• 한국어류학회지
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• 제33권2호
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• pp.57-63
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• 2021

본 연구는 경북 낙동강에 서식하는 떡붕어의 초기생활사를 관찰하여 근연종과 차이점을 확인하기 위해 분류학적 기초자료를 확보하고자 하였다. 떡붕어 암컷의 산란량은 30,400~44,900개(37,650±7,250개) 정도였다. 난의 형태는 원형으로 크기는 1.24~1.37 mm (1.31±0.04 mm, n=30)였다. 수정란은 수온 21℃에서 부화까지 110시간이 소요되었다. 부화 직후의 난황자어는 전장 4.69~5.65 mm (5.15±0.31 mm, n=10)로 입과 항문은 열려있지 않았고 난황을 가지고 있었다. 부화 후 3일째 전기자어는 전장 6.27~6.70 mm (6.59±0.08 mm, n=10)로 난황 흡수가 완료되면서 먹이를 섭취하였다. 부화 후 10일째 후기자어는 전장 8.71~8.92 mm (8.81±0.07 mm, n=10)로 꼬리지느러미 말단 끝부분이 45°로 휘어졌다. 부화 후 42일째는 전장 15.1~16.8 mm (15.8±0.57 mm, n=10) 각 부위별 지느러미 기조 수(등지느러미 iii17개, 뒷지느러미 iii4개)가 정수로 도달하면서 치어기로 이행하였다.

• International Journal of Industrial Entomology and Biomaterials
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• 제18권1호
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• pp.1-7
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• 2009

Quality of seed in the mulberry silkworm, Bombyx mori (L.) is determined by many important factors, wherein unfertilized eggs play an important role. Unfertilization of eggs are caused by several reasons such as, abnormality in the sexual organs of the male and female, abnormal development of the micropylar end of the egg, unfavorable environmental conditions during spinning, cocoon preservation, imperfect handling of moths, mating, ovipostion, cold storing of pupae / moths and indiscriminate use of male moths etc. Though the presence of unfertilized eggs would in no way affect the fertilized ones and their quality directly, the frequency of their occurrence underrates the quality and brings down the hatching percentage. Lower the occurrence of unfertilized eggs, higher is the rating of seed quality. Of the various intrinsic and extrinsic factors and events involved in egg deposition of an adult silk moth, mating is an instinct and a biological obligation for the ultimate perpetuation of the species and a must to provide stimulus for oogenesis and bring about biochemical changes in the spermatophore of the silkworm in order to ensure the presence of sufficient number of normal sperms and testicular fluid in the female reproductive organ, activating ovulation and accelerating oviposition behavior and egg deposition. An attempt has been made in this article to briefly elucidate the characteristics of unfertilized eggs, causes of their occurrence and its impact as well as the significance in silkworm seed production.

• 한국발생생물학회지:발생과생식
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• 제19권4호
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• pp.189-196
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• 2015

This study was examined the ovogenesis of Ussurian bullhead, Leiocassis ussuriensis and the morphological development of its larvae and juveniles and to use the results as basic information for the preservation of species and resource enhancement. For artificial egg collection, human chorionic gonadotropin (HCG) was injected at a rate of 10 IU per gram of fish weight. During breeding period, water temperature maintained at $24.5{\sim}26.5^{\circ}C$ (mean $25.0{\pm}0.05^{\circ}C$). The process of ovogenesis reached the two-cell stage in 50 minutes after fertilization. In 73 hours of fertilization the movement of the embryoid body became active state and the larvae began to hatch from the tail through the oolemma. Length of prelarvae were 6.33~6.50 mm long (mean $6.40{\pm}0.06mm$) just after hatching having yolk with their mouth not opened. After thirty eight days of hatching, juveniles were 30.6~32.5 mm long (mean $31.5{\pm}0.65mm$). The color was dark yellowish brown throughout the entire body, and the number of caudal fin rays developed to thirty six perfectly.

