• Title/Summary/Keyword: 먹이

Search Result 2,080, Processing Time 0.031 seconds

요각류 Calanus helgolandicus의 번식력에 미치는 단일, 혼합 먹이, 알 포식의 영향

  • ;Serge Poulet
    • Proceedings of the Korean Society of Fisheries Technology Conference
    • /
    • 2000.05a
    • /
    • pp.359-360
    • /
    • 2000
  • 해양 생태계에서 규조류는 요각류의 생산력에 필요한 중요한 먹이인 것으로 인식되고 있다. 그러나, 많은 실험실 연구에서 규조류가 요각류의 번식력을 억제할 수 있음을 보여주고 있다 (Ban et al., 1997; Poulet et at., 1994, 1995; Chaudron et al., 1996). 요각류 성체 암컷이 규조류를 섭식할 경우 요각류의 알 생산력이나 알 부화율이 낮아질 수 있으며, 이러한 저해 작용은 규조류가 아닌 다른 먹이 (와편모조류)로 대체하였을 경우, 정상적으로 회복될 수 있으며, 이러한 저해 작용은 먹이로 제공된 규조류의 밀도가 높을수록 더 강하게 나타나고 있었다. 이러한 증거들로 인하여 실제 해양에서 요각류의 번식력과 규조류 사이의 연결성에 대하여 의문이 제기되고 있다. (중략)

  • PDF

The multi agent control heuristic using direction vector (방향 벡터를 이용한 다중에이전트 휴리스틱)

  • Kim Hyun;Lee SeungGwan;Chung TaeChoong
    • Proceedings of the Korea Information Processing Society Conference
    • /
    • 2004.11a
    • /
    • pp.525-528
    • /
    • 2004
  • 먹이추적문제(prey pursuit problem)는 가상 격자로 이루어진 공간 내에 다중의 에이전트를 이용하여 먹이를 포획하는 것이다. 에이전트들은 먹이를 포획하기 위해 $30{\times}30$으로 이루어진 격자공간 (gride)안에서 기존 제안된 지역 제어, 분산 제어, 강화학습을 이용한 분산 제어 전략들을 적용하여 먹이를 포획하는 전략을 구현하였다. 제한된 격자 공간은 현실세계를 표현하기에는 너무도 역부족이어서 본 논문에서는 제한된 격자공간이 아닌 현실 세계와 흡사한 무한 공간 환경을 표현하고자 하였다. 표현된 환경의 모델은 순환구조(circular)형 격자 공간이라는 새로운 실험 공간이며, 새로운 공간에 맞는 전략은 에이전트와 먹이와의 추적 관계를 방향 벡터를 고려한 모델로 구현하였다. 기존 실험과는 차별화 된 환경에서 에이전트들은 휴리스틱을 통한 학습을 할 수 있다는 가정과 먹이의 효율적 포획, 충돌문제 해결이라는 결과를 얻었다.

  • PDF

모유의 의학적 가치와 모유은행의 필요성

  • 이근
    • 가정의 벗
    • /
    • v.37 no.8 s.432
    • /
    • pp.6-7
    • /
    • 2004
  • 모유은행이란 모유를 꼭 먹어야 하는 아기들이 자기 엄마의 젖을 먹을 수 없는 상황에서 다른 엄마들의 젖을 모아 비축했다가 필요시에 먹이는 제도를 말한다. 우리나라에서도 의학적으로 모유은행의 필요성을 인정하고 모유은행이 제도화 될 수 있도록 노력해야 한다.

  • PDF

Diet Partitioning between Co-occurring Amblychaeturichthys hexanema and Amblychaeturichthys sciistius in the Southeastern Korean Waters (동해 남부 연안에 출현하는 도화망둑 (Amblychaeturichthys hexanema)과 수염문절(Amblychaeturichthys sciistius)의 먹이 분할)

  • Huh, Sung-Hoi;Park, Joo Myun;Baeck, Gun Wook
    • Korean Journal of Ichthyology
    • /
    • v.28 no.2
    • /
    • pp.79-86
    • /
    • 2016
  • Stomach contents of Amblychaeturichthys hexanema and A. sciistius (Perciformes: Gobiidae) from southeastern waters off Korea were analyzed to determine dietary habits and the presence of any inter- and intra-specific partitioning of food resources. These two species were bottom-feeding carnivores that consumed mainly benthic crustaceans, and other demersal invertebrates and planktonic organisms were also important in their diets. Non-metric multidimensional scaling (nMDS) ordination and multivariate analyses based on gravimetric contributions of the different prey taxa to stomach contents revealed significant inter-specific dietary differences; i.e. partitioning of food resources between the two species. Size-related changes, however, were not significant for their diets. Differences in the types and range of prey ingested by the two species could often be related to differences in the feeding behaviors. Our results of stomach contents analyses provide clear evidence of niche segregation between co-occurring A. hexanema and A. sciistius in southeastern Korean waters, which would reduce the likelihood of inter-specific competition for food resources.

Dietary Values of Benthic Diatoms for Growth Recovery of the Retarded Spat of Abalone, Haliotis discus hannai Ino (성장이 늦은 소형 참전복 치패의 성장회복을 위한 부착성 규조류의 먹이효율)

  • 한형균;허성범
    • Journal of Aquaculture
    • /
    • v.13 no.2
    • /
    • pp.163-168
    • /
    • 2000
  • Dietary value of eight species of benthic diatoms, considered as essential live food for larvae and spat of abalone, was assessed on the retarded spat (ca 4.4 m shell length). Survival of the spat, fed on Caloneis schroderi, Phaeodactylum tricornutum and Raphoneis sp. was over 93 % and significantly higher than that of others; spat fed on C かwがwi gained the highest daily growth of 112.6 mm, which was two times faster than that fed on Undaria pinnatifida Spat fed on natural or cultured diatoms of C. schroderi grew at rates, that were not significantly different. C. schroderi is recommended to restore the retarded growth of abalone spat.

