• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.22 no.4
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• pp.56-60
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• 1986

The purpose of this study is to find the light intensity which induced maximum gathering rate and to observe the variation of the gathering rate both in daytime and at night by using rock trout, He.'~agrammos otakii (Jordan et starks). An experimental tank (360L x SOW x 55H cm) was set up in a dark room. An illumination system was attached to the end of one side of the tank to control horizontal light intensity. Six artificial light sources were prepared by combination of two light bulbs (5 W, 150 W) and seven filters. During the experiment water depth was maintained 50 em level in the tank. The tank was marked into six longitudinal sections each being 60 em long to observe the distribution of fish. The fish were acclimatized in dark condition for 50 minutes prior to the main experiment. Upon turning on the light, the number of fish in each section was counted 40 times every 30 seconds. and the gathering rate was obtained from the average number of fish in each section. The light intensity inducing maximum gathering rate was O. 7 lux (0. 5~1. 1 lux) in the daytime and 5. 2/ux (3.2-7.7 lux) at night. The variation of the gathering rate of fish in illumination time was sma II and showed the decreasing trend.

• Journal of fish pathology
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• v.26 no.2
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• pp.123-128
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• 2013

The outbreak of haemorrhagic speticemia and dermal lesions in cultured Rock sea breem in Jeju Island are frequently associated with keratitis. Prolonged infection leads to the symptoms accompanied by necrosis of fin and skin and the fishes died. Present study aims to study the histopathological changes of diseased fish muscle tissue. The tissue at the initial stage of infection showed normal muscular texture, however in the late stages of infection, muscular lesion had been expanded and hence, necrosis had progressed deeply into muscle tissue. Mild tissue in caudal fin was found with more necrosis, and gill tissues were also collapsed. In Kidney, renal tubules were teared along with tissue destruction (Espada, J et al, 1993). Hence in the present study, we examined the histopathological variation of the infection fishes, and this basic data would be used for future research of in haemorrhagic specticemia and dermal diseases.

• Journal of fish pathology
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• v.28 no.2
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• pp.99-107
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• 2015

Despite its economic importance as an aquaculture species, the molecular and genetic information regarding physiologically important elements in rock bream (Oplegnathus fasciatus) is not completely understood. Rab proteins play a vital role in cellular mechanisms and immunity as one of the key regulators of membrane trafficking. In this investigation, a Rab gene, named as RbRab-5C-like, was identified from Oplegnathus fasciatus. RbRab-5C-like protein exhibited high homology with Rab proteins of other species and possessed signature characteristics of Rab proteins with four conserved cysteine residues. Phylogenetic analysis showed that RbRab-5C-like clustered with other fish counterparts. The RbRab-5C-like genomic sequence possesses six exons and five introns. Transcriptional analysis revealed that RbRab-5C-like was ubiquitously expressed in all examined tissues with the highest expression occurring in the liver. While the structural and homologic characteristics of RbRab-5C-like suggest a strong conservation of this element in different species, its mRNA distribution implies a wide range of biological significance in rock bream.

• Journal of fish pathology
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• v.26 no.3
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• pp.295-301
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• 2013

Ferritin is an evolutionarily conserved protein that plays an important role in iron storage and detoxification. In this study, the gene encoding a ferritin H subunit homologue (RbFH) was cloned from rock bream (Oplegnathus fasciatus) and analyzed at the expression. The full-length ferritin H cDNA was 1162 bp long and contained an open reading frame (ORF) of 531 bp that encoded 177 amino acid residues with a predicted molecular mass of 20.8 kDa. The 5' UTR was 297 bp in length, and the 3' UTR 298 bp, and preceded by a 5'-untranslated region that contains a putative Iron Regulatory Element (IRE). The deduced amino acid sequence of RbFH shares extensive sequence identities with the H ferritins of a number of fish species and contains the ferroxidase center that is preserved in ferritin H subunits. Examination of tissue specific expression indicated that RbFH expression was most abundant in PBLs, RBC, liver and muscle.

• Tunnel and Underground Space
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• v.12 no.1
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• pp.37-42
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• 2002

A back analysis algorithm was developed to determine the major parameters for tunnel design; the elastic modulus(E) and the ratio of horizontal to vertical stress(K). The algorithm is based on direct search method and was coded by FISH language of FLAC, a commercial finite difference program. Developed code was applied on some models to verify the validity and estimate the efficiency of the algorithm. Verification by theoretical solutions and published results of Gens' research, was successful.

