• 한국환경과학회지
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• 제30권10호
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• pp.811-820
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• 2021

The population variation of Spanish mackerel (Scomberomorus niphonius) according to its major prey abundance was analyzed using monthly catches of coastal set net fisheries in the southern waters off Gyeongsangnam-do and eastern waters off Gyeongsangbuk-do of Korea from 2006 to 2019. The abundance of Spanish mackerel and its prey species fluctuated almost simultaneously with time lags of +2 to -2 months between the set net fisheries in the southern and eastern waters. The generalized additive model revealed that the abundance of Spanish mackerel was influenced by its prey species such as hairtail and anchovy in southern waters, and common mackerel and horse mackerel in eastern waters. The model deviance explained 49% and 42% of Spanish mackerel abundance in southern and eastern waters respectively. These results suggest that the abundance of Spanish mackerel is affected by seasonal migratory prey fish species in the coastal areas and can be linked to their northerly migration.

• ALGAE
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• 제30권1호
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• pp.35-47
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• 2015

The marine sand-dwelling dinoflagellate Polykrikos lebourae possesses obvious gold-brown pigmented plastids as well as taeniocyst-nematocyst complex structures. Despite of the presence of the visible plastids, previous attempts to establish this species in culture all failed and thus the unavailability of cultures of this species has posed a major obstacle to further detailed exploration of ecophysiology of the dinoflagellate. Here, we isolated P. lebourae from sandy sediment of an intertidal flat on Korean western coast, successfully established it in culture, and have been maintaining the stock culture over the past 3 years. Using this stock culture, we explored phagotrophy and potential prey resources of P. lebourae, growth and grazing responses of P. lebourae to different prey organisms, the effect of prey concentration on growth and grazing rates and gross growth efficiency (GGE) of P. lebourae when fed three different prey organisms, and the growth kinetics of P. lebourae under different light regimes. P. lebourae captured prey cells using a tow filament and then phagocytized them through the posterior end. The dinoflagellate was capable of ingesting a broad range of prey species varying in size, but not all prey species tested in this study supported its sustained growth. GGE of P. lebourae was extremely high at low prey concentration and moderate or low at high prey concentrations, indicating that P. lebourae grows heterotrophically at high prey concentrations but its growth seems to be more dependent on a certain growth factor or photosynthesis of plastids derived from the prey. In the presence of prey in excess, P. lebourae grew well at moderate light intensity of $40{\mu}mol$ photons $m^{-2}s^{-1}$, but did not grow at dim and high (10 or $120{\mu}mol$ photons $m^{-2}s^{-1}$) light intensities. Our results suggest that the benthic dinoflagellate P. lebourae is an obligate mixotroph, requiring both prey and light for sustained growth and survival.

• 한국수산과학회지
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• 제45권4호
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• pp.379-386
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• 2012

The feeding habits of the Pacific cod Gadus macrocephalus were studied by analyzing the stomach contents of 423 specimens caught by coastal gill net in the coastal waters off Jumunjin, Gangwondo, Korea, from January to December, 2011. The size of Pacific cod ranged from 31.0 to 86.5cm in total length (TL). The proportion of empty stomachs was 25.1%. The main prey items were Macrura, Pisces, and Cephalopoda. In order of abundance, the most dominant species of Macrura, were Pandalus eous, Argis lar, and Neocrangon communis, and the most dominant species of Pisces, were Clupea pallasii, Actoscopus japonicus, and Glyptocephalus stelleri. Berryteuthis magister was the most dominant species of Cephalopoda. In terms of variation in feeding habits by growth, Macrura was the most important prey group for G. macrocephalus ranging in TL from 30- to 55 cm, but Pisces was the most important prey group for cod over 56 cm TL. Catch of G. macrocephalus was significantly positively correlated to catch of the three major Pisces prey species Clupea pallasii, Actoscopus japonicus and Glyptocephalus stelleri.

