• Journal of fish pathology
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• v.25 no.3
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• pp.221-229
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• 2012

Hybrid of red seabream (Pagrus major) and Japanese red seabream (Pagrus major) grew rapidly from to August (WT $19.7^{\circ}C{\sim}24.0^{\circ}C$) while black seabream (Acanthopagrus major) did from September to October (WT $19.9{\sim}23.0^{\circ}C$). Survival rate of hybrids (85.5%) was a significantly higher than those of the other fish species (20%). Green liver syndrome were observed in black sea bream and Japanease red seabream but did not in hybrids. Microcotyle tai infected 0~90% in hybrid, 20~100% in red seabream, 10% in black sea bream and 20~100% in Japanese red seabream but no significant difference was found among each fish species.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.53 no.3
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• pp.451-455
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• 2020

This study evaluated acute toxicity of chlorine dioxide (ClO₂ ) to juveniles of black seabream Acanthopagrus schlegelii (19.4±2.3 g, 10.7±0.4 cm) and red seabream Pagrus major (74.9±8.2 g, 15.9±1.0 cm). Thirty juveniles for each species were exposed to target ClO₂ concentrations of 0, 0.05, 0.1, 0.125, 0.15, 0.2, 0.3, 0.4, and 0.5 mg/L in triplicate for eight days. Half lethal concentrations for 96 hours were found at 0.14 and 0.24 mg ClO₂/L for black seabream and red seabream, respectively. Red seabream larger than black seabream in body weight appears to be more resistance to chlorine dioxide. However, regardless of species or size, specific loading rates of chlorine dioxide to total fish weight (daily feeding amount of ClO₂/total fish weight) were similar, showing 1.3 and 1.1 g ClO₂/kg fish·day^-1 for black seabream and red seabream.

• Journal of fish pathology
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• v.16 no.2
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• pp.75-80
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• 2003

Red scabream, Pagrus major , is a valuable aquaculture species in Korea , but spontaneous eye abnormality occurred in cultured individuals . The incidence of eye abnormality was 4% in the group of cultured red scebream. The abnormality was characterized by unilateral and bilateral exophthalmos, opacity and lens pathology. Lense prolapse was found in two cases. Lenses in diseased fishes was considerably small in diameter and eyes were deformed as a whole. In the group of induced hybrid red scabream Pagrus major (♀) x black seabrearn Acanthopagrus schlegeli (♂), the incidence of eye abnormality wa~ the same 4%, but only opacity was registered. Opacity was also found in two of sixteen examined Wild-caught red seabrcam. Histopathological changes of lenses in cultured red seabreem included vecuolated cytoplasm of lens fibers, necrosis of fibers in central part of lens, folding and increase in thickness of lens capsule, and epithelial proliferation beneath the anterior lens capsule. In affected eyes no parasites or gas bubbles were found.

• Proceedings of the Korean Aquaculture Society Conference
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• 2004.05a
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• pp.419-420
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• 2004

• Korean Journal of Fisheries and Aquatic Sciences
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• v.51 no.2
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• pp.163-169
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• 2018

This study examined the expression of heat shock protein 70 (Hsp70) in red seabream Pagrus major infected by the, acanthocephalan parasites Longicollum pagrosomi. We cloned the full-length Hsp70 cDNA from the liver of the red seabream. The full-length cDNA had a 1,950 bp open reading frame (ORF) that encoded a protein of 650 amino acids. The deduced amino acid sequence of Hsp70 contained all of the conserved Hsp70 family signature sequences and an adenosine triphosphate (ATP)/guanosine triphosphate (GTP) binding motif, including the EEVD (consensus sequence that terminates in Hsp70 family) consensus sequence. The expression of Hsp70 mRNA was upregulated int the fish head-kidney and liver, as determined by quantitative real-time PCR. We quantified the Hsp70 mRNA expression in normal red seabream and fish infected fish by L. pagrosomi. The expression of Hsp70 mRNA was significantly higher in the infected red seabream. These results suggest that Hsp70 play a role of protection against stress and inflammation caused by the parasite and may help maintain homeostasis.

• Journal of fish pathology
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• v.17 no.2
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• pp.105-111
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• 2004

Tissue reactions in gills of cultured red seabream, Pagrus major, toan epitheliocystis infection are described. Basophilic intracellular inclusions in gills contained prokaryotes, most probably a Chlamydia-like organisms according to morphological characteristic. A few types of tissue reaction were found around the inclusions: encapsulation, epithelial hyperplasia, lamellar fusion, and inflammation. It was considered that eosinophilic granule cells and macrophages might take part in defense reactions against this prokaryotic organism.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.46 no.6
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• pp.785-792
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• 2013

