• Parasites, Hosts and Diseases
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• 제22권2호
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• pp.190-202
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• 1984

In an attempt to clarify the epidemiological feature of distomiasis in Tongjin riverside area, the prevalence of distomiasis in the residents and infection rates of the metacercariae in fresh-water fishes were investigated at the upper, middle and lower reaches of the river from January to April, 1984. The results obtained were summarized as follows: 1. Out of a total of 931 fresh-water fishes which composed of 33 different species, 611 fishes(65.6%) of 31 species were found positive with digenetic trematode metacercariae of 16 different species, and there were some differences in infection rates of the metacercariae among the fishes in the 3 parts of the river; 53.8% in upper, 80.7% in middle, and 61.0% in lower reaches, respectively. 2. Infection rates of the metacercariae of Exorchis oviformis, Metagonimus yokogawai, Echinochasmus japenicus, Metorchis orientalis and Clonorchis sinensis in the fishes were 48%,29%, 115, 7.9% and 6.3oA, respectively. 3. The average number of the encysted larvae of Clonorchis found in fish body/gram showed 4.44 in Pseudorasbera larva, Gnathepegon coreanus (1.2), Microphysogoio yaluensis (0.76), Abbottina springeri (0.4), Acanthorhodeus asmussi (0.21) and Cultriculus eigenmanni (0.17), respectively. 4. The average number of the metacercariae of Metagonimus found in fish body/gram disclosed 34.01 in Zacco platypus, Zacco temmincki (16.46), Carassius carassius (5.35), Moroco oxycephalus (1.54) , Aphyocypris chinensis (1.5) and etc., respectively. 5. Detection rates of the eggs of Clonorchis and Metagonimus among residents were 1.1% and 0.8%, respectively, out of a total 923 Persons.

• 한국물환경학회지
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• 제27권6호
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• pp.760-768
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• 2011

Jinwi Stream is considerably polluted. The urban development in a Jinwi Stream basin can make state of aquatic ecosystem worse. However, researches for aquatic ecosystems in Jinwi Stream are insufficient. In this study, biotic indices of periphytic diatoms (DAIpo and TDI), benthic macroinvertebrates (EPT, KSI and ESB) and fish (IBI) were compared with the annual water quality data. Benthic macroinvertebrates indices showed highly significant correlations with concentrations of organic materials and nutrients, while DAIpo, TDI and IBI showed low correlations with them. In particular, ESB can be considered as an useful indicator that reflects the degree of diversity and abundance of biotic community as well as water quality. In polluted and disturbed streams as Jinwi Stream, DAIpo, TDI and IBI appeared to be not available for evaluating and discriminating the water quality, although they have been known as good indices in general streams.

• 한국해양바이오학회지
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• 제3권1호
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• pp.1-6
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• 2008

Angola has a coastline of about 1,650 km long. Two diverging current namely, the Angola current with its warm water from the north and the cold Benguella Current in the south create a strong up-welling with a high productive ecosystem for marine resources. The area from Lobito to the mouth of the Cunene River, also known as the Southern fishing zone is by far the most productive of Angola's fishing zones. In 1977, the total potential of its marine fisheries sector was estimated at more than 700,000 tonnes per annum. In 2003, the Total Allowable Catch (TAC) established for demersal species was 57,600 tonnes and 160,000 tonnes for pelagic species. The most important resources are various marine demersal and pelagic fish including pilchard and the Cape and Cunene horse Mackerel (Tranchurus capensis and T. trecae). Sardinellas (Sardinella aurita and S. maderensis) are fished in parallel with horse mackerel. The rest of the catches are mainly demersal spp. and some deep water crustaceans. The demersal sppecies consist of Hake (Merluccius polli and M. capensis) and the large eye dentex spp. Tunas are caught at certain times of the year whilst some marine shrimp are also harvested from the Angolan waters. Angola also has several high value freshwater fish species, exploited by about 255 fishers. Tilapia sp. is among the most important and abundant fresh water fish found in Angola. Other species include the catfish (Clarias gariepinus) and fresh water prawns (Macrobrachuin rosenbergii). Some aquaculture ponds have been established in the country side, but due to lack of investment, proper training and the impact of civil war have seriously limited developments in the sub sector.

