• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.55 no.4
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• pp.320-326
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• 2019

The diet composition of Arctoscopus japonicus was studied using 448 specimens collected in the coastal waters of East Sea, Korea. The size of the specimens ranged from 6.2-25.3 cm in total length (TL). A. japonicus were fed mainly on amphipods that constituted 76.1% in IRI. Euphausiids were the second largest prey component. The diets also include small quantities of crabs, copepods, mysids, cephalopods, monogeneans, and fishes. A. japonicus showed ontogenetic changes in feeding habits. Smaller individuals (6-10 cm, TL) fed mainly on amphipods. The proportion of amphipods decreased as body size increased, whereas the consumption of euphausiids gradually increased (10-14 cm, TL). As the body size more increased, the proportion of amphipods increased whereas euphausiids decreased (14-26 cm, TL).

• Korean Journal of Environmental Biology
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• v.20 no.4
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• pp.312-315
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• 2002

Impact of artificial illumination on zooplankton dynamics has been studied in Tongyong marine ranch during the period from August 1998 to August 1999. Monthly sampling has been carried out to collect zooplankters from both natural waters and artificially illuminated waters at night. A total of 48 taxa of zooplankton occurred during the study. Copepods showed the prosperity in species number with 21 species. Every sample from illuminated waters consisted of move than 15 species except February while less than 15 species in samples from natural waters during the winter. Benthic amphipods occurred abundantly in illuminated waters. Zooplankton abundance was revealed to be increased in illuminated waters mainly due to the gathering of amphipods (4,500 indiv. $m^{-3})$ in September and October. Twenty times of zooplankton abundance was recorded in illuminated waters when compared with that in natural ones in September due to the gathering: of amphipods and ten times by the explosion of N. scintillans in August 1999. However, no distinct difference in the abundance was observed between two waters in the winter. Zooplankton gathering with artificial illumination seemed to be effective in amphipods, while copepods were hardly affected by the artificial illumination at night.

• Ocean Science Journal
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• v.40 no.1
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• pp.17-24
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• 2005

A series of experiments were conducted to develop standard test organisms and test protocols for measuring sediment toxicity using candidate amphipods such as Mandibulophoxus mai, Monocorophium acherusicum, Haustorioides indivisus, and Haustorioides koreanus, which are indigenous to Korea. The relevant association of test species with sediment substrates was one of the important factors in sediment bioassay. The indigenous amphipods M mai and M. acherusicum were well associated with test sediments when they were exposed to various sediment substrates from sand to mud. The tolerant limits to various physico-chemical factors affecting bioassay results such as temperature, salinity and ammonia, as well as sensitivities to reference toxicant and contaminated sediments, were investigated using M. mai and M. acherusicum in the present study. These amphipods were tolerant to relatively wide ranges of salinity $(10{\sim}30\;psu)$ and ammonia (<50 ppm), and displayed relevant sensitivity to temperature as well. They are more sensitive to Cd, the reference toxicant, when compared to the standard test species used in other countries. Field-sediment toxicity tests revealed that M. mai would be more sensitive to sediment-associated pollutants than M. acherusicum, while the sensitivity of M. acherusicum was comparable to that of Leptocheirus plumulosus, which has been used as a standard test species in the United States of America. Overall results of this first attempt to develop an amphipod sediment toxicity test protocol in Korea indicated that M. mai and M. acherusicum would be applicable in the toxicity assessment of contaminated sediments, following the further evaluation encompassing various ecological and toxicological studies in addition to test method standardization.

• Korean Journal of Ichthyology
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• v.10 no.1
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• pp.24-31
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• 1998

Feeding habits of Acentrogobius pflaumii collected from the eelgrass bed in Kwangyang Bay from January 1994 to December 1994 were studied. Acentrogobius pflaumii was a carnivore which consumed mainly gammarid amphipods, polychaetes and gastropods. Its diets included minor quantities of cope pods, tanaids and crabs. It showed ontogenetic changes in feeding habits. Individuals of 1~2cm SL preyed heavily on gammarid amphipods. However, polychaetes and gastropods were selected with increasing fish size. Although gammarid amphipods, polychaetes, and gastropods were major prey organisms for all seasons, the relative proportion of these food items changed with season. Consumption of gammarid amphipods and polychaetes was relatively high in summer, and consumption of gastropods was relatively high in winter.

