• Molecules and Cells
• /
• v.23 no.3
• /
• pp.379-390
• /
• 2007

We sequenced and characterized the complete mitochondrial genome of the Japanese fish tapeworm D. nihonkaiense. The genome is a circular-DNA molecule of 13607 bp (one nucleotide shorter than that of D. latum mtDNA) containing 12 protein-coding genes (lacking atp8), 22 tRNA genes and two rRNA genes. Gene order and genome content are identical to those of the other cestodes reported thus far, including its congener D. latum. The only exception is Hymenolepis diminuta in which the positions of trnS2 and trnL1 are switched. We tested a PCR-based molecular assay designed to rapidly and accurately differentiate between D. nihonkaiense and D. latum using species-specific primers based on a comparison of their mtDNA sequences. We found the PCR-based system to be very reliable and specific, and suggest that PCR-based identification methods using mtDNA sequences could contribute to the study of the epidemiology and larval ecology of Diphyllobothrium species.

• Journal of fish pathology
• /
• v.23 no.3
• /
• pp.343-355
• /
• 2010

This study was conducted to investigate the dietary effects of lactic acid bacteria (LAB) supplementation on growth, hematological and immune responses of grey mullet, Mugil cephalus. Three replicate groups of grey mullet (body length, $62.8{\pm}1.04\;mm$ ; body weight, $3.2{\pm}0.13\;mg$) were fed the experimental diets with 0 (control), 1, 2.5 and 5,0 % of LAB for 3 months. Total body length growth rate was increased in 2.5 % supplementation group compared to control (P<0.05). No differences were observed in hematological parameters (hematocrit, hemoglobin, RBCs) and serum chemistry (calcium, magnesium, total protein, glucose, GOT and GPT). The antioxidant activity of grey mullet fed the 5.0 % LAB diets was significantly higher than that of other groups (P<0.05). Both intracellular superoxide anion production and lysozyme activity of kidney were higher in the 2.5 % LAB diet than in the control (P<0.05).

• Journal of fish pathology
• /
• v.34 no.2
• /
• pp.149-159
• /
• 2021

Genus Megalocytivirus cause red sea bream iridoviral disease (RSIVD) and scale drop disease (SDD). Based on the phylogeny of the major capsid protein (MCP) and adenosine triphosphatase (ATPase) genes, megalocytiviruses except for SDD virus (SDDV) could be three different genotypes, red sea bream iridovirus (RSIV), infectious spleen and kidney necrosis (ISKNV), and turbot reddish body iridovirus (TRBIV). In this study, primary cells derived from the caudal fin of rock bream (Oplegnathus fasciatus) grew at 25℃ in Leibovitz's medium supplemented with 10% (v/v) fetal bovine serum and primocin (100 ㎍/mL). Rock bream fin (RBF) cells exhibited susceptibility to infections by different genotypes of megalocytiviruses (RSIV, ISKNV and TRBIV) with the appearance of cytopathic effects with an increase in the viral genome copy number. Furthermore, compared to grunt fin (GF) cells, even though 10 times lower number of RSIV genome copies were inoculated in RBF cells, viral genome copy number produced on RBF cells were 44 times higher than that of GF cells at 7 d post-inoculation. As the isolated RBF cells are sensitive to different genotypes of megalocytiviruses (RSIV, ISKNV and TRBIV), they can be used for future studies regarding in vitro viral infection and subsequent diagnosis.