• The Korean Journal of Ecology
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• 제16권2호
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• pp.155-157
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• 1993

The life-cycle and seasonal abundance of Anaulaciulus koreanus koreanus was studied at Hwang-dong, Chonbuk Province, Korea from October 1990 to February 1992. The egg hatches in spring and the pupoid stage is passed through within the egg shell. The juvenile develops as far as stadium IX by the third year following the birth. Pairing and oviposition take place in the fourth year spring when females are at stadium XI. They seem to live one or two years more after egg-laying. Anamorphosis was observed in this species. Abundance of A. koreanus koreSanus increases from April to May when there appears thefirst peak. It fals gradualy thereafter and the species spends summer months underground from July to September. The second peak appears in October and the activity decreases again in November getting ready to overwinter. The first peak arises from a large number of individuals of 2 and 3 year old overwintered plus newly hatched spring juveniles, and the second from 1 to 3 years old wanderings. Inactivity observed in the species during summer and winter seasons appears to be a temporal due to the extreme temperatures.

• Parasites, Hosts and Diseases
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• 제22권2호
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• pp.203-208
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• 1984

만손주혈흠충 충란의 soluble eff antigen (SEA)을 mini-pump를 이용하여 마우스, 복강내에 지속적으로 주입시키면서 말초혈액내의 호산구수 변동, delayed hypersensitivity인 ear swelling test, 간조직병변, 효소 표식면역법을 이용한 혈청내 항체가를 경시적으로 관찰한 결과 다음 성적을 얻었다. 1. 말초혈액 호산구수는 SEA투여후 2~3주후에 최고에 달하였고 그후 서서히 감소하였다. 2. Ear swelling test 실시에서 SEA투여 2주후에 종창이 최고에 달하고 그후 서서히 감소하였다. 3. 간조직병변은 SEA투여후 4주에 육아종형성을 관찰하였고 그후 조직손상이 복귀하였다. 4. 현청에서의 항체가는 SEA투여후 4주후에 양성대조군보다 높았으며 시간이 경과함에 따라 항채가가 증가하였다.

• Fisheries and Aquatic Sciences
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• 제3권3_4호
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• pp.180-187
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• 2000

Reproductive effort and spawning frequency of the two palaemonid prawns, Exopalaemon modestus and Palaemon gravieri, were investigated. In both embryos of the two species, egg size was larger in E. modestus than in P. gravien but for a given size, number of eggs (EN) was fewer in E. modestus. The statistical results revealed that there were significant differences in egg size and EN between the two species. E. modestus living in freshwater environments had larger and fewer offspring than P. gravieri inhabiting marine environments. These findings are consistent with predictions from r- and K-selections models. Reproductive effort (RE) also was higher in E. modestus, suggesting the possibility for E. modestus to invest larger amount of energy per individual offspring. In the two prawns the ovarian dry weight of females with eyed eggs was significantly higher than those with non-eyed eggs. This indicates that the ovarian maturation occurs during the period between the two embryonic stages, suggesting females being potentially of continuous breeding within a single reproductive period. In the both species brood loss did not occur during the incubation period.

• 한국응용곤충학회지
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• 제37권2호
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• pp.159-162
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• 1998

온도가 벼잎벌레의 산란 및 발육에 미치는 영향을 조사하였다. 조사온도는 15, 20, 23, 25, $28^{\circ}C$로 하여 수행한 결과 발육기간은 $15^{\circ}C$에서 $28^{\circ}C$에서 최고를 이루고 다시 낮아지는 경향을 보였다. 발육기간은 저온보다 고온($28^{\circ}C$)에서 짧은 경향을 보였다. 알발육영점도는 $6.4^{\circ}C$, 총유효적산온도는 75.8일도였다. 이 결과는 $23^{\circ}C$가 벼잎벌레의 산락적온으로 추정되었다.

• 한국수산과학회지
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• 제54권1호
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• pp.31-37
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• 2021

The mass production of fertilized eggs of the convict grouper Hyporthodus septemfasciatus was studied from 2013 to 2020 for industrial aquaculture. The experiment was divided into two groups. Group 1 broodstock was raised from wild-caught fry and used from 2013 to 2020. Group 2 broodstock was raised from artificially propagated fry and used from 2019 to 2020. Males used to collect sperm for artificial insemination weighed more than 7 kg. The effects of various hormones on artificial ovulation were investigated from 2013 onward. Among these, luteinizing hormone-releasing hormone analogue (LHRHa) at 100 ㎍/kg body weight showed the most effective results and was used for artificial egg collection from 2014 onward. In Group 1, the average total egg production per year, average egg production per individual, fertilization rate, and hatching rate were 26,143 mL, 609.7 mL, 93.3%, and 91.8%, respectively, and in Group 2, were 2,750 mL, 316.5 mL, 92.1%, and 90.4%, respectively. Based on these results, we showed that a large number of fertilized eggs for artificial seeding could be produced consistently. Moreover, the mass production of fertilized eggs in Group 2 establishes a foundation for the complete aquaculture cycle of H. septemfasciatus.

