• 한국해양학회지
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• v.26 no.3
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• pp.181-192
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• 1991

Zooplankton were sampled horizontally with a standard net from the surface layer of the estuarine system of Mankyong River and Dongjin River in October, 1989, March, May, and July, 1990. Among dominant taxa of the zooplankton community, copepods were predominant in October, 1989 and March, 1990 and Noctiluca scintillans in May and July, 1990. Abundance of zooplankton showed considerable spatial and temporal fluctuations with a range of $12~9,256ind./m^3$ in wet weight. In the copepod community, Pseudodiaptomus inopinus and Paracalanus inducus were predominant in October, 1989: Acartia hudosonica and P. inducus in March, 1990; A. hudosonica and Centropages abdoinalis in May, 1990; A. pacifica, P. indicus and Tortanus spinicaudatus in July. 1990. In summer (July),there were large seasonal changes in salinity ($0.7~28.9\textperthousand$), due to monsoonal flooding, and associated changes in community structured of copepods. There were eight species of copepods in the mixo-mesohaline zone ($5.0~28.8\textperthousand$), namely Acartia pacifica, A. hudosonica, Centropages tenuiremis, C. abdominalis, Labidocera Euchaeta, Tortanus spinicaudatus, corycaeus affinis and Paracalanus indicus. On the other hand, Thermocouple hyalinus, Pseudodiaptomus inopinus and Sinocalanus tenellus occurred in the mixo-oligohaline zone ($0.5~5.0\textperthousand$), showing more tolerant of low salinity than any of the other species. In the mixoeuhaline zone ($>28.0\textperthousand$), Labidocera bipinnata, Oithona similes, Calanus sinicus, Acartia omorii and Tortanus forcipatus were founded.

• 한국해양학회지
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• v.27 no.1
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• pp.11-18
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• 1992

To study on feeding behavior of copepods, Calanus sinicus and Acartia clausi(A. omorii), variations of filtering rate and rate of food intake with the changes of phytoplankton concentrations and time progress were measured in laboratory. Filtering rates of the two species of copepod declined with increasing of the food concentration and the averaging filtering rates C. sinicus and A. clausi were 2.42m/ copepod/hr., 3.37 ml/copepod/hr. respectively. And the rates of food intake increased with food concnetration up to a critical concentration. At higher concentrations, the rates of food intake were somewhat variable but kept the constance levels. Filtering rates of copepods with time progress didn't show diel feeding rythms and generally decreased. But filtering rate of A. Clausi increased by the increment of feeding in a few hours. consequently, two copepods showed similar tendency in the rate of food intake and filtering rate with phytoplankton concentrations. However, the measured values appeared differently. And the two species of copepod with time progress showed the non-continuous feeding behavior.

• Korean Journal of Environmental Biology
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• v.37 no.3
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• pp.299-308
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• 2019

The occurrence patterns of Acartia(Copepoda; Calanoida) species, A. erythraea, A. hongi, A. hudsonica, A. ohtsukai, and A. sinjiensis, were examined in the southern coastal waters of Korea in the summer in August 2012. The Acartia species had different spatial distribution according to environmental factors. A. erythraea showed higher density in a semi-closed bay (Gamak, Masan) where the dissolved oxygen was low (<2 mg L^-1). A. sinjiensis showed a high density in a semi-closed bay when the chlorophyll-a concentration was >2 ㎍ L^-1. A. ohtsukai showed a high density at water temperatures >26℃ and low salinity <30. A. hongi and A. hudsonica showed at water temperatures <27℃ and high dissolved oxygen (>5 mg L^-1). These results suggest that environmental factors (temperature, salinity, dissolved oxygen, and chlorophyll-a concentration) may affect the spatial distribution of Acartia species dominant in the southern coasts of Korea in summer.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.31 no.6
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• pp.842-851
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• 1998

Development and growth of Acartia steueri from Ilkwang Bay, southeastern coast of Korea, were determined under various temperatures and food condition (Isochrysis galbana and Dunaliella salina) in the laboratory. Relationship between egg hatching time ($D_E$, day) and temperature (T, $^{\circ}C$) was $D_E=744(T+3.5)^{-1.97}$. Mean hatching success was $88.4\%$ in temperature range of $8.4\~26.2^{\circ}C$. This suggests that A. steueri may be adapted to the temperature ranges in temperate regions. Post-embryonic development pattern was equiproportional rather than isochronal, with longer stage duration of copepodites than that of the nauplii. Stage duration of NI was the shortest of all developmental stages, while the duration of NII was the longest in duration of the other nauplii. Male was morphologically distinguished from female in CIV stage, and male was developed faster than female. Median development time at a given temperature was calculated from the Belehradek equation by proper multiplication of proportional constant for embryonic development. Body carbon weight at $19.1^{\circ}C$ was increased exponentially with time. Mean specific growth rate of nauplii (0.200 $d^{-1}$), except for NI stage, was not significantly different from that of copepodites (0.190 $d^{-1}$), with the lowest rate in NVI stage (0.107 $d^{-1}$), probably due to energy consumption for metamorphosis rather than somatic growth. The results suggest that although the development pattern determined in this study was not identical with Uye's result for A. steueri (e.g. Uye, 1980b), median development time may be applicable to calculate the stage duration of A. steueri in this study area.

