• Journal of Aquaculture
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• v.21 no.1
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• pp.26-33
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• 2008

This study investigated the synergistic effects of dietary supplementation of quartz porphyry(QP) and a laboratory developed feed stimulants, BAISM(BS) on growth performance and utilization as the additives for juvenile eel Anguilla japonica. Six isoenergetic experimental diets(18.2 kJ/g) were formulated to contain 50% crude protein, 15% lipid with or without dietary QP(Song-Gang stone, Davistone, Korea) and BS supplementation. QP and BS were provided at 0% in the control diet($Q_0B_0$) and at 0.7% QP+0% BS($Q_{0.7}B_0$), 0.7% QP+0.3% BS($Q_{0.7}B_{0.3}$), 0.7% QP+0.5% BS($Q_{0.7}B_{0.5}$), 0.7% QP+0.75% BS($Q_{0.7}B_{0.75}$) and 0.7% QP+1.0% BS($Q_{0.7}B_{1.0}$) in experimental diets on dry matter basis. After four weeks of adaptation, triplicate groups of 30 fish initially averaging $15{\pm}0.1g(mean{\pm}SD)$ were randomly distributed into each aquarium, and they were fed one of the experimental diets for 8 weeks. By the end of the feeding trial, weight gain(%), specific growth rate(%), feed efficiency(%) and protein efficiency ratio of fish fed diet $Q_{0.7}B_{0.5},\;Q_{0.7}B_{0.75}\;and\;Q_{0.7}B_{1.0}$, were significantly higher(P<0.05) than those of fish fed the other diets. But, $Q_{0.7}B_{0.5},\;Q_{0.7}B_{0.75}\;and\;Q_{0.7}B_{1.0}$ were no significant differences(P<0.05). In challenge test, fish were infected by intraperitoneal injection of 0.1 mL bacterial suspension with Edwardsiella tarda per fish after the feeding trial. As a result, fish fed QP and BS supplemented diets have a significantly higher cumulative survival rate than those of fish fed control diet(P<0.05). In conclusion, these results indicated that the optimum dietary supplementation level of QP and BS could be approximately 0.7% quartz porphyry+0.5% BAISM($Q_{0.7}B_{0.5}$) of diet based on WG, FER, SGR, PER, cumulative survival rate in juvenile eel A. japonica.

• Journal of Animal Science and Technology
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• v.52 no.4
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• pp.337-346
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• 2010

We report non-specific immune responses and disease resistance against Vibrio anguillarum, Streptococcus iniae and Edwardsiella tarda by dietary supplementation of fermented garlic powder (FGP) in olive flounder for the first time. Four isonitrogenous (45% crude protein) and isocaloric (17.1 MJ/kg) diets were formulated to have 0%, 0.5%, 1% and 2% of the FGP (G-0, G-0.5, G-1 and G-2). The experimental diets were fed to juvenile olive flounder averaging 23.4 g in triplicate groups (90 fish/group) in a flow-through system. After a five-week feeding trial, healthy fish with similar sizes from each tank were selected and injected with 1 ml of three bacteria each to evaluate disease resistance of the fish. During the 5-week feeding trial, the weight gain, specific growth rate, feed conversion ratio, protein efficiency ratio, and survival of the fish were not significantly affected by the experimental diets. However, feed intake was significantly lower (P<0.05) in the fish fed the G-2 diet compared with the control group. Hemoglobin, myeloperoxidase activity, cholesterol and HDL-cholesterol were not different between the dietary groups. However, hematocrit, nitroblue tetrazolium (NBT) activity, and lysozyme activity were increased (P<0.05) with an increment of dietary FGP. Plasma triglyceride of the fish fed the G-0.5 diet was significantly lower than that of fish fed the control diet. The cumulative mortality was lower in the fish fed diets containing FGP compared with the control group in the challenge test except for the bacteria Edwardsiella tarda. The results in this study indicate that dietary supplementation of FGP can enhance the non-specific immune responses and disease resistance of olive flounder against V. anguillarum and S. iniae.

