• Korean Journal of Fisheries and Aquatic Sciences
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• v.34 no.6
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• pp.594-599
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• 2001

In a sandy shore surf zone of Dolsan Island, diel, tidal and seasonal effects on abundance of Acartia omorii were investigated at three sites, the bottom and surface of 1 m depth and water's edge using a sledge-net. Of these sites, the abundance of A. omorii was the highest in the bottom. Seasonal abundance data showed that A. omorii was more abundant in winter than other seasons. During the study period, the abundance of A. omorii was always higher during ebb tide than flood, The distribution patterns of A. omorii were more influenced by tide than diel change, Strong current during spring tide possiblely affected the diel migration pattern, In winter A. omorii showed a diel vortical migration in neap tide, whereas it showed a reverse vortical diel migration in spring tide. Distribution centers were located at a layer of $50\~100\;cm$ below mean sea level (MSL) during neap tide, and then it moved slightly upward during spring tide.

• Korean Journal of Ichthyology
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• v.23 no.2
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• pp.163-167
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• 2011

The feeding habits of Coilia nasus were studied using 107 specimens collected from January to December 2005 in the coastal waters off Gori, Korea. The size of C. nasus ranged from 8.4 to 29.5 cm in standard length (SL). C. nasus was a carnivore that mainly consumed shrimps and copepods. Its diet also included small quantities of amphipods, euphausiids and chaetognaths. The feeding strategy graphical method reveled than C. nasus was specialized feeder and showed narrow niche width. Both small and large size class of C. nasus mainly consumed shrimps and copepods, and did not showed significant size-related changes in feeding habits. However, the mean number and weight of preys per stomach was higher than large size class than small size class.

• 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.

• Animal Systematics, Evolution and Diversity
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• v.19 no.1
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• pp.57-93
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• 2003

Twelve species in five genera of parasitic copepods are recorded from seventeen species of freshwater fishes of Korea. They are Ergasilus coniformis n. sp., Ergasilus ventriosus n. sp., E. briani Markewitsch, E. peregrinus Heller, Neoergasilus joponicus (Harada) N. lonsispinosus Yin, N. inflatus Yin, N. bullatus n. sp., N. angustus n. sp., Sinergasilus undulatus (Markewitsch), Lernaea cyprinacea L., and Lamproglena chinensis $Y{\"{u}}.$ As the most prevalent parasitic copepod, Neoergasilus japonicus is found to parasitize as many as ten species of freshwater fishes in Korea. The fish Zacco platypus, from which seven species of parasitic copepods are discovered, turned out to be the most preferred host of the parasitic copepods in this country. Full descriptions are given of the new species and new records of Korea. Lamproglena chinensis, an incompletely known species, is also redescribed.ibed.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.26 no.3
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• pp.258-265
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• 1993

Monthly changes in the occurrence and infection levels of a parasitic copepod Acanthochondria yui(Poecilostomatoida, Chondracanthidae) on a gobiid fish Acanthogobius flavimanus were studied for a year from April 1990 to March 1991. This parasite was not found on the fish for four months from September to December. Prevalence of the parasite increased from $2.9\%$ in January to $88.9\%$ in June. Relative density and mean intensity also increased from January to June. Prevalence of A. yui increased with host size. A. flavimanus samples were never found carrying A. yui larvae of three copepodid stages(CI to CIII), although a few CIV and CV larvae were identified from April and May samples. This indicates that A. flavimanus was not the sole host of A. yui. Adult females and copepodites of A. yui were usually found in the gill arch($74.8\%$) and gill filament($80.6\%$), respectively. This suggests that copepodites select the gill filament as the most suitable place on their host A. flavimanus, and the adult females move toward the gill arch.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.55 no.3
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• pp.374-378
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• 2022

The feeding habits of the Glowbelly Acropoma japonicum were examined based on 849 specimens collected from the coastal waters of the South Sea of Korea. The total length (TL) of these specimens ranged from 2.6 to 13.0 cm. A. japonicum fed majorly on Euphausia pacifica (Euphausiacea, % index of relative importance; IRI, 51.9). However with growth, its diet shifted from copepoda to euphausiacea. Overall, as the body size of A. japonicum increased, the mean weight of prey within the stomach (mW/ST) increased.

• Korean Journal of Environmental Biology
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• v.40 no.3
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• pp.275-280
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• 2022

Suspended solids play an important role in the growth and survival of aquatic organisms. The marine zooplankton species tested in this study were Tigriopus west (Copepoda) and Haustorioides koreanus (Amphipoda) sampled from the intertidal zone, including Artemia nauplii(Branchiopoda) hatched from cysts. The study design included six concentrations (0, 50, 100, 250, 500, and 1,000mg L^-1) of the suspended test particles assayed in triplicate. Experimental cultures in 500 mL-round polycarbonate bottles were subsampled after 96 h to count dead zooplankton. The culture bottles were agitated at 4 RPM on a rotating wheel at 23℃ and 30 PSU. The survival rates of Artemia nauplii and T. west were not affected by suspended solid concentrations higher than 50.0 mg L^-1, whereas the survival rate of H. koreanus decreased with increasing concentrations (p<0.05). In conclusion, H. koreanus and T. west, which were continuously exposed to suspended solid concentrations higher than 50.0 mg L^-1, were affected by low-intensity ecological stress. However, in the case of H. koreanus, a concentration of 50.0 mg L^-1 may be considered to be the limit of tolerance to suspended solids, suggesting that the number of individuals who eventually die will increase if continuously exposed.