• Korean Journal of Ichthyology
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• v.18 no.3
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• pp.178-183
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• 2006

Diel changes in the feeding habits of Rudarius ercodes were investigated in an eelgrass bed of Jindong Bay, Korea. The main food components for R. ercodes (1.6~ 4.3 cm SL) were gammarid amphipods, eelgrass, polychaetes and urochordates. Most dietary items were inhabitants of an eelgrass bed. Diel variations in diet and feeding activity occurred. The diet of R. ercodes underwent changes from eelgrass and gammarid amphipods (omnivore) at day to mainly gammarid amphipods, polychaetes, and urochordates (carnivore) at night. Rudarius ercodes probably took detached eelgrass leaves and grazed live eelgrass during day, whereas feeding on gammarid amphipods, polychaetes, urochordates, and bivalves were facilitated by nocturnal movement and activity of these prey during night. The feeding activity of R. ercodes was also correlated with periods of high tides.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.36 no.4
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• pp.372-377
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• 2003

Feeding habits of juvenile Liparis tanakai collected from the eelgrass bed in Kwangyang Bay were studied. L. tanakai (2.0-6.0 cm SL) was a carnivore which consumed mainly amphipods (caprellids and gammarids) and caridean shrimps. Its diets also included a large amount of copepods, polychaetes and small fishes. Three distinct ontogenetic feeding groups were noted: (1) the individuals of 2.0-2.5 cm SL preyed heavily on copepods, (2) individuals of 2.5-4.0 cm SL fed mainly on amphipods. (3) individuals over 4.0 cm SL preyed mainly on caridean shrimps and small fishes. The dietary breadth of each size class showed relatively low value, and this means that juvenile L. tanakai depends on only few kinds of food organisms.

• Proceedings of the Korean Aquaculture Society Conference
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• 2005.05a
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• pp.80-81
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• 2005

To investigate the food organisms of the Acanthogobius hasta during the juveniles stage, the stomach contents of fish, captured in the intertidal zone of Chungchong- nam-do Sochon-gun Su-myon Dodun-ri (Fig. 1) between on early June from end of May 2003, were observed. Total length of the juveniles of A. hasta was 5.5 mm ${\sim}$ 8.9 mm size, and the participation rate of feeding was 69.6%. Main food organisms were such as copepods, decapods, polychaete larvae, amphipods and these occupied more than dry weight 3.9%. Copepods among them dominated the most quantitys by average 62.7%, and next, food organisms appeared much by order of decapods, polychaete larvae and amphipods etc.. Therefore, most important food organisms of juvenile stage of A. hasta were copepods, decapods, polychaete larvae, amphipods etc.

• Proceedings of the Korean Aquaculture Society Conference
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• 2005.05a
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• pp.82-83
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• 2005

To investigate the food organisms of the Chaenogobius mororanus during the juveniles stage, the stomach contents of fish, captured in the intertidal zone of Chungchong- nam-do Sochon-gun Su-myon Dodun-ri (Fig. 1) between on early June from end of May 2003, were observed. Total length of the juveniles of C. mororanus was 5.0 mm ${\sim}$ 8.4 mm size, and the participation rate of feeding was 71.4%. Main food organisms were such as copepods, decapods, polychaete larvae, amphipods and these occupied more than dry weight 3.9%. Copepods among them dominated the most quantitys by average 62.0%, and next, food organisms appeared much by order of decapods, polychaete larvae and amphipods etc.. Therefore, most important food organisms of juvenile stage of C. mororanus were copepods, decapods, polychaete larvae, amphipods etc.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.46 no.4
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• pp.358-367
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• 2010

Feeding habits of Acentrogobius pellidebilis collected from in an eelgrass(Zostera marina) bed from January to December 2006 were studied. A. pellidebilis ranged form 1.6 to 6.9 cm in standard length were determined. A. pellidebilis was a carnivore which consumed mainly copepods, polychaetes, and amphipods. Its diets included small quantities of isopods, seaweeds, nematods, and gastropods. It showed ontogenetic changes in feeding habits. Smaller individuals (<2.0cm SL) fed mainly on copepods. While the consumption of copepods decreased with increasing fish size, the consumption of polychaetes and amphipods were increased. Dietary breadth index was varied with fish size.

• Journal of the Korean Society for Marine Environment & Energy
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• v.8 no.1
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• pp.9-16
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• 2005

A series of experiments was conducted to evaluate the effects of temperature on the survival, growth and sensitivity of the benthic amphipods, Mandibuluphoxus mai and Monocnrophium acherusicum, which have been recently developed as new sediment toxicity testing species in Korea. The biological performance for each amphipod species was determined by the survival and growth rates at different water temperatures. The influence of temperature on the sensitivity to reference toxicant, Cd, was determined by the comparison of survival rates of amphipods exposed to control and Cd-spiked seawater at different temperatures. Temperature significantly influenced on the survival, growth and Cd sensitivity of both amphipods. Tolerable ranges of temperature for the >80％ individuals of both M. mai and M. acherusicum with sediment substrates were mostly overlapped (13 to 22℃). The daily growth rates of M. mai and M. acherkisicum increased proportionally with temperature up to 20℃ and 25℃. respectively. Similarly, the sensitivities of M. mai and M. acheyusicum to Cd increased with temperature up to 20℃ and 15℃, respectively. Overall results showed that temperature is a substantially important factor potentially influencing the results of lethal and sublethal bioassays using the amphipods. Therefore, defining the adequate ranges of experimental temperature for the toxicity testing species is the pre-requisite for the development of standardized bioassay protocols.