• Korean journal of applied entomology
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• v.55 no.4
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• pp.445-452
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• 2016

Exorista japonica is one of the major natural enemies of noctuid larvae, Mythimna separata and Spodoptera litura. The examined parasitoid was obtained from host species M. separata, collected at Gimje city and identified by DNA sequences (partial cytochrome oxidase I, 16S, 18S, and 28S). For purposed of this study, laboratory reared S. litura served as the host species for the development of the E. japonica. The developmental period of E. japonica immature stages were investigated at seven constant temperatures (16, 19, 22, 25, 28, 31, $34{\pm}1^{\circ}C$, RH 20~30%). Temperature-dependent developmental rates and development completion models were developed. E. japonica was successfully developed from egg to adult in $16{\sim}31^{\circ}C$ temperature regimes. Developmental duration was the shortest at $34^{\circ}C$ (8.3 days) and the longest at $16^{\circ}C$ (23.4 days) from egg to pupa development. Pupal development duration was the shortest at $28^{\circ}C$ (7.3 days). Total immature-stage development duration decreased with increasing temperature, and was the shortest at $31^{\circ}C$ (16.3 days) and the longest at $16^{\circ}C$ (45.4 days). The lower developmental threshold was $7.8^{\circ}C$ and thermal constant required to complete total immature-stage development was 370.4 degree days. Among four non-linear temperature-dependent developmental rate models, Briere 1 model had the highest adjusted R-squared (0.96). The distribution model of development completion for total immature stage development of E. japonica was well described by all model ($r^2_{adj}=0.90$) based on the standardized development duration. These results of study would be necessary not only to develop population dynamics model but also to understand fundamental biology of E. japonica.

• The Korean Journal of Malacology
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• v.31 no.2
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• pp.103-112
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• 2015

Bay scallop (Argopecten irradians) has been farmed only in the South Sea of Korea. East Sea Fisheries Research Institute (ESFRI) has developed bay scallop aquaculture technologies to extend its aquaculture area to the Southeast Sea of Korea. For the artificial spawning, the water temperature was maintained at $23^{\circ}C$. Over 100,000,000 eggs were spawned through artificial spawning inductions, such as air exposure and thermal shock by rising the water temperature. The fertilization rate was over 91% with nearly 94,000,000 fertilized eggs. The shape of fertilized eggs was spherical with an average diameter of $61.7{\pm}0.05{\mu}m(54.1-67.4{\mu}m)$. Five days after fertilization, the eggs developed into prodissoconch shell, and continuously grew into umbo stage and then umbones stage. After 8 days of fertilization, the size of larva became $179.7{\pm}8.4{\mu}m$ on average ($150.4-204.8{\mu}m$), and the larva formed a foot and an eye spot. The larvae grew to $235.4{\pm}9.7{\mu}m$ in 10 days and attached to adherence material, becoming juvenile bay scallop. The shells grew from 22.71 mm to 72.40 mm in 6 month (June-December). The total weight increased from 2.0 g to 32.7 g at the same period. The daily growth rates of young scallop were $0.35mm\;d^{-1}$ (Apr. to Jun.) and $0.41mm\;d^{-1}$ (Jun. to Aug.), which were comparable to those found in the South Sea. These findings suggest that the bay scallop aquaculture may be suitable in the Southeast Sea of Korea and may provide an additional crop to aquaculturists.

• Korean Journal of Ichthyology
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• v.11 no.1
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• pp.46-51
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• 1999

Age, hatching date and growth in length of juvenile Limanda yokohamae were determined by analysis of microstructure in otoliths. Monthly samples were collected by a beach seine in the shallow water off Gaduk-do from January to December, 1998. The juveniles were collected between February and April. Mean total length was $22.6{\pm}1.77\;mm$ ($\pm$SD) in February, $23.6{\pm}3.86\;mm$ in March, and $38.2{\pm}8.38\;mm$ in April. The core of otoliths ranged from 18 to $21\;{\mu}m$ in diameter and the growth increments were deposited concentrically from the hatching mark. The secondary growth layer began to appear at the 48 to 56-th increment. It indicates that L. yokohamae larvae may be completed the metamorphosis at this time of ca. 52 d after hatching, and moved into the shallow water for demersal stage. The hatching date calculated from the number of daily increments was between late November and early January, showing a peak in December. The total length (L, mm) was related to otolith radius (R, ${\mu}m$); L=0.055 R+5.81 ($r^2=0.88$). The growth in total length was represented by the Gompertz growth curve; $L_t=3.39e^{4.51(1-e^{-0.0067t})}$ ($r^2=0.81$). Daily growth rate was 0.35 mm/d at the age of 70 d and increased up to 0.55 mm/d at the age of 120 d.

• Korean Journal of Ichthyology
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• v.27 no.2
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• pp.86-94
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• 2015

Egg development and early life history of the endangered species, Microphysogobio rapidus was investigated to get a basic information for biological characteristics and recovery strategy. Eggs were obtained from females by injecting Ovaprim (0.5 mL/kg) and artificially fertilized by dry method in the laboratory. The mature eggs were slightly adhesive and separated with light bluish green and $0.63{\pm}0.02mm$ (n=20) in diameter. Number of eggs in the ovaries were $3,827{\pm}1,225$ (2,850 ~ 5,916). The hatching occurred at 72 hours after fertilization under water temperature of $21{\pm}1^{\circ}C$. The newly-hatched larvae were $2.79{\pm}0.04mm$ (n=10) in total length. At 5 days after hatching, they were average $4.10{\pm}0.07mm$ (n=10) in TL and their yolk sacs were completely absorbed. 30 days after hatching, they became to juvenile stage and reached $9.74{\pm}0.24mm$ (n=10) in TL. At 100 days after hatching, the band patterns and external form were similar to those of adults, average $27.00{\pm}1.94mm$ (n=10) in TL.

