• 한국시스템다이내믹스연구
• /
• 제11권3호
• /
• pp.105-126
• /
• 2010

The ecology of house swallow is closely related to the humans life because their life depend on the human settlements conditions and environments. 30 years ago house swallows are very common at the country side, but recently they are very rare. Almost the number of house swallows decrease as 1 of hundredth during 20 years. Why this dramatic population decrease are happening in the ecology of house swallow? The Population size impacted by many factors such as nesting, breeding, feeding, returning. The objective of this paper is to analyse the population dynamics of the ecology of House Swallow. This paper focuses on the important ecological changes-nests, foods, and return rates from wintering area-associated with recent country side development. In this paper, we explore the feedback loops of population dynamics and simulate the policy scenario model.

• Journal of the korean society of oceanography
• /
• 제37권2호
• /
• pp.76-81
• /
• 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.

• 한국수산과학회지
• /
• 제40권2호
• /
• pp.84-94
• /
• 2007

The comparative feeding ecology of greenling Hexagrammos otakii and Schlegel's black rockfish Sebastes schlereli populations was investigated in the Jangbong tidal flat near Incheon, Korea. Monthly samples were taken using a modified otter trawl from November 1999 to January 2001. The stomach contents of 124 greenling and 115 Schlegel's black rockfish were analyzed. The diet of H. otakii was dominated by the amphipods Gammaropsis iaponicus, Caprella scaura, Isaeopsis sp. and Monocorophium acherusicum, the shrimps Latreutes mucronatus and Alpheus japonicus, the mysid Neomysis orientalis and the bivalve Mytilus edulis. In contrast, S. schlegeli mainly fed on the mysids N. orientalis, N japonica, and N. awatschensis, the shrimps Exopalaemon carinicauda, A. japonicus and L. mucronatus, and the fish Pholis fangi and unidentified gobiids. A comparison of the frequency and abundance of food items showed that crustaceans (e.g. amphipods, mysids and shrimps) were important foods for both species. Their main dietary components, however differed which is probably due to differences in the spatial distribution of the two species and their prey items. In conclusion, greenling and Schlegel's black rockfish, despite being sympatric on a tidal flat have distinct food habits and low dietary overlap (Schooner's index: 0.1). These results indicate, to some extent, resource partitioning for the maximum utilization of available foods in the tidal flat.

• 한국어류학회지
• /
• 제30권2호
• /
• pp.92-99
• /
• 2018

멸종위기종 미호종개 C. choii의 생태학적 특징을 밝히고 복원의 기초자료를 확보하기 위해 섭식생태를 충청남도 청양군 청남면 인양리의 금강지류 지천에서 조사를 실시하였다. 미호종개는 3월부터 10월까지 활동기로, 11월부터 2월까지는 월동기로 나누어졌으며, 활동기에는 주행성 어류로 기질 (모래) 밖으로 나와 활동하였다. 소화관내용물을 상대중요성 지수 (index of relative importance, IRI)로 분석한 결과, 파리목 (Diptera) 69.9%, 요각목 (Copepoda) 23.2%, 꽃병벌레과 (Arcellidae) 2.3%, 새각목 (Branchiopoda) 2.0%, 유영목(Ploima) 2.0% 등의 순으로 높게 나타났다. 크기가 작은 당년생 치어(0년생)는 유영목과 새각목을 주로 섭식하였으나, 성어(2~3년생)는 크기가 큰 깔다구과(Chironomidae)를 주로 섭식하여 차이를 보였다.

