• Korean Journal of Ichthyology
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• v.32 no.2
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• pp.110-114
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• 2020

A single specimen (40.5 mm in SL) of Clariger chionomaculatus was collected at 4 m depth on mud bottom from off Geojedo Island, Korea. This species is characterized by having an elongated body without scales, several barbels below eyes, I, 12~15 second dorsal fin rays, I, 12~14 anal fin rays; 19~20 pectoral fin rays with one free soft ray on upper part, and a unique color pattern with numerous white blotches on dorsal part of body. Because it has been known from Japan only to date, we describe in detail C. chionomaculatus as the first record from Korea. A new Korean name, "Huin-jeom-wae-mang-dug", is proposed for the species.

• Animal cells and systems
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• v.13 no.3
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• pp.339-344
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• 2009

This study aims to find out the effect of heavy metals, as is the case of EDCs (endocrine disrupting chemicals), on reproductive endocrine disruption of aquatic animals. In the present experiment zinc, which is a heavy metal well known for its androgenous activity, was used. The experimental period was 24 weeks, starting in November during the inactive stage of the clam's reproductive cycle. The experimental groups were composed of one control condition and three zinc exposure conditions (0.64, 1.07, and 1.79 mg/L). The sex ratio (F:M) was 1:1.06 in the control group and 1:1.70 in all the exposed group, illustrating the tendency for higher proportion of males with increases in zinc concentration. Gonad maturity was higher in 1.07, and 1.79 mg/L groups compared to the control group, with higher maturity observed in males than females. Intersex individuals made up 24.7% of the exposed group, while females exhibited a higher ratio than the males with increasing zinc concentration. The results of this study indicate that zinc functions as an androgenic effector on the reproduction of Gomphina veneriformis.

• Animal cells and systems
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• v.13 no.3
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• pp.351-356
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• 2009

Ciliates are undoubtedly one of the most diverse protozoans that play a significant role in ecology. However, molecular examination, based on comparing the DNA sequences, has been done on a limited number of the species. Because most ciliates are uncultivable and their population sizes are often too small, it is usually difficult to obtain sufficient genomic DNA required for PCR based experiments. In the present study, we evaluated the effectiveness of four commercial DNA extraction procedures that extract high quality genomic DNA from a single ciliate cell. It was discovered that RED Extract-N-$Amp^{TM}$ PCR kit is the best method for removing PCR-inhibiting substances and minimizing DNA loss during purification. This method can also amplify more than 25 reactions of PCR. In addition, this technique was applied to single cells of 19 species belonged to 7 orders under 5 classes that isolated from mixed natural populations. Their small subunit ribosomal DNA (SSU rDNA) was successfully amplified. In summary, we developed a simple technique for the high-yield extraction of purified DNA from a single ciliate cell that may be more useful for rare ciliates, such as tiny and uncultivable marine microbes.

• Korean Journal of Environmental Biology
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• v.28 no.2
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• pp.79-85
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• 2010

To examine the effect of Codium fragile on blood cholesterol and lipid metabolism, hyperlipidemia was induced in experimental animal rats through the administration of a hypercholesterolemic diet. Codium fragile powder was then administered to the rats for 5 weeks, after which, blood biochemical changes such as blood cholesterol, Aspartate Aminotransferase (AST: serum SGOT) and Alanine Aminotransferase (ALT: serum SGPT) enzyme activity, etc. were determined. And histological changes in liver cells were examined using an electron microscope. Codium fragile treatment resulted in a significant reduction of the levels of total cholesterol, blood triglyceride and low-density cholesterol (LDL. Chol) compared to the control rats. In contrast the expression levels of high-density cholesterol (HDL. chol.) were increased. The AST value of the Codium fragile administration group was significantly reduced and the blood ALT value of the Codium fragile group showed a significant decrease in comparison to the negative control group. In summary, this study demonstrated the beneficial possibilities of Codium fragile in improving the abnormality of lipid metabolism caused by liver cell damage and hyperlipidemia.

• Animal Systematics, Evolution and Diversity
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• v.31 no.3
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• pp.153-159
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• 2015

A terebellid polychaete identified as Pista shizugawaensis Nishi and Tanaka, 2006, whose species validity has been doubted, is newly reported from the southwest coast of Korea. Korean materials of the present study have several characteristics that agree well with the original description of P. shizugawaensis as follows: two pairs of branchiae on the 2nd and 3rd segments have tufts composed of many dichotomously branched filaments; the nephridial papillae are present on the 6th and 7th segments; the uncini on the anterior and middle thoracic segments possess only long-handled shafts while those on the posterior ones have additional short-handled shafts or lacking shafts; the notosetae are broadly or narrowly winged capillary. The authors examined the taxonomic value of the presence of lateral lobes on the 5th and 6th segments, which has been known as a key characteristic feature of P. shizugawaensis in the classification of Pista species. In the present study, several characteristics such as the shape of notosetae, uncinial shafts in the thoracic segments, and the presence of thin narrow lateral lobes on the 4th segment are suggested as the specific characteristics that help to distinguish P. shizugawaensis from its congeners. A key to Pista species from Korean waters is also provided.

