 to 1,296.5 Inds. 10 cm^-2, and the average abundance was 589.3 Inds. 10 cm^-2. The average abundance of meiofauna in each season was the lowest at 416.5 Inds. 10cm^-2 in winter and the highest at 704.5Inds.10 cm^-2 in spring. The dominant taxa were nematodes (about 92%) and harpacticoids (about 5%). In the cluster analysis of meiofaunal communities, they were divided into four significant groups. The largest group mainly contained spring and summer samples, and contained stations with a high nematode density of over 500 Inds. 10 cm^-2 and harpacticoids below 50 Inds. 10 cm^-2 with a high composition ratio of nematodes. In the cluster analysis, no regional division was found between the stations, and it was thought to be divided by the seasons with high abundance according to seasonal variation and the composition ratio of nematodes and harpacticoids. In the Spearman rank correlation analysis, the density of total meiofauna and the most dominant taxa, nematodes, was not significantly related to environmental factors. However, the density of harpacticoids had a significant positive correlation with water depth and a negative correlation with sediment particle size.

• Ocean and Polar Research
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• v.27 no.3
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• pp.299-309
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• 2005

The community structure of meiobenthos was studied in the sediment of Kongfjorden, Spitsbergen of Svalbard Island in the Arctic Sea. Samples of meiobenthos were collected in August, 2003. Meiobenthic organisms were collected by SCUBA and van veen grab or acryl sub-corers 34mm in internal diameter, and were taken from upper sediment to a depth of 3cm at each station. A total of 26 meiofaunal groups were found in the sediment of Spitsbergen in Svalbard Island. Nematodes were the most dominant faunal group. Sarcomastigophorans, benthic harpacticoids, and nauplius larvae of crustaceans, were also important components of the meiobenthic community of Kongsfjorden. All of these low faunal groups were comprised of more than 90% of total meiobenthos at every station. The total density of meiobenthos at each station was highest at station MeG 6 $(3,583{\pm}1,137inds./10cm^2)$, and lowest at station $MeG9(28{\pm}1inds./10cm^2)$. Meiobenthos in general showed the highest density in the upper 1cm layer. This may be associated with food and oxygen supply to subsurface. Harpacticoids showed extreme preference at the surface and little presence in layers deeper than 2cm. These animals may be less resistant to oxygen deficiency, and nauplius also showed the same trend. However, in St. MeG 8 and 9, meiobenthos were dense at depths of more than 0-1cm, at especially at depths of 2-3m because of relatively easy penetration of oxygen. Based on the results of cluster analysis, three meiobenthos assemblages were distinguished: one was in the outer and two were in the inner fjord. Station SCU 5 was grouped with the meiobenthos assemblage located in the outer fjord. The outer ford community was characterised by : 1) a relatively low mean number of meiobenthos taxa, 2) a relatively high density of harpacticods and nauplius. One of the inner ford communities (a group of four nation: MeG 2, 3, 8, 9) was in the proximity of the glaciers. Specifically, it was characterised by : 1) a low mean number of meiobenthos taxa, 2) a low density. The other inner ford community was characterised by both a high density and great mean number of meiofaunal taxa.