• Journal of Ecology and Environment
• /
• 제46권4호
• /
• pp.304-315
• /
• 2022

Background: Filter-feeding zooplankton has limited food resources owing to their habitat. Consequently, it is crucial for them to acquire all essential compounds, such as fatty acids (FAs) and amino acids, from confined diets. To elucidate the trophic transfer of FAs to filter feeders, the primary consumers in freshwater ecosystems, we compared the FA accumulation patterns of two species of filter-feeding zooplankton, Daphnia magna and Branchinella kugenumaensis, in a laboratory experiment. Experimental neonates and nauplii preyed on a single phytoplankton species (Selenastrum capricornutum) for three days after hatching prior to diet switching. Five replicates per feeding group in each species were fed on six different types of mixed phytoplankton diet for 10 days after diet switching. Subsequently, the consumers and diets were harvested and FAs were extracted. Results: Principal component analysis showed that the FA profiles of zooplankton were well-grouped by species and diet. Although diet affects the FA profiles of consumers, they exhibit different FA accumulation patterns. D. magna had a higher 18C-ω3 content and ω3/ω6 ratio than did B. kugenumaensis. In contrast, B. kugenumaensis had higher contents of 18:1ω7 and 20:5ω3 (eicosapentaenoic acid), 22:6ω3 (docosahexaenoic acid), and a higher ratio of ∑18C monounsaturated FAs to ∑18C-ω3 polyunsaturated FAs than did D. magna. Conclusions: This study showed that two primary consumers, D. magna and B. kugenumaensis, fed the same diet had different assimilation patterns of FAs under controlled environments. Specific FA accumulation patterns in filter feeders can provide information on the transfer process of various FAs to high-trophic organisms.

• 생태와환경
• /
• 제50권2호
• /
• pp.266-274
• /
• 2017

멸종위기종 개리(Anser cygnoides)의 월동기 서식지 이용과 먹이원에 대해 연구하였다. 개리는 서천갯벌에 10월에 도래하여 약 6개월간 월동한 후, 다음해 4월초에 월동지를 떠나 번식지로 이동하였다. 서천갯벌에서 월동하는 동안 개리는 뚜렷한 지역 간 이동, 서식지 이용 패턴을 보였다. 즉 도래초기인 10월에는 주로 송림리 갯벌의 매자기류 (Bolboschoenus sp.) 군락지를 집중하여 이용하였으나, 11월부터는 장구만 지역으로 이동하여 연안 갯벌에 일부 존재하는 매자기류 군락지와 인근 농경지에서 섭식활동을 하였다. 배설물에서 추출한 유전자 분석을 통해 개리가 사초과의 매자기류 식물을 월동기간 동안 주먹이원으로 이용한다는 것을 확인하였다. 또한 분포와 섭식지 이용에 변화를 보이는 시기에 사초과 식물 외에도 콩과 식물의 검출양이 증가하였다. 이러한 결과는 개리가 월동기간 동안 섭식하는 먹이원의 이용가능성 변화에 반응하여 서식지를 이용하는 전략을 취하는 것으로 평가된다. 서천갯벌은 개리의 월동지로서 가치가 있으며, 특히 송림리와 장구만 지역에 분포하는 매자기류 군락지는 월동기간 동안 개리가 이용하는 핵심지역으로 보호되어야 한다.

• 한국어류학회지
• /
• 제35권1호
• /
• pp.30-38
• /
• 2023

쌀미꾸리 Lefua costata의 섭식생태를 밝히기 위해 2013년 1월부터 12월까지 강원도 강릉시 옥계면 남양리에서 조사를 실시하였다. 쌀미꾸리는 주로 수온 5℃ 이상 되는 3월부터 12월까지 섭식을 하였고, 섭식률은 4~5월, 9~10월에 정점을 보였다. 위 내용물을 상대중요성지수(IRI)로 분석한 결과, 주로 절지동물문(Arthropoda) 곤충강(Insecta)의 파리목(Diptera, 77.1%), 하루살이목(Ephemeroptera, 20.3%), 날도래목(Trichoptera, 1.7%), 잠자리목(Odonata, 0.4%)이었으며, 그 외 먹이생물은 환형동물문(Annelida)의 턱거머리목(Arhynchobdellida, 0.6%)과 실지렁이목(Tubificida, 0.1%), 선형동물문(Nematoda, 0.2%), 어류(Actinopterygii, 0.1%), 연체동물문(Mollusca)의 백합목(Veneroida) 등 다양하였다. 계절별로 보면, 봄에는 파리목(55.4%)과 하루살이목(41.6%)을, 여름에는 파리목(92.7%)과 환형동물문(Annelida, 6.8%)을, 가을에는 파리목(70.8%)과 하루살이목(9.0%), 날도래목(8.1%), 환형동물문(7.7%)을 주로 섭식하였다. 연령별로 보면 당년생 치어(0+)는 비교적 먹이 크기가 작은 파리목(주로 깔따구과(Chironomidae), 98.2%)만 거의 섭식한 반면, 성장하면서 파리목의 비율이 점점 감소하고 비교적 크기가 큰 하루살이목과 환형동물문의 비율이 증가하였다. 먹이 생물 크기는 당년생 치어(0+) 2.5±1.05 mm, 1년생(1+) 3.2±1.29 mm, 2년생(2+) 3.7±2.05 mm, 3년생 이상(≥3+) 6.8±4.97 mm로 성장하면서 급격히 커지는 경향을 보였다.

