• Korean Journal of Ichthyology
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• v.26 no.4
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• pp.303-309
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• 2014

Feeding ecology of Collichthys lucidus was determined by analysis of stomach contents of 926 specimens ranged from 3.5 to 18.5 cm in the Han River estuary. This fish actively fed on benthic crustaceans, mainly decapods, Palaemon carinicauda and Acetes chinensis, and they can be defined as the benthivorous predator. The percentage of empty stomachs was 23.8%. The vacuity index (VI) did not vary with the size classes, but showed significant monthly variations. Monthly variation of feeding activity appears to be related to the reproduction cycle of the fish, and to the temporal abundance of the prey organisms. Collichthys lucidus in Han River estuary fed on a wide array of prey items and could be considered as a non-selective predator.

• Journal of Korean Society of Environmental Engineers
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• v.35 no.12
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• pp.953-959
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• 2013

In this study, through the analysis of the growth condition and prey of the largemouth bass, we tried to understand the characteristics of the aquatic animal community depending on the composition and shape of a artificial lake. The evaluation was conducted for Ilsan lake which is one of the largest urban artificial lakes in Korea. Weight gain rate of the Zone III (eco-zone) was more rapid based on the relationship of length and weight of largemouth bass. Total 16 and 9 species of fish were found in each Zone III and Zone I, II (artificial zones), which represented significantly higher diversity of fish species in Zone III than Zone I, II. Index of relative importance(IRI) was more diverse at Zone III and when considering the hunger rate the food stress was more serious at Zone I, II. the proportion of the population of fish, Zacco platypus revealed to be the dominant species, and Squalidus gracilis majimae and Rhinogobius brunneus inhabited only Zone III naturally rich. On account of low prey species diversity of Zone I, II, the Phylum Arthropoda like Heteroptera showed relatively higher prey ratio in stomach of largemouth bass than that of Zone III. It was possible to figure out aquatic animal community characteristics indirectly through analyzing the stomach contents of largemouth bass.

• Korean Journal of Ichthyology
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• v.24 no.3
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• pp.191-200
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• 2012

Fish species composition in eelgrass bed of Punghwa-ri in Tongyeong, Korea was determined using monthly samples collected by a surf net from November 2010 to October 2011. During the study period, a total of 30 species, 5,511 individuals and 6,933.4 g of fishes were collected. The dominant fish species were Pholis nebulosa, Syngnathus schlegeli, Rudarius ercodes, Pseudoblennius cottoides, Sebastes inermis, and Aulichthys japonicus which accounted for 93.4% of total number of individuals collected. Most fishes collected in the eelgrass bed belong mainly to small fish species or juveniles of large fish species. Eelgrass shoot density reached a peak in April 2011, and then decreased to a minimum in January 2011. The seasonal variation of fish assemblage in an eelgrass bed of Punghwa-ri was correlated to the variations in the water temperature, eelgrass density and biomass, and abundances of major prey organisms.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.51 no.4
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• pp.637-643
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• 2015

The diet composition of juvenile Trachurus japonicus were studied using 195 specimens collected from 2013 (May, June, July, and September) to 2014 (May, June, and July) in the coastal waters of Geumodo, Yeosu, Korea. The size of juvenile T. japonicus ranged from 4.3 to 15.2 cm in body length (BL). Juvenile T. japonicus was carnivorous and crustaceans predators that consumes mainly consumed copepods. Its diet also included small quantities of decapods, cirripedians, nematods, chaetognathans, fishes, amphipods, cumaceans, ostracods and euphausiids. The graphical method for feeding strategy revealed that juvenile T. japonicus is an opportunistic and specialized predator on copepods, especially Corycaeus. affinis, and showed narrow niche width. Juvenile T. japonicus showed ontogenetic diet change. Small size group individuals (4.3-8.0 cm BL) mainly consumed copepods. The portion of this prey item decreased in the large size group (8.0-15.2 cm BL), and this decrease was paralleled with increased consumption of decapods.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.54 no.1
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• pp.73-79
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• 2021

The feeding habits of Chub mackerel Scomber japonicus were investigated using 329 specimens collected from coastal waters of the South Sea of Korea. S. japonicus is mainly a piscivore, consuming small fish such as Engraulis japonicus (%RI: 81.0 %). The diet of Chub mackerel also includes small quantities of thaliaceans, euphausiids, and amphipods. We calculated the trophic level as 3.92 for S. japonicus. The dietary composition of S. japonicus did not show significant differences with size, but differed with season. As the body size of S. japonicus increased, the mean weight of prey within the stomach (mW/ST) increased (One-way ANOVA, P<0.05).

