• Proceedings of the Korean Aquaculture Society Conference
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• 2003.10a
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• pp.102-102
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• 2003

황복(Takifugus obscurus)은 주로 황해에 분포하며 봄철에 서해안으로 흐르는 금강, 한강 및 임진강으로 소상하여 강의 중상류에서 산란하는 소하성어류이다. 특히 황복은 바다와 하천을 오고 가는 관계로 해수뿐만 아니라 민물에서도 양식이 가능한 어종으로 다른 소하성어류와 마찬가지로 염분변화에 따른 삼투조절능력이 매우 우수할 것으로 생각된다. 본 연구는 황복이 급격히 염분을 달리하였을 때 나타나는 생리적 반응을 산소소비량과 암모니아 질소배설량의 변화로 염분변화에 따른 생리적 적응력을 살펴보고자 하였다. 본 연구에 사용한 황복은 전장 10cm(체중 15~25g) 전후의 치어로서 염분 32, 22, 12, 및 2 ppt로 조절되어 있는 FRP수조(500 L)에서 2개월간 사육 후, 각기 염분을 달리한(32, 22, 12, 2 ppt) 호흡측정 장치에 황복을 수용하여 산소소비량과 암모니아 질소배설량을 측정하였다. 한편, 사육 시스템내에서의 산소소비와 암모니아 질소의 배설경향을 보기 위하여 염분 16ppt에서 산소소비량과 암모니아 질소배설량을 25시간 관찰하였다. 산소소비 경향은 대체로 염분이 낮을수록 높은 산소소비 경향을 보였는데, 실험염분 32ppt에서는 2~32ppt 사육군 모두 다른 실험염분(22, 12, 2 ppt) 사육군보다 안정되고 낮은 산소소비량을 나타내었다. 그리고 실험염분 22, 12 및 2 ppt에서는 각기 실험염분과 동일한 염분 사육군에서 가장 높은 산소소비량을 나타낸 반면 32 ppt 사육군은 모든 실험염분에서 가장 낮은 산소소비량을 나타내었다. 암모니아 질소의 배설경향은 실험염분 2 ppt를 제외하고는 2 ppt 사육군에서 가장 높은 질소 배설율을 보였으나, 실험염분 2 ppt에서는 오히려 현저히 낮은 암모니아 질소 배설율을 나타내었다. 저 염분(2, 12 ppt)에서 사육한 황복은 22 및 32 ppt에서 사육된 황복에 비해 저염분에 노출될 경우 삼투조절을 위해 암모니아 배설에 상당한 차이를 보였다. 사육 시스템내에서 조사된 산소소비와 암모니아 질소 배설경향은 섭이와 관련하여 일간리듬을 보였는데, 산소소비는 섭이 3시간 후에 최고를 보였으며 암모니아 질소 배설은 섭이 4시간 후에 각각 최고를 나타내었다.

• Journal of Aquaculture
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• v.20 no.4
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• pp.270-277
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• 2007

White spot syndrome virus (WSSV) which is the most serious threat to cultured shrimp around the world has given enormous economic damages to shrimp culture industry every year since it was found from the shrimp ponds in the west coast of the South Korea in 1993. WSSV has strong infectivity as well as virulence and it can be rapidly transmitted among shrimps in ponds by cannibalism of infected ones. Polyculture of shrimps with carnivorous fish has been applied in commercial shrimp farms to suppress or delay the viral outbreak because the fish may selectively eat the moribund shrimps infected by virus. To determine the selective predatory effect of a carnivorous fish, river puffer Takifugu obscurus on white shrimp Litopenaeus vannamei, polyculture trials in laboratory scale of WSSV-infected and non-infected shrimps with river puffer were conducted in concrete round tanks of $28.26\;m^2$ in surface area as followings: 1) juvenile shrimps (B. W. 0.62 g) with 5 months old puffer (B. W. 11.60 g) cultured for 8 days, and 2) sub-adult shrimps (B. W. 6.84 g) with 16 months old puffer (B. W. 85.82 g) cultured for 5 days in order to know the effects according to size difference of cultured animals. In polyculture of juvenile shrimp with 5 months old puffer, survival rates of infected and non-infected shrimps were 46.0% and 89.1% respectively and in that of sub-adult shrimp with 16 months old puffer those were4% and 48% respectively. The results showed that puffer tends to selectively prey on virus infected shrimps among infected and non-infected ones in a limited space with although there is difference in predatory rate with age and density of animals. Regardless of different densities and ages of animals as well as health condition of shrimps, however, there were low differences in daily biomass of shrimp consumed per kg body weight of puffer. This finding suggests that puffer preys on healthy shrimps when moribund shrimps were not sufficient. Therefore, farmers should consider the total biomass of puffer as well as density and stocking time when they stock puffer into shrimp ponds for polyculture.