  • PDF

Food Web Models in Aquatic Ecosystems: Review (수생태계 먹이망 모델 고찰)

  • Young-Seuk Park;Kyung Ah Koo
    • Korean Journal of Ecology and Environment
    • /
    • v.55 no.4
    • /
    • pp.259-273
    • /
    • 2022
  • Interactions between species in a community are very complex, and they are visualized and analyzed through a food web in simple way. Food web is a network of species connected by trophic links showing energy flow from prey to predator. Various models were developed to characterize the food web in ecosystems. In this study, we classified food web models to static models such as Ecopath and dynamic models such as AQUATOX. We presented characteristics of several different types of food web models in each category, and reviewed their applications used in aquatic ecosystems. Finally, we presented issues to be considered to develop food web models.

A Study on Food Resource and Utilization of Artificial Nest of Wild-birds in Urban Woodland (도시공원내 야생조류의 먹이자원 및 인공새집 이용에 관한 연구)

  • 김종갑;이성규;민희규;민기철
    • The Korean Journal of Ecology
    • /
    • v.25 no.5
    • /
    • pp.275-282
    • /
    • 2002
  • Preference of food plants of wild birds was shown in the order of Pinus densiflora, Celtis sinensis, Celastrus orbiculatus, Rosa multiflora, Taxus cuspidata, and Euonymus japonica, etc. The wild birds preferred the animal food(92.2%) rather than the vegetable food(32.7%) in breeding season(May through June), but preferred both animal and vegetable foods in non-breeding season(November through December). The rates utilzing artficial nest were 77.5%, 50.3%, 44.1% and 42.2% in Nosan, Sanho, Chinju-castle and Bibong parks, respectively. The wild birds used more the 3cm hole than 5cm hole.

Increased Attractiveness of the Aggregation Pheromone Trap of Bean Bug, Riptortus clavatus (먹이 첨가에 의한 톱다리개미허리노린재 집합페로몬 트랩의 유인력 증진)

  • Huh Wan;Park Chung-Gyoo
    • Korean journal of applied entomology
    • /
    • v.45 no.1 s.142
    • /
    • pp.87-90
    • /
    • 2006
  • The effect of food source in aggregation pheromone trap of bean bug, Riptortus clavatus, was evaluated in terms of the trap attractiveness using water-ran and cylinder-type traps. Water-pan trap baited with pheromone + food (dried soybean + dried peanut + water) attracted significantly more number of females and males than those with pheromone or control trap. Although cylinder-type trap baited with pheromone + food did not show significantly higher attractiveness, it attracted more adults and nymphs than the pheromone and control traps. Further research on the effect of trap types on attractiveness is needed.

Feeding Habit of Gobiobotia brevibarba (Cyprinidae) from the Hongcheon River, Korea (홍천강에 서식하는 돌상어 (Gobiobotia brevibarba)의 식성)

  • Choi, Jae-Suk;Kwon, Oh-Kil;Park, Jung-Ho;Byeon, Hwa-Kun
    • Korean Journal of Ichthyology
    • /
    • v.13 no.4
    • /
    • pp.230-236
    • /
    • 2001
  • Feeding habits of Gobiobotia brevibarba were investigated at Hongcheon River of Bangokri, Seomyon, Hongcheongun, Kangwondo from January to December, 2000. G. brevibarba was a carnivore and consumed mainly Ephemeroptera, Tricoptera and Diptera. Small quantities of Plecoptera and Coleoptera were included as a minor food items. The species showed ontogenetic changes in feeding habits. Individuals of small size (21~50 mm SL) fed mainly on small prey organisms such as Diptera and Ephemeroptera. However, larger Tricoptera were heavily selected with increasing fish size. The relative proportion of these food items changed with season. The prey selection indices for Ephemeroptera were positively selected in spring, summer and autumn, and negatively selected in winter, Diptera were positively selected in March, October and November.

  • PDF

Population growth and vermicomposting rate of earthworm (Eisenia fetida) according to amounts of feed supply and initial densities of earthworm populations (줄지렁이(Eisenia fetida) 입식 밀도 및 먹이 급이량에 따른 지렁이 개체군 생장 및 먹이 섭식효율)

  • Bae, Yoon-Hwan;Park, Kwang-Il
    • Journal of the Korea Organic Resources Recycling Association
    • /
    • v.14 no.4
    • /
    • pp.104-112
    • /
    • 2006
  • Population growths of earthworm were investigated when the earthworm populations with different levels of initial densities per unit area were fed with cow dung mixed with paper mill sludge. The tested levels of earthworm densities were as follows; $1kg/m^2$, $2kg/m^2$, $3kg/m^2$, $5kg/m^2$. There were no significant differences in population growth rates 60 and 90 days after feed supply among the tested densities of earthworm. Therefore, it was suggested that initial densities of earthworm populations per unit area higher than $3kg/m^2$ should not be favorable because of the cost for purchasing earthworm. Vermicomposting rates of earthworm on feed were also investigated when different amounts of feed were supplied repeatedly to unit area of nursery bed with $5kg/m^2$ of initial densities earthworm populations. The tested amounts of feed at each supplying time were as follows; $16kg/m^2$, $24kg/m^2$, $32kg/m^2$, $40kg/m^2$. The more the amount of feed at each supplying time, the higher vermicomposting rate and population growth rate. Therefore, it should be more favorable for earthworm breeders to supply more than $40kg/m^2$ of feed at each supplying time, because it would reduce time and labor cost.

  • PDF