• Journal of Aquaculture
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• v.11 no.2
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• pp.261-269
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• 1998

The harpacticoid copepod, Tigriopus japonicus is one of the important zooplankton as a live food the production of marine fish fry. This reserch was carried out to investigate the culturing method and dietary value of T. japonicus. The reproduction of this copepod was analysed in the culturing systems (tne opened and the closed systems) and the surface area of the substate plates for the mass culture. Survival rate of the mature female and the number of nauplii produced per female for two day was higher in the open culturing system than in the close system. However, the result of survival rate of the nauplius was reversed. Larger surface area of the culturing vessel accommodated higher density of this bentic copepod. In polyculture of T. japonicus and rotifer (B. plicatilis), growth of T. japonicus seems to be dependent on the rotifer density. But rotifer seems to be independent on the copepod. With regard to dietary value, this copepod is better than Artemia nauplius for the larvae of red sea bream and tiger puffer which feed by picking. However, it is inadequate for bottom fish larvae as flounder.

• Environmental Analysis Health and Toxicology
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• v.23 no.2
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• pp.93-100
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• 2008

The ecotoxicological effects of 4-tert-octylphenol were observed on Harpacticoid copepoda Tigriopus japonicus s.l. gathered and cultured from tidal pool of Korean coast. There were no significant differences in survival rate (except 10 $\mu$g/L; 70.00%) and sex ratio (except 30 $\mu$g/L) on T. japonicus s.l. exposed to 4-tert-octylphenol. However, 4-tert-octylphenol induced developmental delay (copepodite emergence day and adult male mergence day) and retardation of first brooding day of adult female. Moreover the body size and biomass decreased at 4-tert-octylphenol exposure. As a result, detailed life-cycle research of T. japonicus s.l. may yield potential bioindicators for environmental monitoring and assessment.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.23 no.6
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• pp.439-442
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• 1990

We have examined harpacticoid copepods inhabiting the phaeophyte Miyok, Undaria pinnatifida (Harvey), on the southern coast of Korea and cultured in the laboratory pieces of Miyok frond heavily infested by frond-mining nauplii to identify the harpacticoid copepod to which those nauplii belong. Of the harpacticoids found in Miyok-washings, only Amenophia orientalis Ho and Hong and an unidentified species of the genus Scutellidium occurred consistently in all Miyok samples examined. Many females of both species carried egg sacs. In the cultures the frond-mining nauplii developed, in 15 days at$15^{\circ}C$, into cope-podid stages or adults that were all identified with Amenephia orientalis. It is therefore concluded that this species is the causative agent for the so-called pinhole disease of the cultivated Miyok on the southern coast of Korea, which is diagnosed by the appearance on the thallus of numerous pinholes occupied by developing nauplii.

• Korean Journal of Ecology and Environment
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• v.41 no.1
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• pp.81-89
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• 2008

The eco-toxicological effects of endocrine disrupter, 4-nonylphenol (4NP) were observed and detected on the harpacticoid copepod, Tigriopus japonicus s.l. obtained and cultur-ed from our coast. There were no significant differences survival rate, sex ratio, and fecundity on T. japonicus s.l. at as low as $30{\mu}gL^{-1}$ of 4 NP exposure. Whereas, 4NP induced developmental delay, decreasing biomass and body size of nauplius and copepodite. Also, Differentially Expressed Gene (DEG) was conducted to detecting gene expression for potential biomarkers response to 4NP. As a result, full lifecycle research on morphology and gene expression of T. japonicus s.l. suggested potential bioindicators or biomarkers for environmental monitoring and assessments.

• Animal Systematics, Evolution and Diversity
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• v.21 no.1
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• pp.31-43
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• 2005

Three harpacticoid species of the genus Onychocamptus are reported from the inland waters of South Korea: O. vitiospinulosa (Shen and Tai), O. mohammed (Blanchard and Richard) and O. bengalensis (Sewell). Of these, O. vitiospinulosa and O. mohammed are newly added to Korean copepod fauna. Onychocamptus vitiospinulosa is redescribed. Systematic accounts on the morphological details and the intraspecific variabilities are provided with a key to the Onychocamptus species from Korea.