• 한국수산과학회지
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• 제29권3호
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• pp.279-286
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• 1996

틸라피아를 해수에 순치하여 근육의 물성 및 식감을 개선하기 위하여 해수에 순치한 틸라피아를 $0^{\circ}C,\;10^{\circ}C$ 및 $20^{\circ}C$에 저장하면서 사후경직 중에 나타나는 근육의 물리적, 화학적 변화를 조사하였다. 사후경직은 $10^{\circ}C$와 $20^{\circ}C$ 에서보다 $0^{\circ}C$에서 빠르게 진행되었으며, 담수 사육한 것보다 해수 순치한 것이 경직개시 시간이 빨랐다. 사후경직 중 파괴강도와 사후 경직도와의 상관 관계는 없었으며, 파괴강도는 사후 12시간만에 최대로 되었고, 그 이후로는 육의 연화가 일어남으로 인하여 급격하게 저하된 반면에, 사후 경직도는 계속해서 증가하여 18시간 후에 최대치를 나타내었다. ATP 분해속도는 담수 사육어보다 해수 순치어에서 빨랐으며, 저장온도에 따른 분해속도는 $10^{\circ}C$와 $20^{\circ}C$에 비하여 $0^{\circ}C$에 저장한 시료에서 빠르게 나타났다. IMP 및 젖산은 저장온도가 낮을수록 축적속도가 빨랐고, 담수 사육어보다 해수 순치어에서 빠르게 나타났다. 이상의 결과로부터 담수어인 틸라피아를 해수에 순치시킴으로써 사후초기에 경직을 유도하고 근육의 물성을 변화시켜 식감을 증진시킬 수 있을 것으로 생각된다.

• Parasites, Hosts and Diseases
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• 제41권2호
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• pp.117-120
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• 2003

A human Echinostoma hortense infection was diagnosed by gastroduodenoscopy. An 81-year-old Korean male, living in Yeongcheon-shi, Gyeongsangbuk-do and with epigastric discomfort of several days duration, was subjected to upper gastrointestinal endoscopy. He was in the habit of eating fresh water fish. Two live worms were found in the duodenal bulb area and were removed using an endoscopic forcep. Based on their morphological characteristics, the worms were identified as E. hortense. The patient was treated with praziquantel 10 mg/kg as a single dose. The source of the infection in this case remains unclear, but the fresh water fish consumed, including the loach, may have been the source. This is the second case of E. hortense infection diagnosed by endoscopy in Korea.

• 대한약리학회지
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• 제11권1호
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• pp.15-18
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• 1975

The effect of skin extracts of Korean amphibian, poisonous snake and fresh-water fish were determined for their caerulein-like action on rabbit gall bladder strips. The isolated gall bladder strips were prepared according to the technique described by Amer and Becvar(1969). The strips were placed in a bath containing 100ml of Locke-Ringer solution maintained at $38^{\circ}C$. Oxygen was continuously bubbled through the solution. The tension of the muscle strip was initially adjusted to 0.7g. The contractile response was measured isometrically by a force-displacement transducer connected to a polygraph. In this rabbit gall bladder strip caerulein produced contraction of CCK-PZ type. The skin extract of Korean amphibian also elicited similar contraction as caerulein, which extracted from Australian amphibian, Hyla caerulea, by Erspamer et al. The calculated amount was approximately $2{\mu}g$ caerulein per gram of skin tissue in Korean amphibian and the potency was about 1/200 of that seen in Australian amphibian. The contraction of gall bladder strip by our amphibians occurs in decreasing order; Rana Nigromaculata coreana Okada, Rana nigromaculata Hallowell, Hyla arborea japonica Gunther and Bombina orientalis Boulenger. The skin extracts of poisonous snake and fresh-water fish produced no caerulein-like activity.

• The Korean Journal of Ecology
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• 제12권1호
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• pp.51-65
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• 1989

Some aspects of limno-biology of the five dammed lakes such as Tamyang, Changsong, Kwangju, Naju, and Youngsan Lake along the Yongsan River were investigated from June 1986 to July 1988 for the comparison on the lentic ecosystems in relation to the fish fauna. Sixty four fish species representing 48 genera and 21 families of fishes were collected in these dammed areas, which included 29 species of the family Cyprinidea and 40 speaies of the primary fresh-water fishes. Among, these, 12 species such as Rhodeus Acheilognothus yamatsutae, A canathorhodeus gracilis, Sarcocheilichthys nigripinis morii, S. variegatus wakiyae, Gnathopogon strigatus, Squalidus gracilis majimae, Microphysogobio yaluensis, Cobitis longicorpus sp, Liobagrus mediadiposalis and Odontobutis platycephala are enddmic to Korea. Leiocassis nitidus and Gasterosteus aculeatus which occur in these water areas take note of the zooge rographic study of Korea. The fish species in each of the dammed lakes is in proportion of the scale of the lakes such as 32 species in Thamyang, 40 species in Changsong, 24 species in Kwangju, 35 species in Jaju, and 52 species in Yongsan Lake. The dominant fish species of the 4 upper dammed lakes of Thamyang, Changsong, Kwangju and Naju Lake are Zacco platypus and Rhodeus uyekii, while those of Youngsan Lake are Hemiculter eigenmanni and Carassius auratus. This difference of fish species of those areas suggests that the upper damed lake differ from the lower dammed lakes in the habitable condition of fishes. The migratory fish species have significantly declined and will continue to decline in both population size and number of species in the dammed lakes in near future as a result of the dam construction barriers in the river estuary. The major migratory fishes of this water area are as follows; Anguilla japonica, Plecoglossus altivelis, Hypomesus olidus, Gasterosteus aculeatus, Konosirus Punctatus, Coilia ectens, Hemirhampus sajori, Mugil cephalus. Acanthogobius flavimanus, and Takifugu ocellatus.