• Journal of fish pathology
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• v.19 no.2
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• pp.109-117
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• 2006

A new myxosporean species Ceratomyxa oplegnathus n. sp. was found from the gallbladder of cultured rock bream, Oplegnathus fasciatus. Mature spores were 44.14 ± 2.41 (39.04-48.41) ㎛ in length, 8.52 ± 0.36 (7.9-9.26) ㎛ in width in sutural view. Spores contained two spherical polar capsules measuring 3.04 ± 0.2 (2.71-3.37) ㎛ in diameter and a binucleated sporoplasm. Each polar capsule had a 5-6 coiled polar filament, and was situated near the sutural line. In ultrastructural observation, asynchronous divisions of generative cells without pansporoblast formation gave arise to 2 spores within a trophozoite. Sporoplasmic cell in the sporoblast was binucleated, and capsulogenic cells had large amounts of rough endoplasmic reticulum, external tubules, and capsular primordia.

• Journal of fish pathology
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• v.23 no.3
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• pp.429-440
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• 2010

We constructed a rock bream (Oplegnathus fasciatus) gill cDNA library and a total of 1450 expressed sequence tag (EST) clones were generated. Gene annotation procedures and homology searches of the sequenced ESTs were locally done by BLASTX for amino acid similarity comparisons. Of the 1450 EST clones, 1022 EST clones showed significant homology to previously described genes while 428 ESTs were unidentified, and 259 clones were hypothetical, or unnamed proteins. Encoding 313 different sequences were identified as putative bio-defense genes or genes associated with immune response.

• Journal of fish pathology
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• v.23 no.2
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• pp.229-238
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• 2010

We constructed a rock bream (Oplegnathus fasciatus) liver cDNA library and a total of 1533 expressed sequence tag (EST) clones were generated. Gene annotation procedures and homology searches of the sequenced ESTs were analyzed using BLASTX. Of the 1533 EST clones, 1165 different ESTs showed significant homology to previously described genes while 368 ESTs were unidentified, hypothetical, or unnamed proteins. Encoding 106 different sequences were identified as putative bio-defense genes or genes associated with immune response.

• Journal of fish pathology
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• v.23 no.2
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• pp.177-187
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• 2010

The Interferon stimulated gene 15 (ISG15) is strongly induced in many cell types by IFNs, viral infections, and double-stranded RNA (poly I:C). The ISG15 homologue cDNA was isolated from the rock bream LPS stimulated leukocyte cDNA library. The rock bream ISG15 homologue was found to consist of 833 bp encoding 157 amino acid residues. Compared with other known ISG15 peptide sequences, the most conserved regions of the rock bream ISG15 peptide were found to be the tandem ubiquitin-like domains and a C-terminal LRLRGG conjugating motif, characteristic of mammalian and non-mammalian ISG15 proteins. Phylogenetic analysis based on the deduced amino acid sequence revealed a homologous relationship between the ISG15 sequence of rock bream and that of Atlantic salmon, Atlantic cod, northern snake head, black rockfish and olive flounder. The expression of the rock bream ISG15 molecule was induced in the peripheral blood leukocytes (PBLs) from 1 to 24 h following poly I:C stimulation, with a peak at 3 h post-stimulation. The rock bream ISG15 gene was predominantly expressed in the PBLs, spleen and gill.

• Journal of fish pathology
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• v.23 no.3
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• pp.281-291
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• 2010

Crytocaryon irritans infection of rock bream was investigated in embankment fish farm from July to December 2009. Prevalence variation was 20.0~88.0% that was high in september and was low in July. While no mortality was found in July and August, it occurred after mid september. Environmental conditions during the survey period were water temperature $19.3{\sim}24.3^{\circ}C$, dissolved oxygen $5.0{\sim}7.1\;mg\;L^{-1}$ and salinity 31.9~33.7 psu, and the water temperature during mortality season was $24.0^{\circ}C$. External symptom of the rock bream was secretion mucus but swimming showed fine in the early infected period. While, the symptoms in the severe outbreak season were excess of mucus, falling off tail and congestion, bleeding spot the surface and weakened swimming. We observed free living and parasitic stages in the gills and body surface of rock bream. Hepato somatic index (HSI) was $1.9{\pm}1.1{\sim}3.5{\pm}1.7%$, which was low in the September being mortality season but was high in November. The percentages of hematocrit infected with Crytocaryon irritans were 37.3% and 41.0% in July and August, respectively while they gradually decreased to 32.1% and 24.2% in september and October, respectively. Total cholesterol and Triglyceride values rapidly decreased by October. After mortality, AST and ALT were 7 and 5 folds higher compared to non-mortality season.