• Journal of fish pathology
• /
• v.34 no.2
• /
• pp.225-231
• /
• 2021

In biofloc culture for olive flounder, Paralichthys olivaceus, the possibility of antibiotics treatment was investigated against edwardsiellosis. After inducing edwardsiellosis by immersion in Edwardsiella tarda 1.2 × 10⁵/mL suspension, the survival trends on various biofloc water management and some physiological changes were observed. For biofloc water management, six types of water treatments were carried out, which were no exchange without antibiotics as negative control, the exchange to stored biofloc water, the exchange to stored biofloc water with 20% flow-through, the exchange to fresh biofloc water, half fresh biofloc water and half sea water, and the complete flow-through. There was no significant physicochemical change on water qualities in any type. The exchange to fresh biofloc water was shown the highest survival ratio as 72.3%, and in case of stored biofloc water with 20% flow-through, the survival ratio was also significantly high as 62%. Plasma glucose, cholesterol, total protein, calcium, and magnesium were analyzed as physiological index. Mostly, there was no significant change, but plasma cholesterol showed an initial decrease in low survival group, and an initial increase with high survival group. Consequently, antibiotic treatment against a bacterial disease during biofloc culture is possible as long as the biofloc water management follow along properly.

• Journal of Microbiology and Biotechnology
• /
• v.32 no.1
• /
• pp.64-71
• /
• 2022

The discarding of wastes into the environment is a significant problem for many communities. Still, food waste can be used for lactic acid bacteria (LAB) growth. Here, we evaluated three growth media equivalent to de Mann Rogosa Sharpe (MRS), using apple bagasse, yeast waste, fish flour, forage oats, and cheese whey. Cell-free supernatants of eight LAB strains were tested for antimicrobial activity against nine indicator microorganisms. The supernatants were also evaluated for protein content, reducing sugars, pH, and lactic acid concentration. Cell-free supernatants from fish flour broth (FFB) LAB growth were the most effective. The strain Leuconostoc mesenteroides PIM5 presented the best activity in all media. L. mesenteroides CAL14 completely inhibited L. monocytogenes and strongly inhibited Bacillus cereus (91.1%). The strain L. mesenteroides PIM5 consumed more proteins (77.42%) and reducing sugars (56.08%) in FFB than in MRS broth (51.78% and 30.58%, respectively). Culture media formulated with agroindustrial wastes positively improved the antimicrobial activity of selected LAB, probably due to the production of antimicrobial peptides or bacteriocins.

• Fisheries and Aquatic Sciences
• /
• v.26 no.9
• /
• pp.525-534
• /
• 2023

Vitamin C plays an important role for fish survival, growth and disease resistance. However, the optimal vitamin C for rearing red drum Sciaenops ocellatus juveniles in Vietnam is not known. To address this issue, a 70-day feeding trial was conducted to evaluate the optimal dietary vitamin C requirements for red drum juveniles. Seven isonitrogenous (55.35% protein) and isolipidic (9.07% lipid) diets were formulated to include graded vitamin C concentrations of 23.2, 124.5, 235.2, 423.8, 626.7, 824.6, and 1,027.3 mg/kg, respectively. The results showed that fish fed on 423.8 mg/kg vitamin C diet had the highest growth rate, which can be linked to the increased feed utilization. Broken-line analysis indicated that the optimal dietary vitamin C requirements of red drum juveniles were 342.92 and 405.80 mg/kg for growth parameters, feed utilization, body composition and biochemical parameters of serum. Based on these parameters the optimal vitamin C supplementation level for red drum juveniles was estimated in the range of 342.92-405.80 mg/kg vitamin C in the diets with direct applications in producing artificial feed for rearing juveniles of this species in Vietnam.

• Journal of fish pathology
• /
• v.36 no.2
• /
• pp.349-360
• /
• 2023

Common carp (Cyprinus carpio) (Weight 23.05 ± 6.98 g, Length 12.65 ± 1.38 cm) were exposed to waterborne nitrite at 0, 50, 100, 200, 400 and 800 mg NO₂ ^-/L for 96 hours. The lethal concentration 50 (LC₅₀) of C. carpio exposed to waterborne nitrite was 398.6 mg NO₂ ^-/L. Hemoglobin, hematocrit and RBC count were significantly decreased by waterborne nitrite exposure. The MCV (mean mean corpuscular volume) (µl), MCH (mean corpuscular hemoglobin) (pg) and MCHC (mean corpuscular hemoglobin concentration) (%) were significantly increased. The inorganic component, plasma calcium, was significantly increased, and the organic components such as plasma cholesterol and total protein were significantly increased showing a similar tendency with calcium. In enzymatic components, the AST and ALT were also significantly increased by nitrite exposure. The results of this study indicate that exposure to nitrite can affect the survival and hematological physiology of C. carpio.