• Animal Systematics, Evolution and Diversity
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• v.28 no.1
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• pp.20-28
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• 2012

Two urostylid ciliates, Anteholosticha pulchra (Kahl, 1932) Berger, 2003 and Metaurostylopsis struederkypkeae Shao et al., 2008, new to Korea, were collected from the Yellow Sea and the East Sea, Korea, respectively. They were identified based on live observation and protargol impregnation. Taxonomical characters of A. pulchra are as follows: $190-300{\times}30-55\;{\mu}m$ size in vivo; contractile vacuole located on the left side of the posterior 1/4 of the cell; spherical-reddish granules at cirral bases and around dorsal bristles, somewhat sparsely distributed throughout the cell surface; four frontal and two frontoterminal cirri; four dorsal kineties; caudal cirri absent. Metaurostylopsis struederkypkeae is characterized as follows: $80-110{\times}40-50\;{\mu}m$ size in vivo; caudal cirri absent; two types of cortical granules: type 1, yellow-green arranged along the ventral cirral rows and dorsal kineties; type 2, small and reddish, with an irregular arrangement; four frontal, four to eight frontoterminal, and two to six transverse cirri; five to seven left and three to five right marginal rows. Sequences of small subunit ribosomal DNA were determined from both species, and pairwise distances with their relatives were analyzed.

• Animal Systematics, Evolution and Diversity
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• v.28 no.2
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• pp.105-116
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• 2012

Based on samples collected from the Korean Exclusive Economic Zone (EEZ) during an investigation of fishery resources by the National Fisheries Research and Development Institute (NFRDI) from 2002 to 2010, alongside some supplemental material, six species of the genus $Plesionika$ are identified: $P.$ $izumiae$ Omori, 1971, $P.$ $ortmanni$ Doflein, 1902, $P.$ $grandis$ Doflein, 1902, $P.$ $lophotes$ Chace, 1985, $P.$ $narval$ (Fabricius, 1787), and $P.$ $orientalis$ Chace, 1985. Of these, the last four species are new to Korean marine fauna. The distributional range of $P.$ $narval$ extends to the East China Sea off Jeju Island. Excluding $P.$ $izumiae$ and $P.$ $ortmanni$, the other four species are relatively rare in the seas around Korea. They are described and illustrated with color photographs. A key to the Korean species of $Plesionika$ is also presented.

• Animal Systematics, Evolution and Diversity
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• v.36 no.2
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• pp.143-153
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• 2020

Six new species of two genera Dysidea and Pleraplysilla (Demospongiae: Dictyoceratida: Dysideidae) are described from Jejudo Island, Dokdo Island and Guryongpo, Korea. Among them, five new species of the genus Dysidea are compared with other reported species in fibres structure, cored detritus and fibres arrangement. Dysidea niveus n. sp. is characterized by thin collagenous plate-like fibres. Dysidea dokdoensis n. sp. is similar to D. geomunensis Kim et al., 2020 in skeletal structure, but differs in length of surface conules. Dysidea hydra n. sp. is similar to D. mureungensis Kim et al., 2020 at the surface, but differs in fibres cored with spicules. Dysidea sabulum n. sp. is similar to D. glavea Kim et al., 2020 in cored large sands in fibres, but differs in having numerous large sands cored in fibres throughout the sponge. Dysidea hirsuta n. sp. is unique, only surface fibres cored with large sands but not in choanosome. A new species of genus Pleraplysilla, P. flabellum n. sp. is compared with seven other reported species. This new species is not encrusting but has a thick flabellate shape.

• Environmental Analysis Health and Toxicology
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• v.14 no.3
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• pp.81-85
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• 1999

Diazinon, an organophosphate pesticide, is relatively highly toxic to fish and causes vertebral malformation and behavioral change of fish at relatively low concentrations. To elucidate biochemical mechanism of the behavioral change of Oryzias latipes (killifish) caused by diazinon, the effect of the insecticide on acetylcholine esterase activities and the levels of some neurotransmitters were evaluated. Acetylcholine esterase activities in both head and body were significantly lowered at the concentration of 10 ppb of diazinon and acetylcholine contents in head tended to be upregulated with increasing concentration of diazinon. Exposure of killifish to 5000 ppb diazinon resulted in gradual decrease in acetylcholine content in body part with exposure time. Norepinephrine and serotonin concentrations in killifish head and body were highest at 1000 ppb of diazinon while neurotransmitter were relatively low in fish unexposed or exposed to lower dose of the pesticide, suggesting that increased norepinephrine and serotonin can partially account for diazinon-induced behavioral abnormality.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.43 no.4
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• pp.340-344
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• 2010

Identification of individuals is a standard tool used to study animal behavior and ecology. Numerous studies based on photographic identifications of various marine mammal populations have been successfully conducted. The objective of this study was to validate a photo-identification method for spotted seals. We tested the method using 4,939 photographs gathered in 30 field surveys from 2006 to 2008 on Baekryongdo, Korea. In 2006, 20 individuals were identified and cataloged using unique spot patterns on their left chick pelages as a natural marker. In 2007 and 2008, three and nine individuals, respectively, were recaptured, with six individuals continually recaptured during the entire survey period. We confirmed that the spot patterns of spotted seal pelages were constant in shape and location throughout time. These characteristics offered an opportunity to consistently identify individuals within a population over the long survey period. The use of photo-identification has great potential for mark-recapture studies.