• 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.28 no.2
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• pp.137-140
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• 1995

The pufferfish Takifugu obscurus (hwang-bok) was examined for toxicity. Forty-six specimens, which had Gaught at the Imjin River in 1992 and 1993, Korea, were collected and assayed for anatomical distribution of toxicity by the mouse assay method. Ovary and liver showed very strong toxicity, testis, intestine, gall bladder and spleen did moderate toxicity, muscles and skin did weak toxicity, and blood was non-toxic. The results of this study were different from those of Tani, who had examined the toxicity in 19 species of pufferfish, in terms of toxicity in testis, muscle, and skin. The toxicity of testis and muscle had been known to be non-toxic or weakly toxic previously, however, they were known to have weak or moderate toxicity. Therefore, careful attention should be taken to prevent food poisoning by pufferfish ingestion.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.47 no.4
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• pp.383-389
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• 2014

An 8-week feeding trial was conducted to determine the apparent dry matter and protein digestibility of seven different dietary protein sources by juvenile river puffer Takifugu obscurus. Eight diets containing white fish meal (WFM), brown fish meal (BFM), squid liver powder (SLP), krill meal (KM), leather meal (LM), soybean meal (SM), or fermented soybean meal (FSM) were prepared by mixing a basal diet (BD) with one of the seven test ingredients at a ratio of 7 to 3. Fish averaging $10.8{\pm}0.04g$ were fed the experimental diets in triplicate groups. The apparent dry matter digestibilities of BFM, WFM, FSM, SLP, LM, SM, and KM were 80, 78, 72, 67, 56, 55, and 54%, respectively, while the corresponding apparent protein digestibilities were 96, 96, 93, 92, 89, 88, and 86. The weight gain of fish fed BFM was significantly greater than that of fish fed SM or LM (P<0.05), while it was not significantly different from that of fish fed the BD, WFM, FSM, BFM, SLP, or KM. These results indicated that WFM, BFM, FSM, and SLP are potentially good protein sources for replacing fish meal in river puffer feed.

• 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).

• Korean Journal of Fisheries and Aquatic Sciences
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• v.53 no.6
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• pp.878-885
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• 2020

Previously, we reported that globefish Takifugu obscurus homogenate suppresses the growth of human colorectal cancer cells. To extend the applications of globefish homogenate, we investigated its cytotoxic effects on human breast cancer cells. To assess the effects of globefish homogenate on growth of MCF (Michigan Cancer Foundation)-7 human breast cancer cells, cell proliferation and colony formation assays were performed using the cell counting and Crystal Violet staining methods. The 50% inhibitory concentration (IC50) of globefish homogenate on MCF-7 cell proliferation was calculated from the sigmoidal dose-response curve. The colony formation assay demonstrated that MCF-7 cells treated with globefish homogenate formed up to 80% fewer colonies than control MCF-7 cells. Treatment with globefish homogenate markedly suppressed the growth of MCF-7 cells in a dose-dependent manner. The sensitivity of the cells to globefish homogenate was determined by calculating the IC50; in this case, the IC50 was 210 ㎍/mL. Furthermore, significant downregulation of Cyclin D1 expression, along with phospho-Akt and total Akt levels, was observed in MCF-7 cells treated with globefish homogenate. This study demonstrates that treatment with globefish homogenate inhibits the proliferation of MCF-7 human breast cancer cells by downregulating the expression of phosphor-Akt, total Akt, and Cyclin D1 proteins.

• Journal of Aquaculture
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• v.21 no.4
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• pp.331-338
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• 2008