• Journal of Animal Science and Technology
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• 제56권5호
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• pp.16.1-16.9
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• 2014

Fatty acids (FA) have recently been used in several studies to infer the diet in a number of species. While these studies have been largely successful, most have dealt with predators that have a fairly specialized diet. In this paper, we used FA analysis as a tool to infer the diet of the nearctic river otter (Lontra canadensis). The river otter is an opportunistic predator known to subsist on a wide variety of prey including, fishes, crayfish, molluscs, reptiles and amphibians, among others. We analyzed the principle components of 60 FA from otters and 25 potential prey species in Illinois, USA. Prey species came from 4 major taxonomic divisions: fishes, crayfish, molluscs and amphibians. Within each division, most, but not all, species had significantly different profiles. Using quantitative FA signature analysis, our results suggest that, by mass, fish species are the most significant component of Illinois River otters' diet ($37.7{\pm}1.0%$). Molluscs ranked second ($32.0{\pm}0.8%$), followed by amphibians ($27.3{\pm}4.3%$), and finally, crayfish ($3.0{\pm}0.6%$). Our analysis indicates that molluscs make up a larger portion of the otter diet than previously reported. Throughout much of the Midwest there have been numerous otter reintroduction efforts, many of which appear to be successful. In regions where mollusc species are endangered, these data are essential for management agencies to better understand the potential impact of otters on these species. Our analysis further suggests that quantitative FA signature analysis can be used to infer diet even when prey species are diverse, to the extent that their FA profiles differ. Better understanding of the otter's metabolism of FA would improve inferences of diet from FA analysis.

• 수산해양기술연구
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• 제46권4호
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• pp.406-415
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• 2010

The forming of fishing ground and the population ecological characteristics of yellowtail, Seriola quinqueradiata, in the coastal waters off Gim-nyeong of Jeju Island were investigated. The stock of yellowtail, Seriola quinqueradiata, between Jeju Island and coastal areas of the East Sea is probably the same. Water temperature probably is a major factor for controlling distribution of yellowtails in deeper, offshore areas off Jeju Island. However, the major factor that determines aggregation of yellowtails in coastal areas of Jeju Island, especially off Gim-nyeong is probably strong tidal currents driven by distribution of yellowtails rather than hydrological conditions such as Yellowtails collected off Jeju Island were from 1 to 4yrs old and about 50% of them were $1^{-yr}$ old, probably indicating overfishing. Jack mackerel was the major prey item for yellowtails off Gim-nyeong from October to March, suggesting concurrence of the two species.

• ALGAE
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• 제38권1호
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• pp.57-70
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• 2023

The mortality rate of red-tide dinoflagellates owing to predation is a major parameter that affects their population dynamics. The dinoflagellates Ansanella granifera and Ansanella sp. occasionally cause red tides. To understand the interactions between common heterotrophic protists and A. granifera, we explored the feeding occurrence of nine heterotrophic protists on A. granifera and the growth and ingestion rates of the heterotrophic dinoflagellate Gyrodinium dominans on A. granifera as a function of prey concentration and those of Oxyrrhis marina at a single high prey concentration. The heterotrophic dinoflagellates Aduncodinium glandula, G. dominans, Gyrodinium moestrupii, Luciella masanensis, Oblea rotunda, O. marina, Polykrikos kofoidii, and Pfiesteria piscicida and the naked ciliate Strombidium sp. were able to feed on A. granifera. With increasing mean prey concentrations, the growth and ingestion rates of G. dominans feeding on A. granifera rapidly increased and became saturated or slowly increased. The maximum growth and ingestion rates of G. dominans on A. granifera were 0.305 d^-1 and 0.42 ng C predator^-1 d^-1 (3.8 cells predator^-1 d^-1), respectively. Furthermore, the growth and ingestion rates of O. marina on A. granifera at 1,700 ng C mL^-1 (15,454 cells mL^-1) were 0.037 d^-1 and 0.19 ng C predator^-1 d^-1 (1.7 cells predator^-1 d^-1), respectively. The growth and ingestion rates of G. dominans and O. marina feeding on A. granifera were almost the lowest among those on the dinoflagellate prey species. Therefore, G. dominans and O. marina may prefer A. granifera less than other dinoflagellate prey species. The low mortality rate of A. granifera may positively affect its bloom formation.

