• 한국수산과학회지
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• 제44권6호
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• pp.671-676
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• 2011

To determine the optimum light intensity for mass culture of the brackish-water cyclopoid copepod Paracyclopina nana, survival, growth, and productivity of the copepod were examined at several light intensities (0, 10, 100, 500, 1,000 lx). The survival rate of P. nana from nauplius to adult decreased with increasing light intensity. The highest survival rate was found under the dark condition, with 61.7% surviving; no significant difference was observed between 0 and 10 lx (51.7%) and the lowest survival rate was with 100 lx (26.7%). Survival rates at 500 and 1,000 lx were significantly lower in comparison with other conditions. The developmental period from nauplius to copepodid (5.8 days) and to adult (11.8 days) at 10 lx was significantly shorter than in the other treatments. Daily mean nauplius production of adult females over 7 days at 0, 10 and 100 lx was significantly higher than at 500 and 1,000 lx. In the 1,000 lx treatment, 99% of the adult females died on the $14^{th}$ day. The optimum light intensity for the mass culture of P. nana could be 10 lx, which had no adverse effects on survival, development, or reproduction.

• 환경생물
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• 제29권4호
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• pp.379-387
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• 2011

Copepod nauplii plays an important role as a linker between the microbial food web and classical food chain in marine ecosystem and is an essential food source for early stage of many larval fishes. Study on the influencing factors on the growth of copepod naupliar stages has been rarely carried out in despite of these ecological significances. Many studies have shown that food availability and temperature are major factors to influence copepod growth. However, due to the complicated environment parameters in coastal ecosystem, the relationships between growth of copepods and influencing factors are still unclear under the natural condition. Growth rates of the copepod $Acartia$ $hongi$ nauplii were measured in Kyeonggi Bay from February to December 2001. $Acartia$ $hongi$ is numerically abundant and widespread predominant species in the coastal regions of the Yellow Sea and occurs continuously throughout the year, with a maximum peak in late spring. The naupliar growth rates of $Acartia$ $hongi$ by the artificial cohort method varied from 0.03 to 0.18 $day^{-1}$, with a mean of 0.09 $day^{-1}$. The overall naupliar growth rates showed a significantly positive relationship with the variation in water temperature. However, Previous study reported that the growth rates of adult $Acartia$ $hongi$ were primarily influenced by the variation in chlorophyll-$a$. Therefore, these differences demonstrated that the influencing factors of growth did not correspond with the developmental stages. The results of this study suggest that the dissimilarity of growth between nauplius and adult female resulted from the size-dependant difference in food availability and the growth of older developmental stages containing adults are more food-dependent than juveniles.

• Ocean and Polar Research
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• 제45권2호
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• pp.43-55
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• 2023

This study was conducted to understand the seasonal patterns and variation of the copepod community in the Anma Islands of Yeonggwang, Yellow Sea, with a focus on seasonal surveys to assess the factors affecting their occurrence. Throughout the survey period, Acartia hongi, Paracalanus parvus s. l., and Ditrichocorycaeus affinis were dominant species, while Acartia ohtsukai, Acartia pacifica, Bestiolina coreana, Centropages abdominalis, Labidocera rotunda, Paracalanus sp., Tortanus derjugini, Tortanus forcipatus occurred differently by season and station. As a results of cluster analysis, the copepod communities were distinguished into three distinct groups: spring-winter, summer, and autumn. The results of this study showed that the occurrence patterns of copepod species can vary depending on environmental conditions (topographic, distance from the inshore, etc.), and their spatial occurrence patterns between seasons were controlled by water temperature and prey conditions. One of the physical mechanisms that can affect the distribution of zooplankton in the Yellow Sea is the behavior of the Yellow Sea Bottom Cold Water (YSBCW), which shows remarkable seasonal fluctuations. More detailed further studies are needed for clear grounds for mainly why to many Calanus sinicus in the central region of the Yellow Sea are seasonally moving to the inshore, what strategies to seasonally maintain the population, and support the possibilities of complex factors.

• 한국해양생명과학회지
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• 제1권2호
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• pp.121-125
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• 2016

본 연구는 유류오염에 의한 요각류 Tigriopus japonicus의 먹이섭식능력의 감소가 먹이회피에 의한 것인지 오염된 해수의 독성에 의한 것인지를 알아보기 위해, 유류(WAF 또는 CEWAF)에 오염된 먹이에 대한 T. japonicus의 먹이 섭식력을 조사하였다. WAF가 없는 배양수 조건에서는 모든 실험구에서 섭식량의 차이를 보이지 않았지만 WAF가 배양수에 있는 조건에서는 WAF의 농도가 증가할수록 섭식량이 줄어드는 경향을 보여 WAF 100% 농도에서는 대조구에 비해 유의하게 감소하였다. T. japonicus가 CEWAF에 오염된 환경에서 먹이의 종류에 따른 먹이선택성여부를 조사한 결과, 오염된 먹이를 공급했을 때, 배양수에 CEWAF가 존재하는 상태에서, 먹이로 Tetraselmis suecica를 공급한 실험구가 다른 실험구에 비해 유의적으로 낮은 부착규조류 섭식률을 보였다. 결과적으로, 유류오염에 의한 T. japonicus의 먹이 섭식력의 감소는 오염된 먹이회피에 의한 섭식력의 감소가 아니라 해수에 존재하는 유류독성에 의한 것으로 판단된다.