Monthly changes in the gonadosomatic index (GSI) and hepatosomatic index (HSI) of wild river puffer Takifugu obscurus, and water quality environment in spawning area during breeding season were investigated from March 1995 to February 1996. Monthly changes in GSI and HSI of T. obscurus, that was cultured in low salinity, were calculated. The external morphology of the gonads, germ cell differentiation during gametogenesis and the reproductive cycle with the gonad developmental phases were investigated by histological analysis. The optimum water quality environment in Ganggyung, Choongcheongnam-do, where is spawning ground of wild T. obscurus, was $15-20^{\circ}C$ (water temperature) and 0 psu (salinity). Monthly changes in the GSI in females and males reached a maximum in May, and then rapidly decreased. Therefore, it is assumed that in the natural condition the spawning period of wild T. obscurus is May to June. In females and males, it showed a negative correlationship between the GSI and HSI. The external morphology of the gonads in female and male T. obscurus, that was cultured in low salinity, is composed of a pair of saccular structure. Based on monthly changes in the GSI, it is assumed that in female T. obscurus, that was cultured in low salinity, spawn from March through May. Therefore, it showed a negative correlationship between changes in the GSI and HSI. On the whole, in females and males, it showed a similar pattern between wild and cultured T. obscurus. The reproductive cycle with the gonad developmental phases can be classified into successive five stages in females: the early growing stage, late growing stage, mature stage, ripe and spent stage, and recovery and resting stage. In males, that can be divided into successive four stages: the growing stage, mature stage, ripe and spent stage, and recovery and resting stage. In case of wild T. obscurus, the spawning period has once a year, however, those cultured in the high water temperature ($20-27^{\circ}C$) - low salinity (under 3.3 psu) condition have reproductive characteristics having possibilities of discharge of eggs and sperms year-round as a multiple spawner.

• Korean Journal of Ichthyology
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• v.35 no.2
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• pp.67-74
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• 2023

The river pufferfish (Takifugu obscurus) is a valuable species in aquaculture and genetic studies. Usage of fish anesthetics aids in the easier handling of fish during aquaculture. However, there are no studies on appropriate conditions required for effective anesthetization of pufferfish. This study aims to determine the optimal conditions (fish age, water temperature, anesthetic concentration) needed for the most common fish anesthesia, MS-222, to anesthetize T. obscurus. We tested three different water temperatures (20℃, 24℃, and 28℃), three different anesthetic concentrations (125 mg/L, 150 mg/L, and 175 mg/L), and two different fish ages (one- and two-year-old). Appropriate anesthetization conditions for T. obscurus ranged from 150 mg/L to 175 mg/L of MS-222 at 24℃ to 28℃ for one-year-old fish. For two-year-old fish, the appropriate conditions ranged from 150 mg/L to 175 mg/L of MS-222 at 28℃. However, to minimize side effects and risks, 150 mg/L of MS-222 at 24℃ for one-year-old fish and 175 mg/L of MS-222 at 28℃ for two-year-old fish are recommended for effective anesthetization.

• Environmental Analysis Health and Toxicology
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• v.19 no.2
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• pp.141-151
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• 2004

We exposed juvenile puffer fish, Takifugu obscurus(30 days after hatching) to various aqueous pollutants including 4 kinds of inorganic metals (Ag, Cd, Cu and Hg), 2 organotin compound.; (tributyltin ［TBT］ and triphenyltin［TPhT］) and 5 polycyclic aromatic hydrocarbon (PAH) compounds (chrysene, fluoranthene, naphthalene, phenanthrene and pyrene) to estimate median lethal concentrations (LC50s) of each pollutant after the 96-hour acute exposure. Among the inorganic metals, Hg (52 $\mu\textrm{g}$/L; 96-h LC50) was most toxic to test animals and followed by Ag (164 $\mu\textrm{g}$/L), Cu (440 $\mu\textrm{g}$/L) and Cd (1180 $\mu\textrm{g}$/L). Aqueous TBT was more toxic between the two organotins; the 96-h LC50 for TBT (5.1 $\mu\textrm{g}$/L) was 3 times lower than that of TPhT (17.3 $\mu\textrm{g}$/L). The acute toxicity of PAH compounds was highest for chrysene (1.5 $\mu\textrm{g}$/L; 96-h LC50) and decreased in the order of pyrene (65 $\mu\textrm{g}$/L) > fluoranthene (158 $\mu\textrm{g}$/L) > phenanthrene (432 $\mu\textrm{g}$/L) > naphthalene (8690 $\mu\textrm{g}$/L). The toxicity of PAH compounds wat closely related to their physico-chemical characteristics such as $K_{ow}$ and water solubility, and well explained by simple QSAR relationship. The sensitivity of puffer fish to various inorganic and organic pollutants was generally comparable to various fish species widely used as standard test species in previous studies and further evaluation should be conducted to develop adequate testing procedure for T. obscurus when used in various toxicity tests.

• Proceedings of the Korean Society of Fisheries Technology Conference
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• 2002.05a
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• pp.439-440
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• 2002

• Proceedings of the Korean Society of Fisheries Technology Conference
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• 2002.05a
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• pp.437-438
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• 2002