• Title/Summary/Keyword: Feeding Habits

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Feeding habits of the Pacific bluefin tuna, Thunnus orientalis in the southern sea of Korea (한국 남해안에 출현하는 태평양참다랑어 Pacific bluefin tuna, Thunnus orientalis의 식성)

  • YOON, Sang Chul;YOO, Joon Taek;LEE, Sung Il;KIM, Zang Geun;CHOI, Kwang Ho
    • Journal of the Korean Society of Fisheries and Ocean Technology
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    • v.51 no.4
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    • pp.553-560
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    • 2015
  • The feeding habits of the Pacific bluefin tuna, Thunnus orientalis were examined based on the stomach contents of 330 specimens caught by offshore large purse seine fishery in the southern sea of Korea, 2011. The size of Pacific bluefin tuna used in this study ranged from 34.1 to 67.3 cm in fork length (FL). The percentage of empty stomachs was 41.8%. The main prey items were Pisces and Cephalopoda based on percentage IRI (index of relative importance). The main fish preys were Trachurus japonicus, Bregmaceros japonicus, Engraulis japonicus, and Cephalopoda were Todarodes pacificus, Loligo edulis, Watasenia scintillans. T. orientalis showed ontogenetic change in diet composition. Although Pisces dominated the diet of all length classes the portion of Cephalopoda was relatively higher in size between 40 and 50 cm other than length classes. In terms of seasonal variation in feeding habits, Pisces was the main prey group in all seasons, but Cephalopoda was also frequently consumed during spring and autumn based on %IRI.

Feeding Habits of the Blackthroat Seaperch Doederleinia berycoides in the Southern Sea of Korea (남해안에 출현하는 눈볼대 (Doederleinia berycoides)의 식성)

  • Huh, Sung-Hoi;Oh, Hyun-Soo;Park, Joo-Myun;Baeck, Gun-Wook
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.44 no.3
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    • pp.284-289
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    • 2011
  • The feeding habits of the blackthroat seaperch Doederleinia berycoides were studied using 650 specimens collected in the Southern Sea of Korea, from January to December, 2005. The size (standard length, SL) of the specimens ranged from 6.3 to 35.2 cm. D. berycoides is a piscivore that consumes mainly teleosts such as Engraulis japonicus, Acropoma japonicum, and Myctophum nitidulum. Of the fish species Engraulis japonicus was the preferred prey. D. berycoides also eats small quantities of shrimps, amphipods, euphausiids, mysids, and crabs. D. berycoides showed ontogenetic changes in its feeding habits. Smaller individuals (5-10 cm SL) fed mainly on shrimp. The proportion of shrimp decreased with increasing fish size, and this decrease paralleled the increased consumption of fish. Fish accounted for almost all of the stomach contents of individuals larger than 15 cm SL. Cluster analysis based on the percentage dry weight (%DW) identified two size groups: group A (<15 cm SL) consumed primarily shrimp and fish; and group B (15< cm SL) preyed exclusively on fish. There was little seasonal change in the diet of D. berycoides, but shrimp constituted 41.8% of the summer diet in %W.

Feeding Habits of the Pacific Cod Gadus macrocephalus in the Coastal Waters off Jumunjin, Gangwondo of Korea (강원도 주문진 해역에 출현하는 대구(Gadus macrocephalus)의 식성)

  • Yoon, Sang-Chul;Yang, Jae-Hyeong;Park, Jeong-Ho;Choi, Young-Min;Park, Jong-Hwa;Lee, Dong-Woo
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.45 no.4
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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.

Feeding habits of Acanthogobius flavimanus in the eelgrass (Zostera marina) bed in Kwangyang Bay (광양만 잘피밭에 서식하는 문절망둑 (Acanthogobius flavimanus)의 식성)

  • HUH Sung-Hoi;KWAK Seok Nam
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.32 no.1
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    • pp.10-17
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    • 1999
  • Feeding Habits of Acanthogobius flavimanus collected from the eelgrass bed in Kwangyang Bay from January to December 1994 were studied. A. flavimanus was a carnivore which consumed mainly polychaetes, crabs, shrimps, gammarid amphipods and fishes. Its diets included small quantities of ophiuroids, gastropods, bivalves, caprellid amphipods, isopods and tanaids. It showed ontogenetic changes in feeding habits. Small individuals fed mainly on polychaetes and amphipods. While the consumption of polychaetes and amphipods decreased with increasing fish sin, the consumption of shrimps, crabs and fishes increased. A. flavimanus fed diverse prey organisms in adult stage. The relative proportion of the major prey items changed with season. Although the consumption of polychaetes, shrimps and gammarid amphipods was relatively high in spring and autumn, A. flavimanus fed various prey organisms in nearly equal proportions in the other seasons.