• 한국수산과학회지
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• 제55권5호
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• pp.541-548
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• 2022

Biofloc technology (BFT) systems provides an additional protein source for fish by converting waste in microbial flocs. Therefore, we aimed to determine the difference in the protein levels of the diet of Far Eastern catfish Silurus asotus reared in BFT and FW systems. We applied a two-way (six protein levels × two aquaculture systems) ANOVA design. We formulated six experimental diets to contain different protein levels (CPs)- 20%, 25%, 30%, 35%, 40% and 45%-referred to as the CP20, CP25, CP30, CP35, CP40 and CP45 diets, respectively. We randomly distributed 900 fish into 36 (18 each for BFT and FW), 300 L tanks (25 fish/tank) with three replications of each diet for 4 weeks. The weight gain (WG) and specific growth rate (SGR) considerably improved as the dietary protein level increased in the formulated diets. The BFT fish showed higher growth performance with any experimental diet than the FW fish. The growth performance of the fish fed the BFT-CP35 diet was higher than that of the fish fed the FW-CP45 diet. In conclusion, the cultivation of Far Eastern catfish (S. asotus) in BFTs can be carried out under reduced dietary protein levels.

• Fisheries and Aquatic Sciences
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• 제26권10호
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• pp.583-592
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• 2023

Celebes rainbow (Marosantherina ladigesi) is one of Indonesia's exported ornamental fish commodities, but the exploitation of this fish only relies on wild catches. The rise of unlimited fishing, especially those using poison, has changed the aquatic environment, threatening sustainability and causing fish extinction. This study aimed to evaluate the effectiveness of several types of feed in improving the absolute growth rate (AGR), specific growth rate (SGR), survival rate (SR), feed conversion ratio (FCR), feed efficiency (FE), hematology, and immune response of Celebes rainbow. The fish used in this study were male ornamental Celebes rainbow (M. ladigesi) weighing 1.32 ± 0.21 g/ind, reared in 54 L-aquariums at a stocking density of 30 individuals/aquarium for six weeks. The fish were fed according to the test diet consisting of live Tubifex sp worms, dry Tubifex sp worms, Spirulina platensis, and crumble pellets. The parameters observed were AGR, SGR, SR, FCR, FE, hematology, intestinal histology, liver histology, and a challenge test with the pathogenic bacteria Aeromonas hydrophila. The results showed that fish-fed live Tubifex sp worms had better AGR, SGR, SR, FCR, FE, hematology, and disease resistance compared to all other treatments. These results indicate that live Tubifex sp worms are the best feed for rearing Celebes rainbow.

• 한국동물학회지
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• 제30권4호
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• pp.417-431
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• 1987

Isozyme analysis, morphometric comparison, and artificial hybridization test wereperformed to elucidate the patterns of genic variation, morphological differentiation, genetic incompatibility, and a probable path in speciation between two MDH allelotypes (MM type and MS type) of the Dark Chub Zacco temmincki, a fresh water fish inhabiting in Korean waters. The degree of genic variation of MS type(HD=.023, HG=.021) was twofold higher than that of MM type (HD=.013, HG=.014) but both allelotypes were far less than the average genic variation of fresh water Bish in general. The average genetic similarities among 7 populations of MM type and 6 Populations of MS type were S=.947 and S=.966 respectively, whereas the value between two allelotypes was S=.853. Presumed divergent time of two allelotypes was estimated to be about 700 thousand years ago. Discriminant function analysis based on 18 morphometric characters of 302 specimens representing 12 populations revealed no morphological difference between two allelotypes. Artificial hybridization test indicates that there is an obvious genetic incogpatibility between two allelotypes and therefore it is assumed that isolating mechanism is completed.