• 한국환경생태학회지
• /
• 제26권3호
• /
• pp.333-341
• /
• 2012

맹꽁이(Kaloula borealis)의 먹이 습성을 밝히기 위하여 2011년 6월에 제주도 대정읍 일대에서 채집된 56개체에서 52개체의 먹이를 조사하였다. 위 속의 먹이는 Stomach Flushing Method를 이용하여 분석하였다. 분석결과, 맹꽁이(Kaloula borealis)의 주요 먹이는 파리류, 먼지벌레류, 개미류, 초파리류로 나타났다. 부피가 작은 먹이는 다양한 크기의 개체들이 포식을 하고 있으나, SVL이 큰 개체들은 부피가 큰 먹이들도 포식하여 에너지 효율성을 높이고 있다. 맹꽁이(Kaloula borealis)는 비행능력이 있고 활동적인 파리류나 초파리류를 먹이로 많이 이용하고 있는 것으로 보아 이들은 활발히 움직이면서 먹이를 포식하기보다는 기다리다가 포식하는 형태인 것으로 나타났다. 이번 연구를 통해 얻어진 맹꽁이(Kaloula borealis)의 먹이습성에 대한 연구 자료는 급격히 감소되어가는 이들의 보호와 개체군 보존전략에 대한 대안을 마련하는데 유용하게 활용될 것이다.

• Journal of Ecology and Environment
• /
• 제37권4호
• /
• pp.225-229
• /
• 2014

Feeding behavior of Temora turbinata was investigated through laboratory experiments with special emphasis on its food preference and consequent clearance rate on diatom and microbial components given as common natural food assemblage of coastal area (Uchiumi, Uwa Sea, Japan). Among available prey items, T. turbinata showed the highest clearance rate for Thalassiosira spp. ($0.23{\pm}0.08L\;Temora^{-1}day^{-1}$) followed by Chaetoceros spp. ($0.11{\pm}0.03L\;Temora^{-1}day^{-1}$), but clearance rates for other diatom, Nitzschia spp. was lower (0.03 to $0.07L\;Temora^{-1}day^{-1}$). Bacterial abundances showed no response against 24-h feeding of T. turbinata. Feeding of T. turbinata on heterotrophic nanoflagellates (HNF) was apparent when clearance rates of T. turbinata on diatoms were relatively low, but T. turbinata did not consume HNF as well as ciliates with Thalassiosira spp. of which clearance rate was highest. The results suggest that HNF and ciliates are possible supplementary prey item for T. turbinata, but their contribution as food sources can be limited by the presence of other prey items such as preferable diatom species.

• Ocean Science Journal
• /
• 제42권3호
• /
• pp.193-197
• /
• 2007

The food selectivity of tethered females of the copepod Calanus helgolandicus was examined by using the colorimetric approach. First, feeding behavior of the copepod did not show any differences between the red-color stained with neutral red and non-stained diets using the diatom Coscinodiscus curvatulus. Then, the copepods were fed a mixtures of two diets, the diatom C. curvatulus, stained with neutral red, and the dinoflagellate Gymnodinium sanguineum for $14\sim60$ minutes of feeding duration. The foregut colors of females were examined using a stereo-microscope and a video monitor. The foreguts of animals fed with a high density of diatoms in mixed diets showed a dark red color, whereas those fed with a high density of dinoflagellate in mixed diets were a dark yellow. The results suggest that this species of copepod may not selectively feed either one of the diets used for this study. Their feeding activity may be more likely related to the density of available prey in their environment. Therefore, this quick and easy colorimetric approach could provide very useful information, like the pre-screening procedure before designing and conducting the time-consuming and complex feeding experiments to understand the feeding ecology of copepods.