• Journal of fish pathology
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• v.25 no.1
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• pp.21-30
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• 2012

Effects of various concentration of skullcap Scutellaria baicalensis in the diets on a nonspecific immunity and a disease resistance of olive flounder were investigated. After feeding trial, weight gain of fish fed 0.05% skullcap immersed group was higher than that of fish fed 0, 0.1 and 1% skullcap diet but no significant differences were observed among the experimental groups. Furthermore, no significant differences in hematological indices of olive flounder were found among the experimental groups. Lysozyme activity in the serum and kidney of the administrated group(0.05% skullcap immersed group) was significantly higher than the control group. In addition, the chemiluminescent(CL) responses of head kidney leucocytes from the 0.05% skullcap immersed group was significantly higher(P<0.05) than the control group. In the histological results, the 1% skullcap immersed group appeared to have the detrimental effects for fish health. In a challenge experiment with Edwardsiella tarda(GY-01) and Streptococcus iniae(FT5228), relative percent survival (RPS) in the 0.05% skullcap immersed group was higher than the control group injected with E. tarda(GY-01) at $4^{th}$ and $8^{th}$ weeks. The results suggest that the skullcap extract (0.05%) would be effective to enhance the nonspecific immunity and protective ability of olive flounder against fish pathogen such as E. tarda.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.34 no.4
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• pp.412-418
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• 2001

The effects of dietary $\beta$-glucan administration on non-specific immune parameters in common carp, Cyprinus carpio, (1.0 g and 68.7 g of body weight) and flounder, Paralichthys olivcaces (12.1 g and 54.0 g of body weight) were evaluated. All fishes were fed an experimental diet supplemented with $\beta$-glucan at $0.1\%$ per kg diet for 5 weeks. A week intermission with basal diet occurred between first 2 weeks and second 2 weeks of $\beta$-glucan administration, The changes in the numbers of peripheral neutrophils and macrophages were counted under light microscopy and serum lysozyme activity was also analysed at a week of interval during the experiment. Phagocytic activities of leucocytes from the swimm bladder of carp and the peritonium of flounder were measured 5 weeks after feeding. The oral adminisration of $\beta$-glucan induced significant reduction in mortality after an artificial challenge with $1\times10^6$ cells of Aeromonas hydrophila in larger carp and $1\times10^5$ cells of Edwardsiella tarda in larger flounder but did not in other groups. The numbers of peripheral macrophages and neutrophils, phagocytic acitivies of leucocytes, and the activity of serum lysozyme were greatly increased in the fish fed a $\beta$-glucan supplemented diet. These suggest that $\beta$-glucan administration by oral route can enhance leucocyte phagocytic activity, serum lysozymal activity, and survival rate against artificial infections depending on the infected fish size and challenged bacterial concentration.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.41 no.4
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• pp.248-252
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• 2008

A 6-week feeding trial was conducted to investigate effects of dietary supplementation with wood vinegar (WV) as a feed additive for juvenile olive flounder, Paralichthys olivaceus. Eight experimental diets supplemented with 0(control), 0.01, 0.025, 0.05, 0.1, 0.25, 0.5 and 2.0% WV/kg diet($WV_0,\;WV_{0.01},\;WV_{0.025},\;WV_{0.05},\;WV_{0.1},\;WV_{0.25},\;WV_{0.5},\;and\;WV_{2.0}$, respectively) were prepared by mixing with basal diet. After the 6-week feeding trial, fish fed the $WV_{0.1}$ diet had significantly higher weight gain, feed efficiency, and specific growth rate than those of fish fed the other diets(P<0.05). No mortality was observed in the treatment groups fed the experimental diets for 6 weeks. The liver antioxidant activity of fish fed the $WV_{0.01},\;WV_{0.025},\;and\;WV_{0.05}$ diets was significantly higher than that of fish fed the other diets. The lysozyme activity of fish fed the $WV_{0.25}$ diet was significantly higher than that of fish fed the other diets. Fish fed diets supplemented with WV had significantly lower cumulative mortality than that of fish fed the control diet throughout the challenge test, and fish fed the $WV_{0.05}\;and\;WV_{0.1}$ diets had the highest resistance to disease caused by Edwardsiella tarda at day 7 of the challenge test. Therefore, feeding 0.05-0.1% WV/kg diet improves the growth and immune responses of juvenile olive flounder, Paralichthys olivaceus.