• Asian-Australasian Journal of Animal Sciences
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• 제18권1호
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• pp.8-12
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• 2005

Response in a modified reciprocal recurrent selection scheme for egg production was evaluated considering variable family sizes and genetic correlation between purebred and crossbred half sisters. The criteria of selection of purebred breeders included pullet's own performance, purebred full and half sisters and crossbred half sister's performance. Heritability of egg production of crossbreds (aggregate genotype) and purebred's was assumed to be 0.2 and genetic correlation between purebred and crossbred half sisters ($r_{pc}$) as 0.1, 0.2, 0.3, 0.4, 0.5, 1.0, -0.1, -0.2, -0.3, -0.4, -0.5 and -1.0. Number of dams per sire to produce purebred and crossbred progenies assumed to be 5, 6, 7, 8, while number of purebred female progeny ($N_p$) and crossbred progeny ($N_c$) per dam were considered to be 3, 4, 5 and 6 in each case. Considering phenotypic variance as unity, selection indices were constructed for different combinations of dams and progeny for each value of $r_{pc}$. Following selection index theory, response in crossbred and purebred for egg production was computed. Results indicated that response in crossbreds depended mainly on crossbred family size and also on magnitude of$r_{pc}$ irrespective of its direction, and response was greater with large crossbred family size than the purebred families. Correlated response in purebreds depends both on magnitude and direction of $r_{pc}$ and was expected to be greater with large purebred family size only. Inclusion of purebred information increased the accuracy of selection for crossbred response for higher magnitude of$r_{pc}$ irrespective of its direction. Present results indicate that desirable response in both crossbred and purebred performance is a function of $r_{pc}$ and family sizes. The ratio of crossbred and purebred family sizes can be optimized depending on the objective of improving the performance of crossbreds and/or of purebreds.

• 한국가금학회지
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• 제41권1호
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• pp.69-75
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• 2014

본 시험은 토종 실용오리를 생산하기 위한 토종 오리 A와 B 계통의 산란기 성적을 조사하기 위하여 수행하였다. 2계통의 토종 오리들은 계통 당 6반복, 반복당 14수씩 총 168수를 선별하여 산란기의 성적을 조사하였다. 사료는 산란오리 사료(CP 15%, ME 2,900 kcal/kg)를 20주령부터 80주령까지 급여하였다. 체중은 A와 B 계통 사이에서 유의적인 차이가 없었다. 주령별 체중을 보면 40주령부터 48주령까지의 체중이 가장 낮게 나타났으며, 24~32주령, 64~80주령에서는 체중이 유의적으로 높게 나타났다(P<0.05). 사료 섭취량은 체중과 마찬가지로 A와 B 계통 사이에서 유의적인 차이가 없었다. 주령별 사료 섭취량은 36~48주령, 68~72주령에 유의적으로 감소하였으며, 52~56주령에 사료 섭취량이 가장 높았다(P<0.05). 계통별 평균 난중은 A와 B 계통 사이에서 유의적인 차이를 보이지 않았다. 주령별 평균 난중은 32~40주령에서 낮게 나타났다. 산란율은 24~28주령, 60~64주령 및 20~80주령에 B 계통에서 A 계통에 비해 높게 나타났다(P<0.05). 주령별 산란율은 28주령에서 최고로 높아져 48주령까지 높은 산란율을 나타냈으며, 52주령부터 감소한 후 68주령에는 다시 산란율이 회복되기 시작하였다(P<0.05). 산란 수는 전반적으로 A 계통에 비해 B 계통이 높게 나타났으나, 산란율이 급상승하는 시기인 28주령부터 48주령까지는 A와 B 계통 사이에서 유의적인 차이가 없었다. 주령별 산란 수는 주령이 경과함에 따라 유의적으로 증가하였다. 전반적인 사료 요구율은 A 계통이 B 계통에 비해 높게 나타났다(P<0.05). 그러나 28~36주령에는 A와 B 계통의 사료 요구율은 유의적인 차이가 없었다. 이런 결과들은 토종 종오리의 산란기 성적에 대한 기초적인 자료로서 이용될 것이라 사료된다.