• Korean Journal of Ecology and Environment
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• v.33 no.3 s.91
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• pp.282-294
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• 2000

The reproductive ecology and the early life history of Macropodus chinensis were investigated in aquarium. Mature male made the bubble nest and spawned with wrapping the female and reverse posture. The parental male protected the offspring until the larvae depart the bubble nest. Egg productivity and egg hatching rate were the highest at water temperature in $28^{\circ}C$ and $26^{\circ}C$ respectivity than any other artificial temperature. The eggs were buoyant, globular and 0.95${\sim}$1.05 mm in diameter. Cleavage was progressed at intervals of 15 minutes. Eggs hatched in 42${\sim}$44hours after fertilization and the newly hatched larvae were 3.0${\sim}$3.2 mm in total length. The lawae were 4.5${\sim}$5.4 mm in 4${\sim}$5 days after hatching and fed on the food with dispersion from the nest. In 40${\sim}$45 days after hatching, all fin rays completely developed, and juveniles reached 18.2${\sim}$23.5 mm in total length. In 90${\sim}$110 days after hatching, body from of young fishes were similar to adult with 37.4${\sim}$48.2 mm and represented secondary sexual characters longer than 45.0 mm in total length, and about 120 days, fishes began spawning(water temperature for ontogenesis: $26.0{\pm} 1^{\circ}C$).

• Journal of Life Science
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• v.20 no.12
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• pp.1902-1905
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• 2010

This study was conducted to increase the efficiency of farming practice in rainbow trout, Oncorhynchus mykiss, by sex reversal and chromosome-set manipulation techniques. Induction of sex-reversed gynogenetic diploid rainbow trout males and mass production of all-female rainbow trout by genetic sex reversal was performed. Phenotypic males in the gynogenetic diploid group were induced successfully by dietary administration of 5 mg of 17 alpha-methyltestosterone per kg diet for 82 days. All females were produced by crossing between normal female and sex-reversed gynogenetic diploid male rainbow trout.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.5 no.3
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• pp.233-237
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• 2000

The complete postembryonic development of nauplius stages of Paramphiascella vararensis T. Scotf (Copepoda: Harpacticoida) is described and illustrated based on specimens cultured in laboratory. The nauplii of P. vararensis feed on powder of a green algae, Ulva perusa. This species is metamorphosed to the stages of nauplius. Development from the nauplius stage to the nauplius stage take about 12 days under culture conditions of 33-34 ppt of salinity, 22-23$^{\circ}$C of temperature and feed on the algal powder. In the nauplius stages of P. vararensis, the rudiment of maxillule appeares at the third nauplius stage, and maxilla appeares at the fifth nauplius stage.

• The Korean Journal of Malacology
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• v.27 no.2
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• pp.143-148
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• 2011

Even though ark shell, Scapharca broughtonii is commercially important species, its artificial seed production is not yet fully developed. This study was carried out to understand the effect of three microalgal species on gonadal development and sex maturation of S. broughtonii in terms of broodstock management and food organism. Isochrysis galbana, Phaeodactylum tricornutum and Tetraselmis tetrathele were supplied to S. broughtonii broodstock in single or mixed. And condition index, gonadal development, sexual maturation and survival of the broodstock were analysed. After 45 rearing days, frequency of ripe stage of gonadal phases, rate of induced sexual maturation and survival of S. broughtonii broodstock fed mixed diet with 3 microalgal species or single diet of T. tetrathele were the highest.

• Journal of fish pathology
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• v.37 no.1
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• pp.79-88
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• 2024

Aeromonas spp. infections have been reported to cause significant economic losses not only in the ornamental fish industry but also in aquaculture. In December 2022-January 2023, an Aeromonas infection occurred on a goldfish in korea, A gram-negative bacterium was isolated from the skin and internal organs of infected goldfish (Carassius auratus). The results showed that the isolate was identified as Aeromonas veronii using 16S rDNA targeted oilgpnucleotide primers, furthermore characteristics of A. veronii was confirmed by enterotoxin gene, infectious experiment, antibiotic resistance. In-vivo pathogenicity of isolates to goldfsh resulted in 100% mortality in challenged host within one week of post experiment injection. As a result of PCR analysis targeting three enterotoxin-encoding genes, cytotoxic enterotoxin (act) was identified in A. veronii isolate in this study. Antimicrobial susceptibility pattern of isolate showed it was to susceptible to most antimicrobial agents tested but resistant to ampicillin, imipenem, meropenem and clindamycin.