• Fisheries and Aquatic Sciences
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• v.14 no.1
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• pp.43-54
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• 2011

Gene structure of copper/zinc-superoxide dismutase (Cu/Zn-SOD; sod1) was characterized in Hemibarbus mylodon (Teleostei; Cypriniformes), an endangered freshwater fish species in Korean peninsula. Full-length cDNA of H. mylodon SOD1 consisted of a 796-bp open reading frame sequence encoding 154 amino acids, and the deduced polypeptide sequence shared high sequence homology with other orthologs, particularly with regard to metal-coordinating ligands. Genomic structure of the H. mylodon sod1 gene (hmsod1; 1,911 bp from the ATG start codon to the stop codon) was typical quinquepartite (i.e., five exons interrupted by four introns); the lengths of the exons were similar among species belonging to various taxonomic positions. The molecular phylogeny inferred from sod1 genes in the teleost lineage was in accordance with the conventional taxonomic assumptions. 5'-flanking upstream region of hmsod1, obtained using the genome walking method, contained typical TATA and CAAT boxes. It also showed various transcription factor binding motifs that may be potentially involved in stress/immune response (e.g., sites for activating proteins or nuclear factor kappa B) or metabolism of xenobiotic compounds (e.g., xenobiotic response element; XRE). The hmsod1 transcripts were ubiquitously detected among tissues, with the liver and spleen showing the highest and lowest expression, respectively. An experimental challenge with Edwardsiella tarda revealed significant upregulation of the hmsod1 in kidney (4.3-fold) and spleen (3.1-fold), based on a real-time RT-PCR assay. Information on the molecular characteristics of this key antioxidant enzyme gene could be a useful basis for a biomarker-based assay to understand cellular stresses in this endangered fish species.

• Journal of Fisheries and Marine Sciences Education
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• v.25 no.6
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• pp.1285-1293
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• 2013

This study was conducted to investigate the effects of dietary inclusion of various additives Solid sulfur, fucoidan, and glucan on growth performance and immune responses in Juvenile olive flounder paralichthys olivaceus. Six experimental diets supplemented with : no additives (CON); 0.5 and 1.0% solid sulfur (S); 0.2 and 0.4% fucoidan (F); 0.1% glucan (G) of these additives diet on a dry-matter basis. Fish averaging $8.2{\pm}0.17g$ were fed one of six experimental diets in triplicate groups for 6 weeks. By the end of the feeding trial, weight gain, feed efficiency, specific growth rate, protein efficiency ratio, hepatosomatic index and condition factor of fish fed diet CON were significantly lower then those of fish fed the all additives diets (P < 0.05). In challenge test, fish were infected by intraperitonel injection of 0.1 ml bacterial suspension with Edwardsiella tarda per fish after the feeding trial. As a result fish fed All additive diet showed a lower cumulative mortality then did fish fed CON diet throughout the challenge test. In conclusion, these results indicated that solid sulfur, fucoidan and glucan enhanced the growth, feed efficiency and non-specific immune activity of juvenile flounder and protect the fish against microbial infections.