• Journal of the korean society of oceanography
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• v.37 no.2
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• pp.76-81
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• 2002

I investigated whether US naval pulp wastes (pulverized paper products), which is planned to be dumped into offshore waters, may affect the ecology of major components of marine zooplankton. The presence of slurry (0.6% concentration - wet weight ; wet weight) did not significantly affect the population growth rates of the heterotrophic dinoflagellate Polykrikos kofoidii fed on Lingulodinium polyedrum, but significantly reduced the ingestion rates of the calanoid copepods Acartia spp. on L. polyedrum and those of the copepod Calanus pacificus on Akashiwo sanguinea (previously Gymnodinium sanguineum). However, C. pacificus, originally exposed to 0.6% slurry for 24 hour, can recover its feeding rates when slurry disappears. Therefore, if slurry is diluted quickly due to trubulence after being dumped at 0.6% concentration, its presence may not affect Calanus. Chemicals leached from slurry did not affect the feeding rate of Calanus. Therefore, mechanical interference by slurry on the feeding and/or swimming of copepods may be mainly responsible for the reduction of the ingestion rates.

• Ocean Science Journal
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• v.43 no.3
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• pp.135-146
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• 2008

The monthly distribution of zooplankton communities in Han River estuary was investigated at two stations from July 1998 to June 1999. Monthly mean abundance of total zooplankton varied remarkably, with the range from 20 $indiv.{\cdot}m^{-3}$ to 19,600 $indiv.{\cdot}m^{-3}$. During the study period, dominant species of zooplankton community were dinoflagellate Noctiluca scintillans, copepods Paracalanus indicus, Paracaanus crassirostris, Acartia hongi, Acartia ohtsukai, and meroplanton cirriped larvae. According to tidal states, relative high abundance occurred at high tide without regard to season. The temporal distribution of abundance implied that the reduced salinity probably limited the zooplankton populations and the fluctuations of salinity were an important factor in the variation of abundance. However, the results of salinity tolerance test shows that the variations in salinity do not directly influence the decrease of abundance. This study shows that the relatively high abundance of zooplankton near high tide seems to be related with the expansion of abundant zooplankton inhabiting Incheon coastal waters through tidal currents.

• Proceedings of the Korea Society of Environmental Biology Conference
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• 2002.11a
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• pp.154-162
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• 2002

인간이나 환경에 해로운 영향을 주는 지속성 유기오염물질의 독성을 동물플랑크톤 중 요각류를 대상으로 실험하였다. 실험에 사용된 요각류는 장목만에서 주로 가을에 많은 출현을 보인 Acartia erythraea와 늦가을부터 그 다음해 봄까지 우점하는 A. omorli였다. 지속성 유기오염물에 대한 요각류의 독성을 평가하기 위해 3가지의 실험을 실시하였다. 광양만에서 주로 나타나는 5가지 PAHs에 대한 A. omorli 48h-LC50을 구하였고, 온도에 따른 Benzo(a)pyrene과 TBT의 독성의 변화를 Brine shrimp(Artemia)를 이용해 실험하였으며, PAHs 중에서 독성이 강한 Benso(a)Pyrene에 노출된 먹이를 섭취한 Acartia erythraea와 A. omorli의 egg Production, hatching rate, fecal Pellet의 변화를 측정하였다. A. omorli의 48h-LC50으로 조사된 결과 Fluoranthene과 Benzo(a)pyrene의 독성이 강하게 나타난다. 온도실험에서는 동일한 유해물질을 가지고 실험을 하더라도 온도의 변화에 따라 급격한 독성의 차이가 나타날 수 있고, 유해물질간에도 온도에 따라서 나타나는 독성에 대한 특성이 다르게 나타났다. Benzo(a)Pyrene에 노출된 먹이는 요각류의 egg Production, hatching rate, fecal Pellet에 영향을 미치고 있으며, 특히 농도와 실험시간에 따른 부정적 영향들을 보였다.

• Proceedings of the Zoological Society Korea Conference
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• 1996.10a
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• pp.158.2-158
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• 1996

No Abstract, See Full Text

• Proceedings of the Korean Society of Fisheries Technology Conference
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• 1998.06a
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• pp.306-306
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• 1998

• Korean Journal of Fisheries and Aquatic Sciences
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• v.26 no.5
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• pp.424-437
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• 1993

About three fourths of total variability of zooplankton in Asan Bay was associated with season and the difference between inner bay and outer bay was relatively small. However, the differences in percent compositions of major taxa at inner bay and outer bay increased gradually with time, suggesting the change of ecosystem in this bay due to the human exploitation such as reclamation. Seasons of maximum abundances were different among the taxa but consistent for each taxon throughout the three survey years. Calanus sinicus and Acartia bifilosa showed maximum abundance in spring. Sagitta crassa, Paracalanus parvus, A. pacifica, Tortanus spinicaudatus, Corycaeus affinis and Decapoda larva were most abundant in summer. Labidocera euchaeta and Bivalve larva appeared most abundantly in fall. But in winter no taxon showed maximum. In general, low abundance with many species in fall, low abundance and few taxa in winter, increase in both number of taxa and abundance in spring, and high abundance and many taxa in summer were observed. A hypothesis for the observed patterns was suggested although more evidences were needed to support this.