• Proceedings of the Korean Society of Developmental Biology Conference
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• 1998.07a
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• pp.68-69
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• 1998

정액의 ml당 정자수는 $1.13 \pm 0.34 \times 10^{10}$이었고 spermatocrit는 $64.8 \pm 1.4$였으며, 정장의 삼투질농도는 $266 \pm 2$ mOsm/kg이었다. 총 단백질 함량과 총 지질 함량은 정장에 비해 정자에서 높은 값을 보였고, glucose는 검출되지 않았다. 황복 정자를 16일간 $0 \pm 0.5 \circ C$에서 냉장보존 하였을 때, 수정률은 0-0.7%로 보존효과가 저조한 것으로 나타났다. 황복 정자의 냉동보존을 위한 희석액으로는 marine fish Ringer's solution, 동해방지제로는 5% DMSO가 적합하였으며, 이때의 수정률은 $79.3 \pm 7.5$%였다.

• 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.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.30 no.3
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• pp.408-412
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• 1997

The cytogenetic analysis of river puffer, Takifugu obscurus belongs to Family Tetraodontidae, was performed. The chromosome number of T. obscurus was 44 and the fundamental number was 64. Heteromorphic sex chromosomes were not found. The mean cellular size and nuclear size were $11.01\times7.95{\mu}m$ and $4.05\times3.15{\mu}m$, respectively. The mean surface area and volume in cell and nucleus were $68.76{\mu}m^2\;and\;366.00{\mu}m^3,\;10.06{\mu}m^2\;and\;21.36{\mu}m^3$, respectively. The number of erythrocyte of both female and male was $12\~13\times10^5/m\ell$. Gill tissues from diploid individuals had cells with one or two nucleoli. These cytogenetic studies should be used for cytotaxonomy and as a valuable estimation of polyploidy to come in T. obscurus.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.8 no.3
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• pp.237-242
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• 2003

Microstructure of otoliths and early growth in total length of laboratory-reared river puffer, Takrifugu obscurus were observed from 1 to 63 days after hatching. The total length of Takifugu obscurus was 3.09${\pm}$0.02 mm, 4.96${\pm}$0.24 mm, 5.39${\pm}$0.42 mm,9.13${\pm}$0.59 mm, 10.78${\pm}$0.96, 16.40${\pm}$2.31 mm, 30.49${\pm}$l.53 mm in 1, 10, 20, 30, 34, 43, 63 days respectively. The mean radius of otoliths was 14.20${\pm}$1.21 $\mu\textrm{m}$ in 1 day, 31.06${\pm}$2.31 $\mu\textrm{m}$ in 10 days,57.19${\pm}$6.19 $\mu\textrm{m}$ in 20 days,127.13${\pm}$13.13 $\mu\textrm{m}$ in 34 days,190.79${\pm}$17.08 $\mu\textrm{m}$ in 43 days and 281.85${\pm}$23.81 $\mu\textrm{m}$ in 63 days after hatching. Growth of otoliths were similar to the growth pattern in total length during 20-63 days after hatching. Hatch mark was distinguished with other growth increments and within a hatch mark two or three increments were observed. The number of growth increments was correlated with the days after hatching between 20 and 63 days after hatching.

• Journal of Aquaculture
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• v.12 no.1
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• pp.1-5
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• 1999

To obtain fundamental data for sperm cryopreservation in river puffer (Takifugu obscurus), the proper conditions of cryopreservation were investigated. In the sperm cryopreservation of river puffer, marine fish Rinser's solution (MFRS) was found to be good diluent and dimethyl sulfoxide (DMSO) was proved to be superior to glycerol as a cryoprotectant. The highest fertilization rate was achieved when river puffer sperms were cryopreserved with MFRS adding 5％ DMSO.

• 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.

• Proceedings of the Korean Society of Fisheries Technology Conference
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• 2000.10a
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• pp.231-232
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• 2000

자치어의 소화생리에 대한 연구는 담수어인 잉어, 무지개송어 등과 해산어인 넙치, 혹돔 등의 연구가 있으나 자치어 단계에 서식지의 변화가 큰 어종에 대한 연구는 전무한 실정이다. 따라서, 본 연구는 담수생활의 자어기에서 해수생활의 치어기로 전환하는 황복의 초기단계에 소화효소의 변화과정을 밝히고, 온도ㆍ염분ㆍ빛 등의 환경요인과 소화효소와의 관계를 조사하고자 한다. (중략)