• The Korean Journal of Malacology
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• v.25 no.2
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• pp.105-112
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• 2009

We investigated the degree of obesity, histological development stages of gonads and sexual maturation induction rates of comb pen shell, Atrina pectinata, per the type of micro-algae supplied. Terms of maturation by singular or mixed supply of microalgae, it was found that maturation of the female was the quickest at 60.0% by the Tetraselmis tetrathele (Tet). experiment group followed by 57.1% by the Chlorella ellipsoidea (Chl). experiment group and 16.7% by the Phaeodactylum tricornutum (Pha). experiment group. However, there were no significant differences between Tet. experiment group and Chl. experiment group. As for the male, maturation was the quickest at 60.0% by the Tet. experiment group followed by 16.7% by the Chl. experiment group and 14.3% by the Pha. experiment group. In light of these results, Tet. is concluded to be a very useful feed organism in breeding the mother comb pen shells. Upon completion of the experiment, the sexual maturation induction rate for the female was found to be the highest at 82.0% in the Tet. experiment group followed by 72.0% by the Chl. experiment group, 64.0% by the Pha. experiment group and 58.0% by the mixed micro-algae experiment group. During the period of experiment, the survival rate was the highest at 94.4% by the mixed micro-algae experiment group followed by 90.0% by the Pha. experiment group, 83.1% by the Tet. experiment group and 78.8% by the Chl. experiment group.

• Journal of Aquaculture
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• v.11 no.4
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• pp.529-546
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• 1998

Gonadal part that developed by indifferentiation period for 6 months after hatching is made as gonad and fat body. These gonad are thin semi-transparant and undistinguished germ cell. Germinal epithelium is distinguished by development of gonad epithelial tissue from 7 months after hatching. Sex differentiation is begun by oogonia develoment at 8 months after hatching. Primary oocytes grow over germinal epithelium of gonadal cavity, at 9 months after hatching, gonadal cavity become ovarian cavity as they increasing. As soon as oocytes at 13 months after hatching are filled with the whole part of gonad, degeneration of oocyte is begun. And then, gonad has cavity tissue, a small number of oocyte are located in gonadal cavity. At 15 months after hatching, new primary oocyte develop and cavity of ovarian tissue in the central of ovarian cavity. Spermatogonia multiplicate and cavity tissue consist of testicular tissue. These gonad become hermaphrodite and then ditermine the sex of female and male. These results show the red sea bream is juvenile hermaphrodite and undif-ferentiated gonochoristic teleost. Male and female differentiation type of gonad is divided in undifferentiation stage, oogonia-like stage, ovary-like stage, ovary development stage, hermaphroditic testis stage, hermaphroditic ovary stage, and testis development stage. Undifferentiation stage is continued total lenth 18cm at 13 months after hatching. ovary-like stage is continued total length 11~18cm at 13 months after hatching. Ovary-like stage is continued total length 14~26cm at 10~14 months after hatching. Ovary development stage begins from total length 20cm, 14 months after hatching. At 20 months after hatching, 44 percent of total sampled individuals had ovary. Hermaphroditic ovary stage first begins total length 19~20 cm at 15 months after hatching, but it is not observed total length 28~29cm at 20months after hatching. Hermaphroditic testis stage first begins total length 21~22cm at 20months after hatching and is continued for 20months. Testis development stage first begins total length 20~21cm at 20 months after hatching, and is occupied 33 percent total length 28~29cm at 20 months. The beginning of sex differentiation more than 50 percent is from total length 16cm at 11 months after hatching. Sex determination begins total length 20cm, 14months after hatching in female and total length 20cm, 15 months after hatching in male. Sex determination more than 50 percent begins total length 23cm,, 17 months after hatching. Undifferentiated gonadal part of red sea bream consist gonad and fat body. As differentiation is going on and gonad is growing, fat body shrinks. This appearence is showed the same tendency in 3-year old red sea bream. 1.9mm larvae after hatching grow about 19mm larvae for 47 days. The relationship between the total length and body weight of larvae and juveniles in $BW=4.45{\times}10^{-6}TL^{3.4718}$ r=0.9820. Fishes in cage culture grow to maximum total length 28.4cm. The relationship between the total length and body weight of these fishes is $BW=2.36{\times}10^{-2}TL^{2.9180}$, r=0.9971. Undifferentiated gonadal part of red sea bream consist gonad and fat body. As differentiation is going on and gonad is growing, fat body shrinks.