• Animal cells and systems
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• v.2 no.2
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• pp.203-208
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• 1998

A new species of harpacticoid copepod Alteuthoides affinis associated with the sponge Callyspongia elegans (Thiele) was collected from offshore waters of Cheju Island, Korea, and is described with illustrations. In this genus, only one species, A. kootare Hicks, has been known to occur in association with an hexacnellid sponge from New Zealand. The new species is similar to A. kootare in the general morphologies such as the shape of body, oral appendages, and thoraxic legs. However, it can be separated from A. kootare by the expanded genital double semite, P1 exopod bearing only one claw without reduced accessary nail, and acute rostrum.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.21 no.1
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• pp.50-56
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• 1988

In order to fine some proper bacterial food for Tigriopus japoncus, bacterial flora of the tide pool inhabited by the copepod has been isolated and tested as bacterial food. Food effect and optimum density of the bacteria in terms of survival rate of the copepod was measured in the larval and the adult stages. Among the 264 strains of isolated bacteria, Acinetobacter spp. Moraxella, spp., Flavobacterium spp. and Pseudomonas spp. were certified as effective food for the copepod. According to the experimental results, Acinetobacter spp. AG-3 was the most effective food for all the stages from nauplius to adult, while Moraxella spp. and Flavobacterium spp. were effective for copepodite stage, and Pseudomonas spp. for the adult stage only. The optimum density of bacteria for the food was about $10^6\;cell/ml$, which was the same average density of bacteria in the tide pool.

• Journal of Marine Life Science
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• v.1 no.2
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• pp.121-125
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• 2016

This study examined the feeding response of the harpacticoid copepod, Tigriopus japonicus exposed to WAF or CEWAF to understand whether decreased feeding of the copepod by oil exposure is induced by food avoidance or medium toxicity. In the medium without WAF, there was no difference in the ingestion rate of the copepod among all polluted diets those were exposed to different concentrations of WAF. The present of WAF in the medium however caused a decrease in the ingestion rate at 100% WAF treatment. In the mixed diet treatment with adhesive diatoms and Tetraselmis suecica, T. japonicus had significantly lower ingestion rate on adhesive diatoms than on others in the medium with CEWAF. As a result, decreased ingestion of T. japonicus by oil exposure was caused by oil toxicity in medium, which may not have directly related with an avoidance of polluted food organisms.

• Journal of the Korean Society for Marine Environment & Energy
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• v.9 no.3
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• pp.160-167
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• 2006

Harpacticoid copepod Tigriopus japonicus is widely distributed in coastal waters of Korea and plays important role in marine trophic structure as a first consumer. In this study, a series of experiment were conducted to test the potential of the species as a standard test species for marine bioassay. Tolerance on salinity and pH, sensitivity on the reference materials(copper sulfate and cadmium chloride) and response on the ocean dumping materials(waste sludge) we re tested to identify if the species satisfy the basic criteria as standard species for marine bioassay. The nauplius of the species($100{\sim}200{\mu}m$) showed wide tolerance on salinity with >90.0% survival rates exposed to $5.0{\sim}35.0psu$ for 48 h. Wide adaptability on pH's were also observed from 6.3 to 8.2 with >90.0% survival rates during the test. $LC_{50}$ values for copper sulfate and cadmium chloride were $3.6{\pm}0.7ppm,\;1.7{\pm}0.8ppm$, respectively. The variations in mortality between replicates were less than 10.0%. Comparison of $LC_{50}$ values indicated that T. japonicus nauplius was lower sensitive to copper sulfate than the most marine crustaceans included copepods, however, the sensitivity of test animal to cadmium chloride higher than the adults of copepod T. japonicus, Paracalanus parvus, and marine rotifer Brachinonus plicatilis. There were significant concentration-response relationship in the mortality of T. japonicus nauplius using the elutriates of three ocean dumping materials(industrial waste sludge). 48 h $LC_{50}$ values we re $31.1{\pm}1.1%$ for the elutriate of sludge from leather processing company and $54.4{\pm}15.1%$ for that of dye production company. Based on the above experimental results, bioassay using benthic harpacticoid T. japonicus nauplius must be a good estimation tool for marine ecotoxicological assessment of waste or chemicals. Wide tolerance on the salinity and pH, and significant linear relationship between concentration and response(mortality) supported the high potential of the species as a standard test species.

• Korean Journal of Environmental Biology
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• v.36 no.4
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• pp.456-462
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• 2018

The purpose of this study was to assess cross-generational effects of bisphenol A exposure in benthic copepods, Tigriopus west. Nauplii (<24 hours old) were exposed to graded concentrations of bisphenol A, and toxicity end-points such as survival, development, sex ratio, and fecundity were measured. $F_1$ generations were grown under innoxious conditions, and similarly assessed. Significant differences were observed in development of nauplii and copepodites, between exposed and non-exposed copepods; however, there were no differences in survival of nauplii or copepodites, sex ratio, or brooding rate in parental generation. In contrast, in the $F_1$ generation, there were significant differences between the control group and exposed group in survival and development of nauplii. Length, width, and biomass of parental and $F_1$ generations were reduced in the exposed group compared to the control group. In addition, some deformities, such as swelling of the prosome, abnormally shaped egg sac, and dwarfism were observed after exposure to bisphenol A. So, our study demonstrates that a cross-generation toxicity test and monitoring of morphological deformities in harpacticoid copepods, can be useful for development of potential bioindicators for environmental monitoring, and assessment of chemical impact.