• Fisheries and Aquatic Sciences
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• 제26권8호
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• pp.482-490
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• 2023

Food and feeding habits of Labeobarbus intermedius were studied from the newly constructed Ribb Reservoir, Ethiopia during the dry (December-March) season and wet season (June-August) of 2021. The objective of the study was to determine the diet composition, seasonal variation, and ontogenetic dietary shift in the diets of the dominant cyprinid fish in Ribb Reservoir. In this study, frequency of occurrence and volumetric analysis methods were used to present the results. From a total of 203 fish samples, 132 (65%) guts contained food items. Macrophytes (29.4%), phytoplankton (27.2%), detritus (14.8%), and insects (13.6%) were the major food items in the diets volumetrically. During the dry season, L. intermedius was mainly dependent on phytoplankton (58.2%), insects (15.2%), and zooplankton (13.7%) volumetrically. Whereas, macrophytes (50.3%) and detritus (23.3%) were the dominant food items in the wet season. The frequency occurrence and volumetric contribution of the diets of L. intermedius varied significantly (χ² test, p < 0.05) between seasons. Schoener's diet overlap index revealed a slight ontogenetic dietary shift in the diets of L. intermedius. While insects, nematodes, and zooplankton were the main diets of small-sized L. intermedius, macrophytes and detritus were ingested by large-sized L. intermedius. Generally, L. intermedius fed both plant and animal-origin food items and is considered an omnivorous feeder in Ribb Reservoir.

• Fisheries and Aquatic Sciences
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• 제26권3호
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• pp.169-180
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• 2023

Oreochromis niloticus is the most ecologically and economically important fish in tropical and sub-tropical aquatic systems. Recently, due to sever anthropogenic stressors, hydrological variations and infestations of invasive alien species in Ethiopian water bodies, fish community structure and ecosystem of Lake Tana is changing alarmingly. So far, there is paucity of information on the morphometric relations and diet composition of O. niloticus in Lake Tana, gulf of Gorgora. A total of 309 fish samples were collected and their total length (TL), standard length (SL) and total weight (TW) were measured to determine morphometric relations; and gut contents were examined to identify most important food item in the diet of the fish. Results indicated that, the relation between TL and SL was significant (p < 0.001) and linear (SL = 0.942TL-2.41) while the relation between TL and TW was curvilinear (TW = 0.014 TL^2.8) indicating allometric growth. Among the total guts scrutinized, 53 (17.3%) of them were empty and the remaining 256 (82.7%) were non-empty. Phytoplankton constituted the largest bulk and occurred in 77% of the guts examined and volumetrically accounted 44.3%. Detritus and zooplankton had an intermediate importance by occurring 60.2% and 63.3% of all guts scrutinized and constituted about 25.6% and 15.5% of the total volume respectively. Contributions of macrophytes, insects, nematodes and unidentified food items were relatively low in their importance. Ontogenetic dietary shift was observed in the diet indicating an omnivorous feeding habit of the adult fish.

• 수산해양기술연구
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• 제51권2호
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• pp.265-271
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• 2015

The feeding habits of Okamejei kenojei were studied using 242 specimens collected from October 2010 to September 2011 in the coastal waters of Gadeok-do, Korea. O. kenojei was carnivorous feeder that consumed mainly shrimps, crabs, and fishes. Its diet also included small quantities of stomatods, cephalopods, amphipods. The size of O. kenojei ranged from 10.4 to 47.4 cm in total length (TL). O. kenojei showed ontogenetic dietary shift. <15.0, 15.0-19.9 cm size classes fed mainly on shrimps and amphipods. 20.0-24.9 cm size class fed mainly shrimps and crabs. Thereafter, shrimps and crabs were decreased with ontogenesis while fishes and cephalopods were increased. Increasing size, the mN/ST were constantly decreased, but mW/ST were constantly increased.

• 한국어류학회지
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• 제27권1호
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• pp.33-38
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• 2015

주둥치의 위내용물 분석에 이용된 개체는 총 350개체로 가덕도 주변해역에서 2010년 10월부터 2011년 9월까지 매월 채집하였다. 주둥치의 체장범위는 3.0~9.8 cm를 보였다. 주둥치는 주로 요각류와 게류 유생, 새우류 유생, 갯지렁이류 등을 섭식하는 육식성 어류로 확인되었다. 그 외에 난바다곤쟁이류, 단각류, 이매패류 유생, 복족류 유생 등도 발견되었지만, 그 양은 많지 않았다. 주둥치는 성장함에 따라 주요 먹이생물을 전환하였는데 3~5 cm 사이의 개체들은 요각류를, 5~7 cm 사이의 개체들은 게류 유생과 새우류 유생을, 8~10 cm의 개체들은 갯지렁이류를 주로 섭식하였다. 체장이 증가함에 따라 먹이생물의 무게는 유의하게 증가하였다.

• 한국수산과학회지
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• 제47권2호
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• pp.160-167
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• 2014

The feeding habits of Tridentiger bifasciatus were studied using 733 individuals collected in the tidal creek at Sangnae-ri, Suncheon, Korea, using a push net, monthly, from April 2011 to March 2012. The standard length (SL) of the specimens ranged from 1.5 to 8.2 cm. The stomach content analysis indicated that T. bifasciatus consumed mainly amphipods, such as Corophium sp., while copepods, polychaetes, and shrimps were other important prey species. In addition T. bifasciatus ate small quantities of crab larvae, fish, gastropod larvae, and insects. T. bifasciatus is a generalist that feeds on various zoobenthos, including fish. T. bifasciatus underwent an ontogenetic dietary shift. Smaller individuals (1-2 cm SL) fed mainly on amphipods. The proportion of amphipods decreased as body size increased, whereas the consumption of polychaetes increased gradually. The seasonal variation in the diet composition of T. bifasciatus was significant. Insects were common prey during summer, while the amounts of other prey, including polychaetes, were similar during spring, autumn, and winter.

• 한국어류학회지
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• 제34권3호
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• pp.172-178
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• 2022

눈볼대는 중, 대형 외끌이 어업을 비롯한 기선저인망어업에 어획되는 대표적인 어종으로 생산금액 증가와 어획량, 수산식품 선호도를 보았을 때, 상업적인 가치는 더욱 높아질 것으로 판단된다. 해양생태계가 변화하고 있지만, 눈볼대 섭식생태에 관한 선행연구는 2004년부터 2008년까지 채집된 개체들을 대상으로 수행이 되어 추가 연구수행이 필요하다. 남해에서 저층트롤어업으로 채집된 눈볼대 701개체의 전장범위는 3.3~33.1 cm로 나타났으며, 공복률은 78.3%였다. 눈볼대의 주먹이생물은 어류였으며, 어류 중에서도 멸치가 가장 우점하였다. 눈볼대는 성장함에 따라 단각류, 새우류와 같은 갑각류에서 어류로 먹이생물의 전환이 이루어지는 것으로 관찰되었다. 먹이 섭식 특성의 경우, 개체당 먹이생물의 평균 중량 (mW/ST)은 성장함에 따라 지속적으로 증가했고, 평균 먹이생물의 개체수(mN/ST)는 감소하다가 증가하는 것으로 나타났다. 영양단계의 범위는 3.31±0.52~3.79±0.70으로 나타났으며, 평균 영양단계는 3.62±0.64로 나타났다.