• International Journal of Industrial Entomology and Biomaterials
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• 제10권1호
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• pp.19-24
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• 2005

Nutrition is very essential for growth, development and reproduction. The quantitative impetus of nutritional factor on adult characters and reproductive fitness was studied in Antheraea mylitta by providing fresh leaves of Terminalia tomentosa for 1 to 4 times a day to $5^{th}$ instar larvae. All the characters have improved on giving fresh diet more times over the single diet. The adult weight has strong effect on the reproductive potential i.e., female pupa and moth weight, survivability, pupation rate, emergence percentage, fecundity, fertility, egg weight and hatched out larval weight. The improvement recorded to the tune of $70\%,\;77.1\%,\;115.4\%,\;36.7\%,\;45.9\%\;and\;218.3\%$ in larval weight gain, survivability, pupation rate, female pupa weight, moth weight and fecundity respectively when fresh diets were provided 4 times a day against single diet. The adult emergence percentage has increased from $66.4\%\;to\;96.2\%$ and fertility rose from $52.2\%\;to\;93.6\%$. The weight of eggs and the larvae hatched out of it also found to be significantly higher in 4 diets a day condition. The study revealed that optimization of fresh diet frequency should be maintained to obtain higher egg production and fertility in order to get vigorous larvae to continue the generation.

• 한국해양학회지
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• 제22권4호
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• pp.236-245
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• 1987

천수만에서 금강 하구에 이르는 13개 정점에서 1985년 7월부터 1986년 6월에 걸쳐 부유성 난과 자치어를 채집하였는데, 이중 부유성 난은 19개 분류군으로, 자치어는 8 月 28 科에 속하는 45개 분류군으로 동정 되었다. 본 연구에서는 부유성난과 자치어의 동정을 위한 검색표 작성의 일환으로 부유성난에 대해서는 유구의 수, 난의 형태, 난막의 돌기, 난경, 유구경 등의 형질에 따라 19개 분류군의 검색표를 작성하였으며, 자치어에 대해서는 體形, 肛門의 위치 色素胞의 배열 등의 형태적인 형질에 따라 우선 科 수준의 檢索表를 작성하였다.

• 한국발생생물학회지:발생과생식
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• 제24권1호
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• pp.63-70
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• 2020

This study aimed to investigate early life of Coreoperca herzi living in Han River and compare morphological differences between different groups during the development in order to provide basic data for relevant taxonomic research. On average, one female individual spawned 541 to 861 eggs (average 701) at once. After 259 hours, the tail broke out of the egg membrane and hatching began. Immediately after hatching, the larvae were average 7.81±0.10 mm (n=5) in total length. 60 days the juvenile was average 35.9±1.30 mm (n=5) in total length. The white spots spread to the rest of the body, rending the same pattern as that on the body of their broodstock fish.

• 한국패류학회지
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• 제1권1호
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• pp.5-12
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• 1985

The maturity of gonads, early development of the fertilized egg, spawning period, and morphogenesis of larvae in Limnoperua fortunei were studied from October, 1981 to November, 1982 as on attempt to identify its life cycle. 1) Active motility of its sperm was observed at late May, and matured egg could be found at late June. 2) It was estimated that the spawning was occured from late August. This species was belong to the short-term breeder because it finished its spawning within 20 days. 3) It has free-living trochophore and D-shaped larva stage. The shell lengths of early, middle, and D-larval stage were $140.0{\mu}m$, $167.6{\mu}m$ and $210.0{\mu}m$, respectively. The shell heigths of each stage were $97.3{\mu}m$, $137.6{\mu}m$ and $178.2{\mu}m$, respectively.

• 한국발생생물학회지:발생과생식
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• 제18권3호
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• pp.173-178
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• 2014

In order to monitor the developmental features of embryos, larvae, and juveniles of Oryzias latipes (Temminck and Schlegel), Oryzias latipes was caught in river of Shinduck-dong, Yeosu-si, Jeollanam-do, on May 2011, and experiments were carried out in Ichthyology laboratory at Chonnam National University. The blastodisc step was the first level for natural spawning. The optic vesicle, Kupffer's vesicle, myotome began to appear 75 hours 57 minutes later. After blastodisc development, the pectoral fins were made at 143 hours 37 minutes and the tail was separated started at the same time. Hatching was observed at 167 hours 27 minutes after blastodisc. The total length of the hatched larvae was 4.95~5.10 mm (mean, 5.01 mm), the mouth and anus were opened. Larvae used yolk completely after 3 days after hatching. The total length larvae was 5.45~5.56 mm (mean, 5.52 mm) after 8 days after hatching, and appeared the stems for tail. The stems pectoral, anal fin were showed after 14 days and the stems dorsal, ventral fin were appeared after 19 days. For 35 days after hatching, the total length of larvae 13.95~15.30 mm (mean, 14.64 mm), and at this time, fins and body were transferred like the adult Oryzias latipes.

• International Journal of Industrial Entomology and Biomaterials
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• 제4권2호
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• pp.117-120
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• 2002

Scelionid eggParasitoids Play an important role in biological control of some economically important pentatomids. Stink bug (Canthecona furcellatta Wolff,) is an important predator of Tasar silkworm larvae (Antheraea mylitta D.) and causes 30-40 percent loss in tasar silk industry. Psix striaticeps (Scelionid: Hymenoptera) has been found to be an important egg parasitoid. The parasitization potential of f striaticeps is mere than 60 percent and the sex ratio is female oriented. Studies indicate that the maintenance of existing scelionid population by avoiding harmful practices and the augmentation of scelionids either directly releasing them in the field or by indirectly making the field environment more favorable for them is an important aspect to control the pentatomid population in sericulture. Female bias sex ratio is advantageous to increase the parasitoid population in the field. 24-hour-old egg of stink bug and one-day old parasitoid is suitable for producing maximum progeny. 1 : 30 of parasitoid: host ratio is needed to regulate the estimated population in silkworm rearing field.