• Korean Deer Journal
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• v.8 no.6 s.54
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• pp.153-157
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• 2003

농림부가 올해 12월27일부터 개정될 축산법 시행령, 시행규칙 개정령(안) 중에서 개량대상 축종에 오리와 개가 신규 포함된 반면, 사슴이 빠져 있어 논란이 예상되고 있다. 본회 김수근 회장은 '사슴은 이미 사육가구수와 마리수에서 소, 돼지, 닭에 이어 4대 축종에 거론될 만큼 상당한 규모를 자랑하는데 이번 축산법 개정에서조차 개량대상 축종에서 제외된다는 것은 말도 안되는 불합리한 처사'라 반발하며 사슴도 축산법상 정식 개량대상 축종에 포함될 수 있도록 조치를 취해달라고 주장했다. 이에 대해 농림부 해당부서 관계자는 '사슴이 개량대상 축종에 포함되어야 한다는 요지의 공문과 자료를 관계부서에 제출하면 심의를 거쳐 대상 여부를 결정짓겠다'고 밝혔다. 이에 본회에서는 공문을 통해 농림부 해당부서에 '축산법 시행규칙에서 정하는 개량대상 가축에 사슴이 제외되어 있어 체계적인 개량사업 추진에 차질이 예상된다'고 밝히고 사슴을 정식 개량대상 축종에 포함시켜달라고 건의했다. 한편 농협중앙회는 '농림부 축산법 개정안에서 사슴이 개량대상 축종에 포함되지 않은 것은 뜻밖의 일'라고 밝히고 농협중앙회 차원에서도 사슴이 개량대상 축종에 포함될 수 있도록 농림부에 건의키로 했다. 농협중앙회 역시 타당성 근거를 위해 본회에 사슴 개량에 관련된 자료를 요청했으며 본회에서는 즉시 농협중앙회측에 자료를 발송했다. 아래는 본회가 농림부에 보낸 공문 및 사슴 개량 관련 자료.

• Journal of the korean veterinary medical association
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• v.46 no.5
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• pp.402-412
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• 2010

지난 1월 7일 경기도 포천지역에서 구제역발생에 이후 성공적인 차단방역으로 구제역 종식선언을 한지 16일만인 4월 8일 강화도에서 또 다시 2차 발생으로 차단방역에 총력을 기울이고 있던 중, 4월 22일 충북 충주지역에서 구제역발생이 확인됨에 따라 소, 돼지 등 사육농가들과 방역당국은 총체적인 차단방역활동을 기울이고 있다. 이는 국내 축산업계의 막대한 손실뿐만 아니라 관련 산업에 지대한 영향을 미치고 있어, 조속한 시일내에 구제역 확산 차단에 국가 및 지방의 방역당국과 관련 종사들이 불철주야 노력을 기울이지 않으면 아니된다. 따라서 구제역 등 전염병의 발생 차단을 위해서는 무엇보다도 축사 입구, 내외 부 및 이동도로의 철저한 소독과 방역활동이 중요하며, 축산농가들의 방역의식고취가 시급하다 하겠다. 이웃나라인 일본에서도 지난 4월 20일 미야자키현의 화우 번식우 농장에서 구제역이 10년만에 발생되어 확산을 차단하기 위한 방역활동을 펼치고 있다. 또한 마지막으로는 필자가 작년 10월과 금년 1월 하순에 일본 오끼나와현과 미야자키현(주 : 일본 수의사회 주최, 한-일공동산업동물 국제심포지엄, 국내 구제역 발생으로 한국우병학회 회원들은 실제 불참하였으며, 연자만 참석하였음)에 갈 기회가 있었는 바, 일본측에서 요구한 서약서 및 방역대응요령에 대해서의 수칙을 요구한 바가 있어 참고로 번역하여 소개한다.

• The Korean Journal of Zoology
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• v.38 no.4
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• pp.465-482
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• 1995

The 7 zoeal and 1 megalopal stages of Cha~bdi8 bimaculata (Miers, 1886) are descrihed and iflustrated in detail from larvae reared in lahoratory. Under isboratory conditions of 22$^{\circ}C$ temperature and 33.3~ salinity, the magalopa was attained in 32 days or more after hatching. The larval morphology of the first zoea of C. bimaculata are coincide with those of Charybdis species by hearing lateral spines on carapace, ~type antenna, A-type telson, 1,6 setae on the endoped of maxillule, and 6 setae on the endopod of maxilla. Morphological features of C. bimaculata larvae were compared to the previous descriptions of larvae of the other spedes helonging to the same genus.