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Feeding habits of white croaker, Pennahia argentata in the coastal waters off Sejon island, Korea (한국 남해안 세존도 주변 해역에 출현하는 보구치 (Pennahia argentata)의 식성)

  • Koh, Eun-Hye;An, Young-Su;Baeck, Gun-Wook;Jang, Choong-Sik
    • Journal of the Korean Society of Fisheries and Ocean Technology
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    • v.50 no.2
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    • pp.139-146
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    • 2014
  • Feeding habits of white croacker, Pennahia argentata, were analyzed by using the stomach contents of 153 specimens caught by bottom trawl from May 2011 to March 2012 in the Sejon island, Korea. To know feeding habits of the white croacker, P. argentata, a species composition and it's fluctuation were analyzed based on growth. White croacker, P. argentata caught in the area composes 15 species. The most species in an number of the prey was Macrura which was occupied at 66.4% from whole prey, the second most species was Pisces which was occupied at 20.3%. The most species in an wet-weight of the prey was Pisces which was 49.3% out of the whole specimens. The second most species was Macrura which was 43.3%. The frequency occurrence of the prey was Macrura which was 68.6%, the next one was Pisces which was 28.8%. The highest Index of Relative Importance (IRI) of the prey was Macrura which was 78.2%, the next one was Pisces which was 28.8%. A number of the prey per specimen of small, middle and large class were 1.3, 1.5, 1.7, respectively. A wet weight of the prey per specimen of small, middle and large class were 0.2, 0.6, 0.2 g, respectively.

Feeding Habits of Conger myriaster in the Eelgrass (Zostera marina) Bed in Kwangyang Bay (광양만 잘피밭에 서식하는 붕장어 (Conger myriaster)의 식성)

  • HUH Sung-Hoi;KWAK Seok Nam
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.31 no.5
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    • pp.665-672
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    • 1998
  • Feeding habits of Conger myiaster collected from the eelgrass bed in Kwangyang Bay from January 1994 to December 1994 were studied. C. myiaster was a carnivore which consumed mainly fishes, shrimps and crabs. Its diets included small quantities of amphipods, gastropods, cephalopods, polychaetes, mysids, cumaceans and isopods. It showed ontogenetic changes in feeding habits. Small indinviduals preyed on shrimps, fishes, crabs, and gammarid amphipods in nearly equal proportions. While the portion of the stomach contents attributable to shrimps and gammarid amphipods decreased with increasing fish size, consumption of fishes increased progressively. C. myiaster showed very constant prey selection regardless of prey availability-Especially fishes were heavily selected by this species throughout the year, although availability of fishes was lower than any other prey organisms in the eelgrass bed.

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Feeding habits of longchin goby, Chaenogobius annularis in the tidepools at the intertidal zone of Tongyeong, Korea (통영 연안 조간대의 조수웅덩이에 출현하는 점망둑 (Chaenogobius annularis)의 식성)

  • Cho, Gab Ja;Kim, Hyeon Ji;Park, Jong Hyeok;Choi, Hee Chan;Baeck, Gun Wook
    • Korean Journal of Ichthyology
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    • v.28 no.4
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    • pp.267-272
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    • 2016
  • The feeding habits of Chaenogobius annularis were studied based on gut contents analysis of 315 individuals, collected from September 2014 to August 2015 in the tidepools at the intertidal zone of Tongyeong, Korea. The size of C. annularis ranged from 17.0 to 54.0 mm in standard length (SL). C. annularis mainly consumed copepods (especially Tigriopus japonicus). Its diets included seaweeds, cirripeds, mysids and amphipods. C. annularis showed ontogenetic changes in feeding habits. Small individuals fed mainly on copepods. As body size increased, the portion of seaweed increased, whereas the consumption of copepods decreased.

