• Parasites, Hosts and Diseases
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• v.50 no.1
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• pp.83-87
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• 2012

To determine the effects of kimchi extracts at different temperatures on larval development, $Ascaris$ $suum$ eggs were mixed with soluble part of 7 different brands of commercially available kimchi and preserved at either $5^{\circ}C$ or $25^{\circ}C$ for up to 60 days. $A.$ $suum$ eggs incubated at $25^{\circ}C$ showed marked differences in larval development between kimchi extract and control group. While all eggs in the control group completed embryonation by day 21, only 30% of the eggs in the kimchi extract group became embryonated by day 36 and about 25% never became larvated even at day 60. At $5^{\circ}C$, however, none of the eggs showed larval development regardless of the incubation period or type of mixture group. To determine the survival rate of $A.$ $suum$ eggs that showed no embryonation after being preserved at $5^{\circ}C$, eggs preserved in kimchi extracts for 14, 28, and 60 at $5^{\circ}C$ were re-incubated at $25^{\circ}C$ for 3 weeks in distilled water. While all eggs in the control group became larvated, eggs in the kimchi extract group showed differences in their embryonation rates by the incubation period; 87.4 % and 41.7% of the eggs became embryonated after being refrigerated for 14 days and 28 days, respectively. When refrigerated for 60 days, however, no eggs mixed in kimchi extract showed larval development. Our results indicate that embryogenesis of $A.$ $suum$ eggs in kimchi extract was affected by duration of refrigeration, and that all eggs stopped larval development completely in kimchi kept at $5^{\circ}C$ for up to 60 days.

• Parasites, Hosts and Diseases
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• v.54 no.1
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• pp.103-107
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• 2016

The objective of this study was to evaluate the effects of several different commercial disinfectants on the embryogenic development of Ascaris suum eggs. A 1-ml aliquot of each disinfectant was mixed with approximately 40,000 decorticated or intact A. suum eggs in sterile tubes. After each treatment time (at 0.5, 1, 5, 10, 30, and 60 min), disinfectants were washed away, and egg suspensions were incubated at $25^{\circ}C$ in distilled water for development of larvae inside. At 3 weeks of incubation after exposure, ethanol, methanol, and chlorohexidin treatments did not affect the larval development of A. suum eggs, regardless of their concentration and treatment time. Among disinfectants tested in this study, 3% cresol, 0.2% sodium hypochlorite and 0.02% sodium hypochlorite delayed but not inactivated the embryonation of decorticated eggs at 3 weeks of incubation, because at 6 weeks of incubation, undeveloped eggs completed embryonation regardless of exposure time, except for 10% povidone iodine. When the albumin layer of A. suum eggs remained intact, however, even the 10% povidone iodine solution took at least 5 min to reasonably inactivate most eggs, but never completely kill them with even 60 min of exposure. This study demonstrated that the treatment of A. suum eggs with many commercially available disinfectants does not affect the embryonation. Although some disinfectants may delay or stop the embryonation of A. suum eggs, they can hardly kill them completely.

• Parasites, Hosts and Diseases
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• v.52 no.1
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• pp.111-115
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• 2014

To evaluate the effects of pesticides to parasite eggs, Ascaris suum eggs were incubated with 5 different pesticides (1:1,500-1:2,000 dilutions of 2% emamectin benzoate, 5% spinetoram, 5% indoxacarb, 1% deltamethrin, and 5% flufenoxuron; all v/v) at $20^{\circ}C$ for 6 weeks, and microscopically evaluated the egg survival and development on a weekly basis. The survival rate of A. suum eggs incubated in normal saline (control eggs) was $90{\pm}3%$ at 6 weeks. However, the survival rates of eggs treated with pesticides were 75-85% at this time, thus significantly lower than the control value. Larval development in control eggs commenced at 3 weeks, and $73{\pm}3%$ of eggs had internal larvae at 6 weeks. Larvae were evident in pesticide-treated eggs at 3-4 weeks, and the proportions of eggs carrying larvae at 6 weeks ($36{\pm}3%-54{\pm}3%$) were significantly lower than that of the control group. Thus, pesticides tested at levels similar to those used in agricultural practices exhibited low-level ovicidal activity and delayed embryogenesis of A. suum eggs, although some differences were evident among the tested pesticides.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.51 no.3
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• pp.370-374
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• 2015

Pacific herring Clupea pallasii eggs were attached to the gill net in Korean coastal waters off Busan. To conservation and management the eggs attached to the gill net, we followed the natural hatching in coastal waters from five days after fertilization to the hatching finished, where the temperature was $9^{\circ}C$. The diameter of fertilized eggs was 1.24-1.55 mm (n= 50), and had a segmented pale yellow yolk, no oil globule. Natural hatching had started by 10 days after fertilization. Mass hatching occurred around 11-12 days after fertilization, most of eggs separated from the gill net. Therefore, when the Pacific herring eggs attached in gill net, should be natural hatching-induced in coastal waters during 12-14 days.