• 한국수산과학회지
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• 제32권1호
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• pp.10-17
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• 1999

1994년 1월부터 1994년 12월까지 광양만 대도주변 잘피밭에서 채집된 문절망둑의 식성을 조사하였다. 문절망둑의 주요 먹이생물은 갯지렁이류(Polychaeta), 게류(Brachyura), 새우류(Caridea), 옆새우류 (Gammaridea) 및 어류 (Pisces) 등 다양하였다. 그 외, 거미불가사리류 (Ophiuroidea), 복족류 (Castropoda), 이매패류 (Bivalvia), 카프렐라류 (Caprellidea), 집게류 (Anomura), 등각류 (Isopoda), 주걱벌레 붙이류 (Tanaidacea)등을 소량 먹었다. 문절망둑은 성장함에 따라 먹이생물 조성의 변화를 보였는데, 작은 체장에서는 갯지렁이류와 단각류를 주로 먹었다. 그러나 체장이 증가하면서 갯지렁이류와 단각류를 먹는 비율은 감소한 반면, 새우류, 게류 및 어류의 점유율은 증가하였다. 성어 단계에서는 매우 다양한 먹이생물을 먹는 것으로 나타났다. 계절에 따라 먹이생물의 조성이 변하였는데, 봄과 가을에는 갯지렁이류, 새우류 및 옆새우류의 점유율이 높았으나, 여름과 겨울에는 어느 특정 먹이생물이 우점하지 않고 비교적 고른 분포를 보였다.

• 한국어업기술학회:학술대회논문집
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• 한국어업기술학회 2003년도 춘계 수산관련학회 공동학술대회발표요지집
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• pp.199-200
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• 2003

After more than 5 years of turbot culture in China, low percent survival and high occurrences of abnormally pigmented juveniles are still major problems for fish farmer. Much research has been directed toward determining the optimal feeding strategies and nutritional requirements for marine flatfish larvae, and considerable advances have been made. The most common live feeds include :Artemia, rotifer and copepods. (omitted)

• 한국어류학회지
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• 제20권1호
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• pp.45-53
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• 2008

2005년 1월부터 2005년 12월까지 동대만의 잘피밭에서 채집된 돌팍망둑의 식성을 조사하였다. 돌팍망둑의 주요 먹이는 어류 및 새우류였으며, 그 외, 곤쟁이류, 단각류 (옆새우류 및 카프렐라류), 요각류, 두족류, 갯지렁이류 및 게류등이 소량 섭식되었다. 돌팍망둑은 초기에는 요각류와 단각류를 많이 섭식하였으나, 성장함에 따라 어류와 새우류의 섭식율이 점차 증가하였다. 돌팍망둑은 계절에 관계없이 새우류 및 어류를 주로 섭식하였다. 체장별 및 계절별 dietary breadth는 전체적으로 낮게 나타났다.

• 환경생물
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• 제24권2호
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• pp.138-146
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• 2006

위 내용물 분석을 위하여 경남 통영시 바다목장 해역내 한국해양연구원 가두리 설치 지역에서 2004년 7월부터 8월까지 채집을 실시하였으며, 분석에 사용된 볼락은 점등, 비점등 총 200개체였다. 점등에 의해 유집된 동물플랑크톤중 볼락의 가장 중요한 먹이생물은 요각류(Copepoda), 단각류(Amphipoda)순으로 나타났으며, 비점등구간에서도 역시 요각류(Copepoda), 단각류(Amphipoda)순으로 나타났다. 계절에 따른 먹이조성의 변화를 살펴보면 점등구간의 경우 비점등구간에 비해 비교적 다양한 먹이생물을 고루 섭이하였으며, 특히 점등에 의해 요각류와 단각류의 출현량이 많아 중간육성 기간중 볼락의 위내용물 중 이들이 차지하는 비율이 비교적 높았으며, 비점등구에서는 전조사기간중 요각류의 출현량이 대부분을 차지하였다. 중간육성 기간중 점등, 비점등구간에서 먹이공급 조건에 따른 성장관계를 살펴보면 동일한 조건에서 비점등구에 비해 점등구에서 사육한 볼락의 성장이 양호한 것으로 나타났다.