• Journal of Ecology and Environment
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• 제36권1호
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• pp.11-17
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• 2013

The life cycle of butterflies is closely related to the growth of food plants and, through a prolonged coevolutionary process, has undergone an ecological adaptation. So, it is important that control the egg-laying number and place to secure enough food plant by female adult to guarantee the survival of the larvae. To study whether oviposition control of the Luehdorfia puziloi takes into greater consideration food plant leaf biomass or leaf abundance, correlation among the egg cluster size, the leaf size, and the number of leaves around egg clusters was investigated. According to the results, the egg clusters size exhibited positive correlation with the leaf size of food plants on which eggs had been laid but did not do so with the number of surrounding leaves. In addition, the number of egg clusters laid exhibited positive correlation with the number of surrounding food plant leaves but not with the leaf size on which eggs had been laid. Consequently, for the Luehdorfia puziloi, the females' recognition of the leaf size seems to be the most important factor in the egg cluster size, and the number of egg clusters had positive correlation with food plant density per unit area.

• Environmental Analysis Health and Toxicology
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• 제17권1호
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• pp.1-6
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• 2002

Effects on nonylphenol (NP) treatment on early development of fertilized eggs and survival of larvae in olive flounder, Paralichthys olivaceus were investigated. Fertilized eggs and hatched larvae were exposed to aqueous solutions of NP at nominal concentrations of 50, 100, 150 and 200 $\mu\textrm{g}$/L. In the control I and II (methanol-carrier control) groups, the hatchability of fertilized eggs were 90.7$\pm$7.02 and 90.0$\pm$5.29％ (P <0.05), respectively. However, treatments of NP concentrations at 50, 100, 150 and 200 ug/L were reduced to 78.7$\pm$4.16, 46.0$\pm$9.17, 48.0$\pm$3.46 and 33.3$\pm$11.02% (P<0.05), respectively. The time to hatching of fertilized eggs was delayed in high-dose NP treatment groups rather than control groups. Fertilized eggs of NP immersed group could not hatch normally, and also vertebra of the larvae observed as abnormal shape. Cumulative mortality of hatched larvae after 26hr NP treatment was 38.3, 78.3, 88.3 and 100% in NP 50, 100, 150 and 200 ug/L treatment groups, respectively. Whereas, control I and II were 11.7, 16.7% (P<0.05). Hatched larvae showed most death at the embryonic development stage with abnormalities. These results suggest that NP treatment in fertilized eggs and larvae was inhibited as normally development for fertilized egg and growing of larvae.

• 한국발생생물학회지:발생과생식
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• 제22권3호
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• pp.289-295
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• 2018

Large quantity of eggs fail to be fertilized and many of fertilized eggs are unable to hatch in the eel, Anguilla japonica. Larvae of eel absorb egg yolk up to 8 days after hatching but the majority of hatched larvae die before they reach the stage of first feeding in this species. Genes of key enzymes for yolk processing (cathepsin B, D, L and lipoprotein lipase - abbreviated as ctsb, ctsd, ctsl and lpl, respectively) could be associated with egg quality. In this study, we investigated differences in the expression of these genes between floating eggs and sinking eggs, and also the relationship between the gene expressions of the enzymes and fertilization rates in the fertilized eggs obtained from artificially matured female eels. Expressions of yolk processing enzyme genes did not show significant difference between floating and sinking egg groups. Expression of ctsb decreased when fertilization rate was high. Expression of ctsd, ctsl and lpl, however, did not show any significant differences. These results suggest that ctsb expression could be an indicator of egg quality, and that some proteins prone to be digested by ctsb could be very important in the process of fertilization and normal cleavage in this species. Further study should identify these critical proteins to improve our understanding on the quality of fish eggs.

• 한국가금학회지
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• 제32권3호
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• pp.203-209
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• 2005

본 연구는 산란계에서 파리 유충의 사료 영양학적 가치를 평가하고, 그 활용 가능성을 검토하고자 실시하였다. 43주령 갈색 산란계(ISA Brown) 총 90수를 51주령까지 8주 동안 각 시험사료 처리구(대조구, 파리 유충 2, 5, 10, $15\%$ 첨가 사료)에 임의배치하여 무제한 급여하면서 사료 섭취량, 산란율, 난황색, 난중, 파란 강도, 난각 두께, Haugh unit, 계란 내 지방산 조성 및 콜레스테롤 함량을 조사하였다. 파리 유충 첨가구가 대조구에 비해서 난중이 유의적으로 높았으며(p<0.05), 파란 강도 증가율은 $14\%$ 높게 나타나 유의적인 차이를 보였다.(p<0.05). 계란 지방산 조성은 파리 유충 첨가구가 대조구에 비해서 포화지방산의 함량은 $16\%$까지 감소되었으나, 불포화 지방산의 함량은 $7\%$까지 유의적으로 높게 나타났다(p<0.05). 이 실험 결과 파리유충이 산란계 사료에 첨가되면 계란의 품질은 개선되었지만 난황에서 포화지방산이 증가비율이 높게 나타났다.