Two studies were conducted to investigate the effects of dietary nucleotides (NT) on the growth performance, hematological parameters, and innate immune responses of red seabream Pagrus major. In Expt I, six experimental diets were formulated: a control, four that contained each NT at a level of 0.15% (inosine monophosphate, IMP; adenosine monophosphate, AMP; guanosine monophosphate, GMP; and uridine monophosphate, UMP), and one with a 1:1:1:1 mixture of NTs (IMP, AMP, GMP, and UMP). In Expt II, five experimental diets were formulated that contained 0, 0.1, 0.2, 0.4, and 1.0% IMP (commercial product). Triplicate groups of juvenile (initial body weight 33.1 g) and growing (initial body weight 120 g) red seabream were fed one of the experimental diets to apparent satiation for 8 weeks in Expt I and 12 weeks in Expt II. In Expt I, fish fed diets with NT had higher growth performance than the control group. The nitroblue tetrazolium and lysozyme activities were higher in fish fed the mixed-NT diet, and lowest in the control group. In Expt II, the final body weight and feed utilization of fish fed the 0.1% IMP diet were significantly higher than those of fish fed the control or 1.0% IMP diets. Diet palatability was improved significantly when 0.1% IMP was added. The lysozyme activity was higher in fish fed diets with 0.4-1.0% than in the control group. These results suggest that supplementation of 0.15% IMP and Mixed-NTs in diet can enhance the growth and immune responses in juvenile red seabream. The optimum IMP level appears to be 0.2% in practical feed formulation for growing red seabream.

• Journal of Aquaculture
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• v.11 no.2
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• pp.203-212
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• 1998

As seed production program is growing prosperously in various fishes in southern Korea, disease problems in larval and juvenile stages have emerged as a new research object. The following results were obtained from investigation about environmental factors related to mass mortalities of young Kinki red seabream, Pagrus major in process of artificial seedling production. Total length of red seabream larvae hatched was 2.93mm, and became 18.83~20.12mm at day 40. The first noticeable mortality of red seabream larvae (7.98~9.37mm) occurred in 25~30 day-old fish with the survival rates of 59.8~60.3%. Thereafter the mortality of larvae decreased, survival rate was 20.5~25.45% in day 40. After 20~30 days, the quality of pond water was bellow II class. During the experimental period COD, $PO_4$-P, $NO_2$-N, $NO_3$-N and $NH_$-N increased up to 3, 7, 34, 6 and 8 times, respectively, compared to initial ones. The number of viable bacteria in pond water and seabream larvae were $6.3{\times}10^6$~$2.3{\times}10^7$ cfu/ml, 4.3~$7.4{\times}10^6$ cfu/g in day 25, respectively. Among the isolated bacteria from the diseased red seabream in day 25, Vibrio spp. was considered to be the causative organism. External symptoms of this disease were floated, spined near the surface and inflated abdomen. When the isolated strain of the Vibrio was bathed to seabream larvae, $LD_50$ of seabream larvae was over $10^6$ cfu/ml of Vibrio spp.

• Fisheries and Aquatic Sciences
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• v.12 no.3
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• pp.171-178
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• 2009

The Perciformes include approximately 40% of all bony fishes and are the largest order of vertebrates. This order includes some of the most economically relevant marine fishes, particularly the red seabream, black seabream and rock bream. A 409 bp fragment of the cytochrome b (cyt b) gene and 403 bp and 518 bp fragments of ribosomal RNA (12S and 16S rRNA, respectively) were sequenced from five populations of natural and cultured red seabreams, natural black seabream, and natural and cultured rock breams. The mitochondrial DNA sequences were utilized for the genetic identification and population structural analyses of these three species. Phylogenetic relationships of intra- and inter-species were elucidated using three types of molecular genetic markers from three species of the order Perciformes in Korea. We noted no significant differences in the intra-specific variation of the cyt b and rRNA genes in each population however, inter-specific divergences were greater than intra-specific variation. Inter-specific variation was induced more by transition than transversion type in the cyt b and rRNA genes. The cyt b gene and rRNA genes make it possible to determine the inter-species divergence. The rRNA genes have more conserved sequences than the cyt b gene. Therefore, these genes are expected to prove useful among species belonging to the different genera or families.

• Journal of Aquaculture
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• v.16 no.3
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• pp.165-170
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• 2003

Isolation, cloning and sequencing of red seabream (Pagrus major) somatolactin (rsbSL) cDNA from pituitary gland revealed an open reading frame of 693 bp coding for a pre-growth hormone of 231 amino acids with a 22 amino acid putative signal peptide. Deduced amino acid sequence showed that there was one possible N-glycosylation site at Asn$^{145}$ and seven Cys residues (Cys$_{29}$ , Cys$^{39}$ , Cys$^{66}$ , Cys$^{89}$ , Cys$^{205}$ , Cys$^{222}$ , Cys$^{230}$ ). Except Cys$^{66}$ , others may be involved in disulfide bond formation. The rsbSL presented a 93% amino acid sequence identity with the SL of gilthead seabream (Sparus aurata) and contained the conserved hormone domain region. Expression of rsbSL in E. coli (BL2l) cells and gel analysis revealed a higher molecular weight for rsbSL than expected theoretically, implying posttranslational modifications.