• Proceedings of the Korean Aquaculture Society Conference
• /
• 2003.10a
• /
• pp.126-126
• /
• 2003

Performance of a laboratory scale closed seawater recirculating aquaculture system was evaluated. Twenty-kg Korean rockfish (130 fish) with an average body weight of 153.8 g was stocked. Over 107-day culture period, fish reached final density of 51.7 kg/m$^3$ (initial density, 33.3 kg/m$^3$) on the culture tank volume basis. On a daily basis, water addition was 3.4% of the total water volume in the system. Total ammonia nitrogen (TAN)concentrations were below 1 mg/L and nitrite nitrogen (NO$_2$-N) concentrations were within the range of 1-3 mg/L on most sampling days. TAN was removedin bead and sand filters and it was removed or produced in the sedimentation basin. Basically, NO$_2$-N was removed in the bead and sand filters while it was either removed or produced in the sedimentation basin. Nitrate nitrogen (NO$_3$-N) was produced in the bead filters and removed in the sand filter and sedimentation basin. Foam fractionator performed well in the recirculating system. The maximal daily removal values for total suspended solids (TSS) and protein were 10,9 g and 1.4 g, respectively. Whole water quality parameters were within the levels commonly recommendedfor fish culture on most of the sampling days. However, further studies are needed to evaluate the commercial feasibility of this system because of the small-scale system used in present experiment. At least, present study still provides some basic information for further studies of this kind of system.

• Journal of Aquaculture
• /
• v.9 no.3
• /
• pp.233-237
• /
• 1996

A growth study was conducted to investigate the effect of stocking density on performance of juvenile fat cod (Hexagrammos otakii Jordan et Starks.). Fish averaging 13 g were stocked into duplicate tanks ($250\;{\ell}$ each) at four different densities of 330 g/$100\;{\ell},\;660\;g/100\;{\ell},\;990\;g/\;100\;{\ell}$, and $1330\;g/100\;{\ell}$, and fed MP diet containing $50\%$ frozen horse mackerel and $50\%$ commercial binder meal for 2 months. Weight gain, feed efficiency, survival rate, and protein retention were decreased as density increased. Whereas these parameters were not significantly different (P>0.01) fish stocked at initial stocking densities of $330\;g/100\;{\ell},\;660\;/g/100\;{\ell}\;and\;990\;g/100\;{\ell}$. Moisture and lipid content of whole body were not affected by stocking densities (P>0.01). These results indicate that stocking density should be considered, and $1{\~}2$ kg fish/$100\;{\ell}$ final stocking density for juvenile fat cod could be used to decrease production cost for the indoor tank (culture) system.

• Proceedings of the Korea Society of Poultry Science Conference
• /
• 2004.11a
• /
• pp.13-15
• /
• 2004

Telomeres are the end of chromosomes and consist of a tandem repeat sequence of (TTAGGG)n and associated proteins. Telomeres are essential for chromosome stability and are related with cell senescence and apoptosis. This study was carried out to analyze the amount of telomeric DNA of chicken lymphocytes, which is to considered as bio-marker. The amount of telomeric DNA of lymphocytes in Korean Native Chicken and White Leghorn was analyzed by quantitative-fluorescence in situ hybridization (Q-FISH) technique using the chicken telomeric DNA probe. Telomere quantifies were compared among breeds, ages and sex, and the relationship between the amount of telomeres and their productive trait was also analyzed. Comparing the amount of telomeric DNA on lymphocytes during growing period, the amount of telomeres was gradually decreased as growing older. The telomere quantity was also significantly different in breeds and sex. Estimating correlation coefficient, the amount of telomeres was positively correlated to sexual maturity and body weight but negatively correlated to hen day egg production and egg weight. These results implicate the telomere quantity is considered as an individual bio-marker.