• Journal of Aquaculture
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• v.20 no.3
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• pp.147-153
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• 2007

The present study was performed to evaluate sitological quality of the cultured and wild river puffer, Takifugu obscurus. Proximate composition, the content of extractive nitrogen, the content of nucleotides and their related compounds, total and free amino acid, and fatty acids were analysed and sensory evaluation in the muscle of the river puffer were compared. The cultured river puffer had a higher moisture content compared to the wild fish, while there was no significant difference in crude lipid, crude protein and ash contents. Nucleotides and their related compounds including ATP, ADP, AMP, IMP, HxR and Hx were detected. The result from analyzing ATP-related compound showed difference in total content by wild and cultured river puffer, and IMP content that had largest influence upon the savory taste of sliced raw fish, was higher in the cultured fishes than wild ones. Breaking strength level of the wild river puffer was higher than that of the cultured fish. High levels of C16:0 and C18:0 were shown in all samples and -3 polyunsaturated fatty acid content were not different between the cultured and wild river puffers (P>0.05). Total 17 amino acids were detected in the samples, and most of the samples had high contents of glutamic acid, aspartic acid, lysine and leucine and low contents of cystine, histidine, methionine and tyrosine. The result from surveying free amino acid content of wild and cultured river puffer showed difference in content, but generally taurine and lysine content for the whole free amino acid held the most part. There was no significant difference in texture, flavor and overall acceptance score between the cultured and wild fishes (P>0.05).

• Korean Journal of Fisheries and Aquatic Sciences
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• v.47 no.4
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• pp.390-398
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• 2014

We conducted an 8-week feeding trial to evaluate dietary lipid sources on the growth performance and body composition of juvenile river puffer fish Takifugu obscurus. Nine experimental diets were formulated with fishmeal as the major protein ingredients, providing 50% crude protein. The experimental diets contained either beef fallow (BF), soybean oil (SO), rapeseed oil (RO), or linseed oil (LO). Each of these diets was then supplemented or not with 0.5% n-3 HUFA (BFH, SOH, ROH, and LOH), resulting in a total of eight experimental diets. The control diet contained fish oil (FO) as the lipid source. Fish averaging $10.3{\pm}0.03g$ were fed the experimental diets in randomly selected triplicate groups for 8 weeks. Weight gain and feeding efficiency of fish fed the FO and SOH diets were significantly higher than those of fish fed BF or RO (P<0.05), but these diets did not differ significantly from the other diets. The protein efficiency ratio of fish fed the SOH diet was significantly higher than that of fish fed the BF, SO, or RO diets (P<0.05), but these were not significantly different from the other diets. The specific growth rate of fish fed the FO and SOH diets was significantly higher than that of fish fed the BF diet (P<0.05). Whole body DHA and n-3 HUFA contents of fish fed the FO diet were significantly higher than those of fish fed the SO, RO, or LO diets (P<0.05), but were not significantly different from the other diets. These results indicate that soybean oil and linseed oil could replace up to 100% of fish oil in the diet containing 60% fishmeal for river puffer fish.

• Journal of Fisheries and Marine Sciences Education
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• v.26 no.4
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• pp.868-876
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• 2014

