• 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.

• Environmental Analysis Health and Toxicology
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• v.25 no.3
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• pp.197-205
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• 2010

The ecotoxicological effects of two antibiotics, fenbendazole and lincomycin, were observed in the harpacticoid copepod Tigriopus japonicus s.l. collected from tidal pools in the southern coast of Korea. Fenbendazole had a significant effect on the survival rates (p < 0.05), delay of copepodite emergence, and urosome size (p < 0.05). Lincomycin, on the other hand, had no significant influence on these environmental indicators. However, our analysis of morphological abnormalities in T. japonicus s.l. showed that lincomycin was more effective than fenbendazole in causing deformities. The pattern of deformity was diverse, with fused segments, and loss or addition of setae in the swimming legs. All of these patterns appeared as a result of relatively low concentrations of this antibiotic (0.3, $1\;{\mu}g\;L^{-1}$). We report here patterns of morphological abnormality in T. japonicus s.l. exposed to antibiotics, and suggest their possible application in ecotoxicological monitoring.

• Korean Journal of Environmental Biology
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• v.23 no.2 s.58
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• pp.129-134
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• 2005

The aim of this study was to evaluate the attach rate and survival rate for the female harpacticoid Tigriopus japonicus response to 4-nonylphenol, known endocrine disrupter. The organisms were sampled by net sweeping on the Jeju Island in April, 2004 were reared in the laboratory condition. As the concentrations increased, the mortality was slowly increased. The first day for appearing dead individuals was clearly different between control conditions and treated conditions. When the female with egg sac was moved to experimental conditions for the adaptation, the female was dropped the egg sac from the body and then reproduced the egg sac into four to five days. Usually the female in control group recovered egg sac but that in the treated group made egg sac between $89\%\;and\;95\%$ on exposed individuals. The dead individuals for control conditions were showed on ten days after treating chemicals while those for treated conditions were appeared four to six day after exposure to chemicals.

• 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.

• 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.

• Environmental Sciences Bulletin of The Korean Environmental Sciences Society
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• v.1 no.1
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• pp.61-67
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• 1997

The effects of Insect growth regulator Dimilin which interfere with the synthesis of chitin in the cuticle of insect larvae were investigated at various concentrations using the copepod larvae of Tigriopus japonicus Mori. The larvae were cultured at control, 1, 5, 10, 20, 50, and 100 ppb Dimilin solutions and three replicate experiment were carried out to give correct analysis. Lethal effects of Dimilin on larvae of T. japonicus occurred above 1 ppb Dimilin solution after 8 days. $LC_{50}$ of larvae was 50 ppb Dimilin on the 4th day. Lethal effects of Dimilin on adults or T. japonicus occurred above 20 ppb Dimilin solution after 13 days. $LC_{50}$ of adults was 50 ppb Dimilin on the 12 days. Egg viability has little relation to Dimilin solution concentrations.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.42 no.3
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• pp.268-275
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• 2009

The survival and growth of marine benthic invertebrate larvae such as abalone depend on the nutritional value of micro algae. However, it is difficult to determine the dietary value of the many microalgal species used for food by benthic larvae. Therefore, we tested the benthic copepod, Tigriopus japonicus, which grazes microalgae on substrata in a manner similar to abalone larvae. It also has short generation time and is easy to rear which makes to be easier to examine the dietary value of each micro algal species. We measured the daily production of nauplii from gravid females of T. japonicus fed 26 microalgal species separately. Amino acid and fatty acid content of the micro algae and the copepod was also analyzed. The nauplii production of T. japonicus was the highest (10.7) when they were fed Navicula sp. (B-394) and the lowest (0.8) when they were fed Scrippsiella trochoidea. In Tetraselmis suecica the nauplii production was so high (8.2), which was not significantly different with the diatom group. We determined that Navicula sp. (B-394), Rhaphoneis sp. and T. suecica were good sources of food for T. japonicus. We suggest that a diet of with a mixture of these three micro algal species may be also good for invertebrate larvae such as abalone.

• 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.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.24 no.2
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• pp.117-122
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• 1991

Microbial organisms including yeast, Acinetobacter sp. AG-3, Chlorococcum sp., Chlorella sp. and some of their combinations were tested to evaluate growth efficiency of Tigriopus japonicus. Body length and weight of the copepoda were measured during four days experiment. Acinetobacter sp. AG-3, dried yeast(produced Wago), Chlorella sp., Chlorococcum sp. and mixed culture were used as food sources. Yeast(Y.) was the most effective food for the growth during nauplius stage and efficiencies of bacteria(Bact.)+chlorococcum sp.(RA), Chlorococcum sp.(RA), Bact.+chlorella sp.(Ch.), Bact. and Ch. decreased in odor, while for the growth of copepodite and adult, Bact.+RA was the most effective food with decreased efficiency of Y., RA, Bact. + Ch., Bact., Ch. in order. The ratio of weight gain to the food uptaken, after the weight and food units were converted to carbon, was between 21.6 and $68.7\%$, This result suggests that some kinds of bacteria, algae and mixed cultural microorganisms could be good food sources for the growth of copepoda.

• Ocean and Polar Research
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• v.32 no.4
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• pp.369-377
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• 2010

To characterize ecotoxicological responses to a natural estrogen, $17{\beta}$-estradiol, we evaluated the life-history of the parental ($F_0$) and first generation ($F_1$) of the harpacticoid copepod, Tigriopus japonicus sensu lato. We evaluated the survival of nauplii and copepodites, the number of days until the emergence of copepodites and adult males, the sex ratio, brooding success, and the first brooding day of adult females. No significant differences in the survival rate were noted in response to treatments with different concentrations of $17{\beta}$-estradiol. However, $17{\beta}$-estradiol induced developmental delay and skewed the sex ratio toward males. Copepod development was delayed significantly in the 0.1 and $1\;{\mu}g\;l^{-1}$ $17{\beta}$-estradiol treatment groups relative to the control group, with a more pronounced delay in the $F_1$ group. Body length and biomass were significantly smaller in the $17{\beta}$-estradiol treated groups than in the controls. The male emergence of T. japonicus s.l. was very high in the 10 and $30\;{\mu}g\;l^{-1}$ $17{\beta}$-estradiol treatment group. Furthermore, exposure to $17{\beta}$-estradiol resulted in morphological deformities such as shrinking and swelling of the urosome, twisted setae of the caudal rami, setal loss of swimming legs, abnormal segmentation of antennules, and dwarfism.