• 한국수산과학회지
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• 제34권1호
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• pp.27-31
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• 2001

보구치 후기자어의 먹이생물과 선택성을 조사하기 위하여 1995년 여름 광양만에서 채집된 보구치 후기자어의 장내용물을 조사하였다. 보구치 후기자어의 장에서 관찰된 먹이생물의 종류는 요각류의 난과 nauplius 유생, 유종섬모충류의 Codonellopsis sp.와 Tintin-nopsis sup. 등이었다. 상대중요성지수에 의하면 보구치 후기자어의 가장 중요한 먹이생물은 요각류 nauplius 유생이었다. 보구치는 성장하면서 섭취하는 먹이의 크기가 증가하였으며, 요각류 nauplius 유생에 대한 선호도도 증가하였다.

• 한국양식학회지
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• 제9권2호
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• pp.117-123
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• 1996

Two species of the copepod parasite were observed from two marine fishes in Korea. A siphonostomatoid copepod Neobrachiella incurva (Shiino, 1956) (Lernaeopodidae) and a cyclopoid copepod Peniculus ostraciontis Yamaguti 1939 (Lernaeidae) were found on the gills of Halichoeres poecilopterus and the fins of Sebastes schlegeli, respectively. The most distinct features of N. incurva are bipartite of maxillule, 2 ventro-posterior processes and conical genital process. P. ostraciontis is very distinguishable in the body shape, antenna, and fused trunk. Both species of copepods are newly observed from the Korean waters.

• 한국수산과학회지
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• 제28권3호
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• pp.247-252
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• 1995

멸치의 초기 먹이생물을 조사하기 위하여 1990년 6월 광양만에서 채집된 멸치의 장내용물을 조사하였다. 멸치는 난황의 흡수를 끝낸 척색장 3.0mm부터 먹이를 먹기 시작하였다. 멸치 자어의 먹이는 요각류의 난과 nauplius 유생, 유종류 등으로 구성되어 있었다. 척색장 3.0-3.8mm의 자어에서는 요각류 난과 요각류 nauplius 유생이 주요 먹이생물이었으나, 척색장 3.8mm 이상에서는 요각류 nauplius 유생만이 관찰되었다.

• 한국수산과학회지
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• 제29권4호
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• pp.450-455
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• 1996

전어 (Konosirus punctatus) 후기자어의 먹이생물을 조사하기 위하여 1990년 6월 광양만에서 채집된 전어의 장내용물을 조사하였다. 전어 후기자어의 장에서 관찰된 먹이생물은 요각류의 난과 nauplius 유생, 유종류의 Tintinnopsis, Codonellopsis 등이었다. 척색장 $4.8\~5.0mm$의 자어에서는 요각류 난과 nauplius 유생이 주요 먹이생물이었으나, 척색장 5.0mm 이상의 자어에 서는 요각류 nauplius 유생과 유종류 Tintinnopsis가 중요한 먹이생물로 나타났다.

• 한국수산과학회지
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• 제24권6호
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• pp.369-396
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• 1991

한국산 양식 이매패류 9종으로부터 9종의 요각류가 발견되어 이들을 기재한다. 이들 요각류 중에는 신종 Lickonnolgus simillis도 포함되어 있다. 그 외의 다른 8종은 다음과 같다 Conchyliurus quintus, Pseudomyicola spinosus, Myicola ostreae, Ostrincola koe, O. japonica, Hemannella longicaudata, Modiolicola bifidus, M. gracilicaudus. 이들 요각류와 숙주와의 관계도 기록한다

• Journal of the korean society of oceanography
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• 제31권3호
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• pp.144-149
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• 1996

I investigated the predation impact by the heterotrophic dinoflagellate Protoperidinium cf. divergens on copepod eggs in the presence of co-occurring phytoplankton prey (a preferred red-tide dinoflagellate Gonyaulax polyedra) and the selective feeding on mixtures of both prey. The ingestion rates of P. cf. divergens on Egg N (unidentified round copepod eggs with a smooth surface, about 80 in diameter) decreased by only 1.7-2 times when mean G. polyedra concentration increased by 57-115 times. In mixed prey experiments, P. cf. divergens preferred Egg N over G. polyedra even at 1.1 ${\mu}g$C $ml^{-1}$ or 470 cells $ml^{-1}$ of the latter. A strong preference of P. cf. divergens for Egg N over G. polyedra can be responsible for this relatively small effect. Protoperidinium may sometimes have a considerable predation impact on the populations of Egg N even during phytoplankton blooms or red-tide periods.