• Korean Journal of Ecology and Environment
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• v.44 no.1
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• pp.9-21
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• 2011

This study is conducted to know the change in water environment of Lake Hwajinpo from 2000 to 2008 with physico-chemical parameters; salinity, dissolved oxygen, total phosphorus and total nitrogen and others. And zooplanktons and phytoplanktons were studied from 2007 to 2008. From the water quality data of Lake Hwajinpo from 2000 to 200S; water temperature, salinity, transparency, chemical oxygen demand and dissolved oxygen ranges are $2.8{\sim}29.4^{\circ}C$, 0.23~33.2‰, $0.2{\sim}1.8\;m$, $0.2{\sim}20.2\;mg\;L^{-1}$ and $0.1{\sim}17.4\;mg\;L^{-1}$ and the average values are $18.0^{\circ}C$, 15.7‰, 0.7 m, $5.7\;mg\;L^{-1}$ and $8.0\;mg\;L^{-1}$, respectively. Total phosphorus (TP) and total nitrogen (TN) ranges are $0.024{\sim}0.869\;mg\;L^{-1}$ (average 0.091) and $0.240{\sim}5.310\;mg\;L^{-1}$ (average 1.235). Average TN/TP ratio is 16.4. The annual variations in COD, TP, TN and Chl.${\alpha}$ are compared. COD in 2000 is $4.83\;mg\;L^{-1}$ and 2008 is $1.80\;mg\;L^{-1}$ which is reduced by $0.34\;mg\;L^{-1}$ every year. TP in 2000 is $0.07\;mg\;L^{-1}$ and 2008 is $0.05\;mg\;L^{-1}$ reduced gradually. Yearly reduction in TN is $0.09\;mg\;L^{-1}$, in 2000 and 2008 the values are $1.54\;mg\;L^{-1}$ and $0.77\;mg\;L^{-1}$ respectivly. Chl.${\alpha}$ in 2000 is $46.30\;{\mu}g\;L^{-1}$ and $5.78\;{\mu}g\;L^{-1}$ in 2008; yearly reduction is $4.50\;{\mu}g\;L^{-1}$. The tropic state index (TSI) in south and north parts of Lake Hwajinpo in 2000 are 67 and 63 which are reduced to 63 and 59 in 2008 respectively. North and south part of Lake Hwajinpo have 67 species of phytoplankton under 47 families in 2007 and 2008. Dominant species in south part in 2007 are; Asterococcus superbus in May, Lyngbya sp. in September and Trachelomonas spp. in November and in 2008 Anabaena spiroides in August are abundant and varies with time. Zooplankton species in Lake Hwajinpo are 25 of 25 families. Dominant species in south part in May and August 2007 and May and November in 2008 Copepoda larvae and in September 2007 Protozoa spp. of Protozoan and Brachionus plicatilis and Brachionus urceolaris of Cladocera in August 2008. Dominant species in north part Asplanchna sp. of Cladecera in August and November 2007 and rest of the time are larvae of Copepoda. In this way, the water quality of Lake Hwajinpo is changing with slow rate in the long period specially nutrients concentration (TP, TN etc) is decreasing.

• Korean Journal of Environmental Biology
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• v.26 no.4
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• pp.355-366
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• 2008

The composition and abundance of mesozooplankton were studied from the five stations on the Bulgap stream near Yeonggwang, Jeollanamdo, Korea. Mesozooplankton samples were collected bimonthly in April, July, August, October, and December 2006 and February 2007. Total 44 taxa of mesozooplankton occurred with the highest abundance (31$\sim$53,230 indiv. m$^{-3}$) in October, and the fewest (16$\sim$97 indiv. m$^{-3}$) in December. Diversity index is the highest in July (1.072) and the lowest in October (0.386). The two copepod species, Pseudodiaptomus inopinus and Macrocyclops albidus were dominant during the study periods. A brackishwater species, P. inopinus occurred in the Bulgap stream during from August 2006 to February 2007. This species was the most dominant species (53,010 indiv. m$^{-3}$) in the stations that usually have low salinities (0.1$\sim$14.0 psu). M. albidus was predominated during from April to August 2006 in the freshwater stations.

• Journal of Korean Society of Environmental Engineers
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• v.39 no.3
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• pp.132-139
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• 2017

Endocrine disrupting chemicals (EDCs) interfere with endocrine system in organisms, and have different mode of actions compared to conventional chemicals. Therefore, EDCs specific ecotoxicity tests and assessments have been globally developed by some organizations such as OECD, ASTM, and USEPA. In Korea, researches on EDCs and monitoring of EDCs in domestic environments were also continued. However, Korean ecotoxicity test guidelines for EDCs are not suggested till date. The purpose of this study is to review and analyze international ecotoxicity test guidelines for EDCs and the compare ecotoxicity methods and toxicity endpoints among standard test guidelines. We found that there are very limited EDCs specific soil ecotoxicity test guidelines (only in ASTM) compared to aquatic ecotoxicity test guidelines. Currently, fish, amphibian, waterflea, copepoda, earthworm, white worm, springtail, nematode, mite, and midge are suggested as standard ecotoxicity test species for EDCs. Reproduction, hormones, growth, vitellogenin, sex retio and development were proposed as endpoints for EDCs ecotoxicity. This study provided the comparison of EDCs specific ecotoxicity methods and endpoints between standard test guidelines, and suggested the further research to develop the method for assesseing ecotoxicity of EDCs.