This study was conducted to estimate the optimum dietary protein to energy (P/E) ratio in juvenile river puffer. Nine experimental diets were formulated with three energy levels and three protein levels at each energy levels. Three energy levels of 3000, 3750 and 4500 kcal diets were included at 45, 50 and 55% crude protein (CP) levels, respectively (45P3000, 45P3750, 45P4500, 50P3000, 50P3750, 50P4500, 55P3000, 55P3750 and 55P4500). Fish averaging $3.43{\pm}0.02$ g randomly were fed the experimental diets in triplicate groups for 8 weeks. Weight gain of fish fed the 50P4500 diet were significantly higher than that of fish fed the 45P3000, 45P3750, 45P4500, 50P3000 and 50P3750 diets (P<0.05), but there was not significantly different from that of fish fed the 50P4500, 55P3750 and 55P4500 diets. Feed efficiency of fish fed the 50P4500 diet were significantly higher than that of fish fed the 45P3000, 45P3750, 45P4500, 50P3000 and 50P3750 diets (P<0.05), but there was not significantly different from that of fish fed the 50P4500, 55P3000, 55P3750 and 55P4500 diets. Protein efficiency ratio of fish fed the 45P3000 and 45P3750 diets was higher than that of fish fed 50P4500 and 55P4500, but there was not significantly different from that of fish fed the 45P3000, 45P3750, 45P4500, 50P3000, 50P3750, 55P3000 and 55P3750 diets. Based on weight gain, feed efficiency and specific growth rate, diets containing energy levels 4500 kcal/kg diet had an optimum P/E ratio of approximately 111 mg protein/kcal (50% crude protein) in juvenile river puffer.

• Journal of Fisheries and Marine Sciences Education
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• v.26 no.4
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• pp.859-867
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• 2014

This study was conducted to evaluate the optimum dietary lipid level in juvenile river puffer. Five semi-purified diets were formulated with corn oil to contain graded levels of lipid levels of 6, 9, 12, 15 and 18%. Fish averaging $8.32{\pm}0.02$ g randomly were fed the experimental diets in triplicate groups for 8 weeks. After the 8-weeks feeding trial, weight gain and specific growth rate of fish fed the 9% diet were significantly higher than those of fish fed the 15 and 18% diets (P<0.05) but there was not significantly different from that of fish fed the 6, 9 and 12% diets. Feed efficiency and protein efficiency ratio of fish fed the 6, 9 and 12% diets were significantly higher than those of fish fed the 18% diet (P<0.05). Visceralsomatic index of fish fed 18% diet was significantly higher than that of fish fed the 6% diet (P <0.05) but there was not significantly different from that of fish fed the 9, 12, 15 and 18% diets. No significant differences were observed in condition factor, hepatosomatic index and whole body composition among all the fish groups. Serum cholesterol and triglyceride fish fed of 18% diet were significantly higher than that of fish fed the other diets (P<0.05). Optimum dietary lipid levels by using broken-line model and by using second order polynomial were estimated at 7.01% and 8.98% for the maximum growth of fish respectively. Therefore, these results suggested that the optimum dietary lipid level could be greater than 7.01% but less than 8.98% for the maximum growth in juvenile river puffer.

• Journal of Fisheries and Marine Sciences Education
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• v.26 no.4
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• pp.915-922
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• 2014

This study was conducted to evaluate the optimum dietary protein level in juvenile river puffer. Five semi-purified diets were formulated by using casein to contain graded levels of protein levels of 35, 45, 50, 55 and 65%. Fish averaging $8.56{\pm}0.04g$ were randomly assigned to one of five experimental diets in triplicate groups for 8 weeks. After the 8-weeks of feeding trial, weight gain and feed efficiency of fish fed 45, 50 and 55% diets were significantly higher than those of fish fed 35 and 65% diets (P<0.05). Protein efficiency ratio of fish fed the 35% diet was significantly higher than those of fish fed 65% diet (P<0.05), but there were no significant difference among those of fish fed 45, 50 and 55% diets. Specific growth rate of fish fed 50% diet was significantly higher than those of fish fed 35 and 65% diets (P<0.05), but there was no significant difference among those of fish fed 45, 50 and 55% diets. No significant differences were observed in condition factor, hepatosomatic index, visceralsomatic index and survival among those of fish fed all the diets. Optimum dietary protein levels by using broken-line model and by using second order polynomial were estimated at 45.9% and 51.6% for the maximum growth of fish respectively. Therefore, these results suggested that the optimum dietary protein level could be greater than 45.9% but less than 51.6% for the maximum growth in juvenile river puffer.