• Korean Journal of Fisheries and Aquatic Sciences
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• v.54 no.6
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• pp.1052-1057
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• 2021

The diet composition of common flying squid Todarodes pacificus was studied using 1,084 specimens collected through trawl and jigging from June 2018 to June 2020 in the East Sea of Korea. The mantle length (ML) of the collected individuals ranged from 13.6 to 31.1 cm. Todarodes pacificus is a carnivore. In the study area, T. pacificus was observed feeding mainly on fish and cephalopods, in addition to small quantities of crustaceans. The calculated trophic level value for T. pacificus was 4.10. Small individuals (ML, <18.0 cm) mainly fed on cephalopods, while intermediate (ML, 18.0-23.0 cm) and large (ML, ≥23.0 cm) individuals fed mainly on fish and occasionally on cephalopods. Overall, as the body size of T. pacificus increased, the mean weight of the consumed prey increased (one-way ANOVA, P<0.05).

• Korean Journal of Fisheries and Aquatic Sciences
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• v.50 no.5
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• pp.616-620
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• 2017

The feeding habits of post-larval Yatabe blenny Parablennius yatabei (2.0-9.8 mm SL) were examined on the basis of 158 individuals collected from June to October in the coastal waters of eastern Jinhae Bay, South Korea. Based on the index of relative importance (IRI), post-larval P. yatabei fed 94.4% on copepods and 5.6% on tintinnids. The preference of post-larval P. yatabei for copepods to other prey items results from ontogenetic changes. The dietary percentage of copepods increased as fish size increased and tintinnids became less important. The feeding rate of post-larval P. yatabei was consistent at all times of day.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.48 no.5
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• pp.752-759
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• 2015

We examined the feeding habits of larval Konosirus punctatus using 165 specimens collected from May to August 2011 in the Nakdong River estuary, Korea. We found that larval K. punctatus [3.9-8.4 mm notochord length (NL)] are carnivorous, consuming mainly rotifers. Their diet also included small numbers of rhizopods, tintinnids, euglenoids, copepods, larval bivalves, dinoflagellates, diatoms, and unidentified materials. To evaluate ontogenetic changes in dietary composition, we split the larvae into three size groups: < 5 mm, 5-6 mm, and > 6 mm NL. The smallest size group frequently preyed on rhizopods. As NL increased, the number of rotifers increased relative to those of rhizopods. Larvae also showed bimodal feeding for feeding incidence, with peaks in the midafternoon and at midnight, while the mean number of prey per individual peaked at 18:00-19:00 h.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.48 no.3
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• pp.368-376
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• 2015

The Feeding habits of larval Liparis tanakae collected from the Nakdong River estuary were studied. L. tanakae [3.8-10.6 mm notochord length(NL)] was a carnivore thatconsumed mainly copepods. Its diet also included small numbers of free-living flatworms (Macrostomida), tintinnids, cladocerans, and polychaetes larvae. To evaluate ontogenetic changes in dietary composition, three size groups were designated: 3-5, 5-7, and >7 mm. Copepods were the most important prey items for all size groups. The smallest size group frequently preyed on polychaete and bivalve larvae, along with copepods. As notochord length increased, the numbers of cladocerans and Macrostomida increased relative to those of polychaete and bivalve larvae.

• Journal of the Korean Society of Marine Environment & Safety
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• v.22 no.6
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• pp.766-772
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• 2016

The composition of the diet of juvenile barbel steeds, Hemibarbus labeo was studied using 67 specimens collected in August, 2004 from the surf zone of the Nakdong river estuary. The fish examined ranged from 5.1 to 9.7 cm in standard length (SL). Hemibarbus labeo was found to be carnivorous and consumed mainly amphipods, with teleosts, polychaetes, and shrimps following. They showed size-related changes in diet. Small individuals (< 6.4 cm SL) mainly consumed amphipods. As fish size increased, the portion of amphipods consumed decreased, while a reverse trend was evident for teleosts. It was also observed that Hemibarbus labeo consumed more amphipods and polychaetes during the day, while fish served as their main prey during the night.