• Fisheries and Aquatic Sciences
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• v.18 no.3
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• pp.273-281
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• 2015

The follistatin (FST) gene encodes a monomeric glycoprotein that plays a role in binding and inhibiting the functions of members of the transforming growth factor (TGF)-${\beta}$ superfamily. Thus, FST facilitates a wide variety of functions, ranging from muscle growth, to inflammation and immunity. In this study, we sought to characterize an FST counterpart, RbFST, which was identified from rock bream Oplegnathus fasciatus. The RbFST cDNA sequence (2,419 bp) contains a 933-bp open reading frame (ORF) that encodes a putative amino acid sequence for RbFST (35 kDa). The putative amino acid sequence contains a Kazal-type serine protease inhibitor domain (51-98 residues) and an EF-hand, calcium-binding domain (191-226 residues). Additionally, this sequence shares a high identity (98.7%) with the Siniperca chuatsi FST sequence, with which it also has the closest evolutionary relationship according to a phylogenetic study. Omnipresent distribution of RbFST transcripts were detected in the gill, liver, spleen, head kidney, kidney, skin, muscle, heart, brain, and intestine of healthy animals, with significantly higher expression levels in the heart, followed by the liver tissue. Under pathogenic stress caused by two bacterial pathogens, Streptococcus iniae and Edwardsiella tarda, RbFST transcription was found to be significantly up-regulated. Altogether, our findings suggest the putative role of RbFST in immune related responses against pathogenic infections, further prefiguring its significance in rock bream physiology.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.53 no.2
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• pp.191-202
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• 2020

We evaluated the effects of dietary supplementation of phytosterol on the growth, feed utilization, immunity, digestibility, wound healing ability and disease resistance of olive flounder Paralichthys olivaceus. We conducted two consecutive feeding trials at different growth stages of the fish: EXP-1 (68.9 g) and EXP-2 (16.5 g). The experimental diets were supplemented with graded levels of phytosterol (1% ecdysteroid extracted from Achyranthis radix) at 0, 0.025, 0.05, 0.1, 0.2 and 0.4% (designated as Con, PHY0.025, PHY0.05, PHY0.1, PHY0.2 and PHY0.4, respectively). Dietary phytosterol did not significantly affect growth and cholesterol concentration. Feed utilization was higher in fish fed phytosterol-supplemented diets than in fish fed the control diet. Dietary phytosterol increased innate immunity and digestibility of protein and dry matter. Wound healing ability was also increased by the phytosterol supplementation. The survival against Edwardsiella tarda challenge was higher in fish fed low-phytosterol diets than in fish fed the control diet. The optimum dietary level of phytosterol seems to be approximately 0.05%. The results in this study indicate that the phytosterol could be used as a functional supplement in diets to improve feed utilization, immunity, digestibility and wound healing ability of olive flounder.

• Fisheries and Aquatic Sciences
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• v.14 no.2
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• pp.93-104
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• 2011

Two hepcidin paralogs (ojhamp1 and ojhamp2) were isolated and characterized from a euryhaline Javanese ricefish (Oryzias javanicus: Beloniformes). The ojhamp1 cDNA encoded 90 or 91 amino acids (aa) of a typical HAMP1 preproprotein. This preproprotein is believed to cleave and yield the 66 or 67 aa-proprotein, followed by the 26 aa-mature peptide, composed of 8 conserved cysteine residues and the QSHL amino terminal motif. The ojhamp2 cDNA encoded 89 aa of HAMP2 preproprotein, cleaved to yield a 65 aa proprotein, and subsequently the 25 aa-mature peptide. The mature OJHAMP1 possessed a cationic isoelectric point (pI), whereas OJHAMP2 had an anionic charge. At the genomic level, both ojhamp1 and ojhamp2 share a conserved tripartite structure (three exons interrupted by two introns) with other vertebrate hepcidin genes. However, the ojhamp1 was shown to exist as two distinct mRNA species, encoding 90 or 91 aa, due to alternative splicing at the junction site between intron I and exon II. Both ojhamp1 and ojhamp2 transcripts were detected in a wide range of tissue types with varying levels of basal expression, although the highest expression was observed in the liver for both isoforms. Transcriptional response to bacterial challenge using Edwardsiella tarda showed that ojhamp1 was moderately upregulated in the liver but remained unchanged in the kidney. However, the ojhamp2 was significantly suppressed in both the kidney and liver, suggesting a potential diversification between the two paralogs.