Feeding Habits of Released Black Rockfish, Sebastes inermis, in Coastal Waters off Jam Island, Jinhae Bay, Korea (진해만 잠도 주변해역에서 서식하는 방류산 볼락 (Sebastes inermis)의 식성)

  • Kim, Gwang-Soo;Son, Min-Ho;Kwak, Seok-Nam;Park, Joo-Myun;Huh, Sung-Hoi
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.42 no.1
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    • pp.73-77
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    • 2009
  • Feeding habits of released Sebastes inermis obtained in daily and monthly collections from August 2007 to December 2007 in coastal waters off Jam Island in Jinhae Bay, Korea were assessed. A total 151 individuals of S. inermis (6.3-9.7 cm TL) were recaptured during the study period. Initial food intake of released S. inermis occurred within three days of released. Stomach content index increased with time, however, the percentage of stomachs devoid of contents decreased. Sebastes inermis mainly consumed gammarid and caprellid amphipods, gastropods and mysids. Diet also included small quantities of bivalves, shrimps, copepods and ostracods. Amphipods were mainly consumed at all size groups and consumption of gastropods, bivalves and shrimps increased with increasing fish size.

Seasonal Variation and Feeding Habits of Amphipods Inhabiting Zostera marina Beds in Gwangyang Bay, Korea (광양만 잘피밭에 서식하는 단각류의 계절변동과 식성)

  • JEONG Seung Jin;YU Ok Hwan;SUH Hae-Lip
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.37 no.2
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    • pp.122-128
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    • 2004
  • On the basis of monthly samples, we investigated the seasonal variation and feeding habits of amphipods inhabiting Zostera marina beds in Gwangyang Bay. Dominant species $(>1\%$ of the total number of amphipods) consist of 5 gammarids (Gammaropsis japonicus, Jassa slatteryi, Pontogenia rostrata, Atylus collingi and Ceinina japonica) and 1 caprellid (Caprella tsugarensis). Mean densities of amphipods varied from the highest of $63,148\;ind.\;m^{-2}$ in-May to the lowest of $1,247\;ind.\;m^{-2}$ in September. G. japonicus and J. slatteryi dominated in summer whereas C. japonica in autumn and winter. C. japonica was found to be a carnivorous feeder consuming mainly harpacticoid copepods and unidentified crustaceans, whereas G. japonicus, J. slatteryi, and C. tsugarensis consumed both phytoplankton and detritus. Seasonal densities of amphipods were significantly related with the shoot standing crop of the eelgrass and its epiphyte. Also densities of amphipods displayed significant difference in related with the shoot density of the eelgrass among sampling stations. These results suggest that the biological interactions between the eelgrass and amphipods as well as between the carnivorous and the herbivorous amphipods may be important in the seasonal variation of amphipods inhabiting Z. marine beds.

Feeding Habits of Dolphinfish Coryphaena hippurus in the South Sea of Korea (한국 남해에 출현하는 만새기(Coryphaena hippurus)의 식성)

  • Jeong, Jae Mook;Choi, Junghwa;Im, Yang-Jae;Kim, Jung Nyun
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.50 no.5
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    • pp.541-546
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    • 2017
  • Feeding habits of dolphinfish Coryphaena hippurus, were analyzed. Fish samples were collected by using a purse seine, fishing and set net in the southern sea of Korea from January to December 2015. The size of C. hippurus ranged from 23.8 to 127.4 cm in fork length. The species with the highest percent index of relative importance (%IRI; the most important prey taxa) in the diets of C. hippurus were teleosts and cephalopod, including Engraulis japonicus, Thamnaconus modestus and Trachurus japonicus, Loligo edulis was the most frequently consumed cephalopods. Coryphaena hippurus also ate small amounts of amphipods and carid shrimp. The dietary compositions of C. hippurus was not significantly different among size classes or seasons (ANOSIM, P>0.05). As body size of C. hippurus increased the mean number of prey per stomach (mN/ST) tended to decrease, but the opposite trend was evident for mean weight of prey per stomach (mW/ST). The mN/ST and mW/ST also significantly varied with season (one-way ANOVA, P<0.05).