• Journal of Environmental Science International
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• v.20 no.11
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• pp.1383-1394
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• 2011

Environmental impacts of suspended solids (SS) released in coastal area by dredging, reclamation and construction can cause serious damages to coastal habitats and benthic organisms. Acute toxicity tests (4-7 days) were conducted to identify the relationship between SS concentration and mortality of three marine benthic species; benthic copepod (Tigriopus japonicus) adult, Pacific abalone (Haliotis discus hannai) spat, and olive flounder (Paralichthys olivaceus) fry. Benthic copepod was the most sensitive to SS followed by olive flounder fry and Pacific abalone spat, with an $LC_{50}$ (lethal concentration of 50% mortality) value of 61.0 mg/L and LOEC (lowest observed effective concentration) value of 31.3 mg/L for benthic copepod. LOEC and 7 day-$LC_{50}$ for Pacific abalone spat were 500.0 mg/L and 1887.7 mg/L, and those for olive flounder fry were 125.0 mg/L and 156.9 mg/L, respectively. The tolerance limits of the test species to SS revealed the various concentration ranges of SS, which reflects the physiology and ecology of the test species. These results are very valuable for the determination of SS concentration of effluents released into the coastal area by dredging, reclamation and construction etc. Also, sharp increase of SS can cause long-term damages to the benthic and sessile fauna by blanketing of benthic substratum. These experimental procedures for marine bioassay and acute toxicity results can be a useful guideline for practical management planning of SS discharge into coastal area.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.13 no.2
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• pp.129-139
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• 2008

Marine ecotoxicological standard method was applicated using marine rotifer and benthic copepod as primary consumer of marine ecosystem. Marine rotifer, Brachionus plicatilis and benthic copepod, Tigriopus japonicus were designated as standard test species with the endpoints of 24hr neonate mortality (24hr $LC_{50}$) and 48hr population growth (48hr $EC_{50}$) for rotifer, and 48hr nauplius mortality (48hr $LC_{50}$) for benthic copepod. Tests method was referred to those of ASTM (American Society for Testing and Materials) with the replacement of test species which are widely distributed in Korean waters. The two species showed a wide tolerance on salinity ($5{\sim}35\;psu$) and can be easily cultured in small space even they were not as sensitive as in the mortality test using the nauplius of marine invertebrates. However, these species revealed the significant "concentrationresponse relationship" tested with ocean disposal wastes, and reproducibility using cadmium as standard reference material between laboratories. Accordingly, these two species have good potential as test species for marine ecotoxicological test species. Also, we strongly recommend that at least one of these species be included in the test species of "battery test" in marine bioassay.

• 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.

• Korean Journal of Environmental Biology
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• v.20 no.1
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• pp.1-9
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• 2002

Copepods play an important role as a primary consumer in the various aquatic ecosystems. Most of marine benthic copepods belong to the Order Harpacticoida, and are known over 3,000 species in the world. Research on the biodiversity of the benthic copepods are important in the development of the new bio-resources, and the genetic resources. The importances and the prospects of biodiversity research on the mavins benthic copepods are discussed.

• Journal of Environmental Science International
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• v.22 no.3
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• pp.359-369
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• 2013

Chronic effects such as reproduction and population dynamics with elevated $CO_2$ concentration were evaluated using two representative marine benthic species, copepod (Tisbe sp.) and amphipod (Monocorophium acherusicum) adopting long-term exposure. Juvenile copepod and amphipod individuals were cultivated in the seawater equilibrated with control air (0.395 mmol $CO_2$/air mol) and high $CO_2$ air having 0.998, to 3.03, 10.3, and 30.1 mmol $CO_2$/air mol during 20 and 46 days, respectively. After the exposure period, the number of benthic invertebrate was counted with separate larval and juvenile stage such as naupliar, copepodid and adult for copepod, or neonate and adult for amphipod, respectively. The individual number of both test species at each life-stage was significantly decreased in seawater with 10.3 mmol $CO_2$/air mol or higher. Recently, the technology of marine $CO_2$ sequestration has been developed for the reduction of $CO_2$ emission, which may cause climate change. However, under various scenarios of $CO_2$ leaks during the injection process or sequestrated $CO_2$ in marine geological structure, the potential risk to organism including various invertebrates can be expected to exposure. So the results of this study suggested that the detailed consideration on the adverse effect with marine ecosystem can be prerequisite for the marine $CO_2$ sequestration projects.