• Journal of Life Science
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• v.6 no.3
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• pp.171-177
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• 1996

It was carried out to find the carbohydrate metabolism for the glycogen utilization and the effects of low temperature(1$\circ$C, 5$\circ$C)on embryonic development of the silkworm, Bombyx mori L. The content of sorbitol and glycerol in the chillihg eggs stored at 5$\circ$C or 1$\circ$C on 24 hours after oviposition showed the highest level on the 50th day. After that, the corresponding value in the eggs stored at 5$\circ$C were decreased, and the value in the eggs stored at 1$\circ$C maintained the similar level. The trehalose level was rapidly increased on 50$\sim$60th day or thereabouts, and then, it was accumulated. When the eggs stored at low temperature were tranaferred and developed the embryo at 25$\circ$C, sorbitol and glycerol were respectively changed to glycogen. Futhemore, the content of trehalose and glucose showed specific of patterns with each embryonic stage at low temperature. With the aforementioned results, the intemediary metabolism of carbohydrate was discussed with regard to embryonic development of non-diapause eggs of silkworms.

• Environmental Analysis Health and Toxicology
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• v.17 no.1
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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.

• International Journal of Industrial Entomology and Biomaterials
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• v.9 no.1
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• pp.107-109
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• 2004

The present investigation reports a phenomenon hitherto unknown in tropical sericulture, wherein dia-pause nature of bivoltine eggs is overcome through a cross with a non-diapausing race of silkworm, Bombyx mori, L. Eggs of bivoltine silkworm Bombyx mori, L. generally do not hatch under tropical conditions. To prevent diapause, they are subjected to acid treatment or low temperature hibernation scheduled. A race developed at KSSRDI is found to prevent the diapause nature of bivoltine eggs when crossed as male parent, without any acid treatment or hibernation schedule. This phenomenon is reported for the first time, being unique, opens up interesting area of research in silkworm genetics of commercial implications in the industry.

• Korean Journal of Veterinary Service
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• v.24 no.4
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• pp.369-374
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• 2001

This study was conducted to investigate the hatchability and infertility of the ostrich eggs. Seven batches of ostrich eggs were imported from Australia into Korea in winter season under quarantine restrictions. Single stage incubation was carried out and the eggs were weighed before incubation. The weight of imported ostrich eggs was varied from 1,074 to over 1,650g and the average egg weights for batches were similar. The hatchability of all eggs batch was reached between 11 and 31%. The infertility of seven batches was varied from 36 to 63%. The first batch of eggs showed relatively low infertility(39％) and high hatchability (31％). On the contrary, the last batch of eggs had low Infertility(36%), and it had the lowest hatchability(11%). The result of this study suggests that hatchability of ostrich eggs imported in late laying season is significantly low because the number of infertile eggs is increased.

• Korean Journal of Animal Reproduction
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• v.13 no.3
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• pp.188-194
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• 1989

These experiments were carried out to investigate fertilizable and developmental ability after zona drilling the unfertilized eggs and the eggs not fertilized by the 1st insemination. The results of in vitro fertilization of the mouse eggs treated by using micromanipulation and acid tyrode's solution with capacitated epididymal spermatozoa were as follows. In the case of ovulated unfertilized eggs, according to sperm count(106, 105, 104 and 103/ml) the rates of in vitro fertlilization treated by zona drilling were 86.0%, 82.0%, 70.0% and 54.0%, respectively, and those of control were 58.0%, 52.0%, 12.0% and 8.0%, respectively. The rates of in vitro fertilization of zona drilled eggs were significantly high compared with those of control, and there were no significant difference between two groups. According to the sperm count the zona drilled eggs developed to the blastocysts were 51.4%, 40.5%, 23.3% and 17.4% and those of control were 35.7%, 26.3%, 0% and 0%, respectively. Also, in the eggs not fertilized by 1st insemination, the fertilization rates of oocytes reinseminated after zona drilling was significantly higher(83.5%) than that of control(34.7%), and the rates of polyspermy were similar. The rates of development to the blastocysts was 18.6% in the zona drilling treated eggs, and that of control was 27.3%, there was no significant difference between two groups. These results indicated that oocytes not fertilized by 1st insemination as well as ovulated unfertilized eggs could be fertilized, improve fertilizing rates by zona drilling treatment, and development potential were normal.

• Korean journal of applied entomology
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• v.47 no.4
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• pp.429-433
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• 2008

On the leaf disc of fruit vegetables (cucumber, sweet pepper, tomato, egg plant, oriental melon), it has been evaluated that the capability of four predatory mites (Amblyseius swirskii Athias-Henriot, Neoseiulus barkeri (Hughes), N. cucumeris (Oudemans), N. californicus (McGregor)) to prey on the eggs of Bemisia tabaci (Gennadius) and to lay own eggs. The most aggressive mite was A. swirskii which had consumed about $9{\sim}12$ eggs in a day. The quantity of eggs consumed by N. barkeri, N. cucumeris and N. californicus was about $6{\sim}9,\;4{\sim}6$ and $1{\sim}4$, respectively. The most productive mite was also A. swirskii which had laid about $1.2{\sim}1.9$ eggs in a day. The others could not lay more than 0.5 eggs in a day.