• Journal of fish pathology
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• v.17 no.2
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• pp.99-103
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• 2004

White spot disease by Cryptocaryon irritans broke out among cultured river puffer (Takifugu obscurus) cultured in sea water in Oct. 2001 and May 2004. Many white spots were easily observed on the gills with the naked eyes. The parasites attached on the gills at the base of the gill lamellae. The trophonts penetrated the interlamellar epithelium. Epithelial cell proliferation in interlamellar spaces occurred. PAS- positive mucous cells were prominent in the proliferated epithelium.

• Journal of Fisheries and Marine Sciences Education
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• v.27 no.3
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• pp.718-724
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• 2015

To survey the most feeding frequence of formulated diet as food for cultured puffer in winter season, we performed a rearing test using juveniles of river puffer, Takifugu obscurus (body weight 15.0 g) for 120 days. The feeding frequencies were set up as 2times/1day, 2times/2days, 2times/3days and 2times/4days. We tested triplicately the experiment and investigated survival rate, daily food intake (DFI), feed efficiency (FE), condition factor (CF), daily growth rate (DGR). Consequently, growth was increased following to an increasing of feeding frequency, was the fast in 2times/1day of feeding frequency, and was the slowest in 2times/4days (p<0.05). DFI and CF were increased following to an decreasing of feeding frequency and was the highest in 2times/4days of feeding frequency. FE was decreased following to an decreasing of feeding frequency, and was the highest in 2times/1day of feeding frequency. In a proximate carcass composition at the final day, moisture and crude lipid contents were the lowest in 2times/4days, and in survival, there was not any significant difference among experimental groups. Therefore, we concluded that the 2times/2days are the best of feeding frequency for economical benefit of river puffer culture in winter season.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.54 no.1
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• pp.124-128
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• 2021

This study was conducted to evaluate the effects of incubation methods and transfer timings on the hatching rate of fertilized eggs of the river puffer Takifugu obscurus. Four incubation methods were tested, a) control (fertilized eggs attached to the glass plate), b) bottom (fertilized eggs spread on the bottom of the tank without any treatment), c) S-bottom (removing the stickiness of the fertilized eggs, and then spreading the eggs on the bottom of the tank), and d) incubator (removing the stickiness of the fertilized eggs, and then incubating the eggs in an incubator). Additionally, four transfer timings were tested: a) control (no transfer from the incubation tank), b) zygote (fertilized eggs transferred at the zygote stage), c) segmentation (fertilized eggs transferred at the segmentation stage), and d) pharygula (fertilized eggs transferred at the pharygula state). The results showed that the hatching rate of incubator was significantly higher than those of control, bottom, and glass (P<0.05). The results also showed that the hatching rates of control and pharygula were significantly higher than those of zygote and segmentation (P<0.05).

• Proceedings of the Korean Aquaculture Society Conference
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• 2006.05a
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• pp.467-469
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• 2006

• Journal of fish pathology
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• v.20 no.2
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• pp.129-137
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• 2007

Skeletal deformity in hatchery-reared river puffer (Takifugu obscurus) fingerlings occurred. The vertebral abnormality was recognized with naked eyes 80 days after hatching. Affected fish had a good appetite but no clinical signs were found except the vertebral abnormality. As more than 90% of the hatchery-reared fish exhibited vertebral abnormality, the fingerlings could not be used for commercial seeds any more. Morphological changes in the vertebrate and the swim bladder were observed with a soft X-ray. Histopathological changes on the caudal muscle around the deformed vertebrae, gill, and spleen were also examined to clarify the cause of the deformity. Spinal curvature occurred between vertebrae 10 and 12, but any malfunction of the swim bladder was not found. The diameters of the muscle fibers around the deformed vertebrae were much smaller and more irregular than those in normal fish, and the gabs between the fiber bundles were greatly enlarged. No evidence of inflammation response was found in the muscle layer. In the hatchery, feed was putting at the position of water inflow, which might attract the fingerings to move toward the feed in spite of incomplete development of their caudal muscle fibers. From these results, it is suggested that the high speed of water current in rearing aquaria might be associated with the development of vertebral abnormality.