• 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 Species Research
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• v.12 no.3
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• pp.244-257
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• 2023

The family Ameiridae Boeck, 1865 (Copepoda; Harpacticoida) consists of about 380 species in 47 genera, but only 10 species have been reported in Korea. A benthic ameirid species was collected from the East Sea of Korea. Specimens were identified as members of the genus Ameiropsis Sars G.O., 1907, and this is the first record of the genus Ameiropsis in the Pacific Ocean. Ameiropsis gyeongjuensis sp. nov. is morphologically similar to A. mixta Sars G.O., 1907 and A. longicornis Sars G.O., 1907 from Norway. However, the new species is clearly distinguishable from the others based on the following morphological characteristics: the proximal segment of antennary exopod with a bulge in the middle, and with one pinnate seta; the distal segment of antennary exopod with a thickened, blade-shaped outer seta; and female P5 baseoendopod with five setae and exopod with six setae. An identification key to species is provided for the 11 valid species of the genus Ameiropsis.

• Journal of Aquaculture
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• v.19 no.4
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• pp.305-309
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• 2006

This study was carried out to examine the anesthesia and recovery time of the male and gravid female of marine benthic copepod Tigriopus japonicus at 500, 750, 1,000 ppm of MS-222. We also investigated the survival (%) and the nauplii production of T. japonicus for 14 days, which was anesthetized with MS-222. As the concentration of MS-222 was higher, the anesthesia time of the copepod was shorter and the recovery time was longer. The survival (%) of male T. japonicus was significantly higher than that of the gravid female both in anesthetized and control group. But the survival (%) of the male treated with MS-222 did not show the different survival (%) with the control (0 ppm). In contrast, the survival (%) of the gravid female treated with 750 and 1,000 ppm was significantly lower than that of 500 ppm and control. With regard to hatching, as the concentrations was higher, the number of hatching and total nauplii were lower and interval of hatching was longer. However, the gravid female treated with 500 ppm did not show the significant difference with control. We suggest that 500 ppm of MS-222 is the suitable concentration in isolation of T. japonicus.

• 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.

• Journal of Aquaculture
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• v.6 no.3
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• pp.147-157
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• 1993

The harpacticoid copepod, Tigriopus japonicus is one of the most important zooplankton as a live food for the production of marine fish fry. Thus, the salinity tolerance and the optimum culture environment of this copepod in terms of salinity, temperature and light were examined. The food values of 6 kinds of phytoplankters and 2 kinds of yeast were also investigated for mass culture of this copepod. The results are as follows: After 5 day culture in the experiment of salinity tolerance, the survival rates of the gravid female at $0\%\;and\;90%o\;were\;40\%\;and\;70\%$, respectively. However, at salinity ranging from $2\%o\;to\;80\%o$, high survival rates above $85\%$ were observed. It means T. japonicus is very euryhalinous species. Temperature was more important factor than salinity for the fecundity of T. japonicus. The optimum culture conditions of this species were $24^{\circ}C,\;24\%o$, and 3,000 lux with 24 L: 0D. Under these culture conditions, the average fecundity from a gravid female per spawning was 38 nauplii, and the interval time between spawnings were 2.05 days. Phaeodactylum tircornutum seemed to be the most suitable phytoplankton as a live food for T. japonicus, and the large chlorophyta, Tetraselmis suecica showed the lowest food value among 6 phytoplankters and 2 yeasts. The food value of w-yeast was better than that of baker's yeast, and it is similar to that of phytoplankton such as Amphora sp., Chlorella ellipsoidea and Nannochloris oculata. So, the w-yeast seems to be appropriate food source for mass culture of T. japonicus.