• 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 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.

• 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 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.

• 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 Aquaculture
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• v.18 no.2
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• pp.86-91
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• 2005

Three haptophyte algae, Isochrysis galbana, Prymnesium parvum and P. patelliferum were offered to the marine copepod Tigriopus japonicus as food. Growth rate of larvae, egg production, mortality and comsumption rates of T. japonicus were measured for each of the haptophyte species offered. The growth rate of larvae, egg production and algal ingestion of T. japonicus fed on P. parvum and P. patelliferum were much lower than those fed on I. galbana and corresponding high mortality rates were also observed during the experimental period. The harmful effects observed during the present study indicate that bloom-forming haptophyte algae, P. parvum and P. patelliferum are not suitable feed species for culture of copepod, T. japonicus.

• 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.

• Journal of Aquaculture
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• v.13 no.1
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• pp.63-67
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• 2000

Tigriopus japonicus harpacticoida copepod was a common copepoda species as food organism for the marine fish larval rearing. However T. japonicus was difficult to stable culture except for a mixed culture with rotifer. Available food source for the successfully stable culture of T. japonicus was investigated in this study. T. japonicus did not utilization Nannochloropsis oculata instead of that. T japonicus utilized to products from rotifer culture tank. The products from rotifer culture tank was composed of rotifer feces and co-existing aquatic bacteria. The nauplius I stafe and copepodid I stage of T. japonicus showed grown whenproducts from rotifer culture tanks was fed. Specially we observed higher density of nauplii than that of copepodites and ovisac carrying females in the experimental culture populations.