• Korean Journal of Ichthyology
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• v.27 no.2
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• pp.95-103
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• 2015

Egg development and early life history of the Korean spine loach, Cobitis tetralineata, were investigated in the present study. Adult fish were sampled using spoon nets at the Seomjin River in Jeongsan-ri, Bokheong-myeon, Sunchang-gun, Jeollanbuk-do, Korea, July 2013. Eggs were obtained after injecting Ovarprim into females. Eggs were then artificially fertilized using the Dry method in the laboratory. Mature eggs were slightly adhesive and transparent with grey coloring, and measured $1.04{\pm}0.03mm$ ($mean{\pm}SD$) in diameter. Hatching of the embryo occurred approximately 56 hours after fertilization at $25^{\circ}C$ of water temperature, and the average size of newly hatched larvae was about $4.6{\pm}0.11mm$ in total length. At fifth day after hatching, the larval full length reached $6.8{\pm}0.28mm$ on average and their yolk sac had been completely absorbed. At 17th day after hatching, larva entered the juvenile stage and reached $9.8{\pm}0.50mm$ in total length. At 100th day after hatching, the formation of Gambetta's zone of four line was complete and juveniles were similar in general appearance to adults, and they averaged $34.7{\pm}5.77mm$ in total length.

• Korean Journal of Animal Reproduction
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• v.16 no.1
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• pp.63-76
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• 1992

This study was carried out to investigate the appearance time of the second polar body for producing Gynogenesis or Triploid which could be obtained by arresting the second polar body by cold shock, and then blastoderm was used to measure fertility that revealed the nature of oogenesis, the effects of water temperature on fertility, hatchability, abnormality, viability and growth rate, and the water temperature and the breeding methods to prevent early death of larvae in Korean loach(Misgurnus anguillicaudatus) ; the results obtained in this study were summarized as follows. The second polar body was observed ont he surface of plasma disc close to micropyle within 10~40 min after fertilization at 29$^{\circ}C$. Artificial inseminatin had to be done immediately after the egg spawning because the spermatozoa of loach their mobility within 2 minutes when they were exposed to water. The amount of time needed to reach at blastoderm stage was 12 hours if fertilized eggs were incubated at 16$^{\circ}C$, 8 hours at 19$^{\circ}C$, 6 hours at 21$^{\circ}C$, 5 hours at 23$^{\circ}C$, 4 hours at 26$^{\circ}C$ and 3 hours 30 min at 29$^{\circ}C$ showing the shorter time for development of eggs at higher temperature. Fertilization rates in water temperatures of 19$^{\circ}C$, 21$^{\circ}C$, 23$^{\circ}C$, and 26$^{\circ}C$ were higher than those of water temperatures, 16$^{\circ}C$ and 29$^{\circ}C$. Water temperatures at 19$^{\circ}C$, 21$^{\circ}C$, and 23$^{\circ}C$ showed higher hatching rates that those of 16$^{\circ}C$, 26$^{\circ}C$, and 29$^{\circ}C$, while abnormal rates in 16$^{\circ}C$, 19$^{\circ}C$, 21$^{\circ}C$ and 23$^{\circ}C$ were lower than that of 26$^{\circ}C$ and 29$^{\circ}C$. Water temperatures at 16$^{\circ}C$, 19$^{\circ}C$, 21$^{\circ}C$, 23$^{\circ}C$ and 26$^{\circ}C$ respectively, were more different than 29$^{\circ}C$ in survival rates. The embryos were hatched at 72 hours after fertilization in 16$^{\circ}C$ water temperature, 48 hours in 19$^{\circ}C$, 40 hours in 21$^{\circ}C$, 32 hours in 23$^{\circ}C$, 25 hours in 26$^{\circ}C$, and 16 hours in 29$^{\circ}C$. Within three days after hatched out, the larvage grew 3mm in total length, the yolk granules were entirely consumed and the head and the trunk became thicker. Within 45 days after hatched out, the larva grew 25mm at 29$^{\circ}C$, 21mm at 26$^{\circ}C$, 16mm at 23$^{\circ}C$, 15mm at 21$^{\circ}C$, 12mm at 16$^{\circ}C$ in a 30 litreglass aquarium.

• Journal of Pharmacopuncture
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• v.19 no.4
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• pp.319-328
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• 2016

Objectives: Advancements in nanotechnology have led to nanoparticle (NP) use in various fields of medicine. Although the potential of NPs is promising, the lack of documented evidence on the toxicological effects of NPs is concerning. A few studies have documented that homeopathy uses NPs. Unfortunately, very few sound scientific studies have explored the toxic effects of homeopathic drugs. Citing this lack of high-quality scientific evidence, regulatory agencies have been reluctant to endorse homeopathic treatment as an alternative or adjunct treatment. This study aimed to enhance our insight into the impact of commercially-available homeopathic drugs, to study the presence of NPs in those drugs and any deleterious effects they might have, and to determine the distribution pattern of NPs in zebrafish embryos (Danio rerio). Methods: Homeopathic dilutions were studied using high-resolution transmission electron microscopy with selected area electron diffraction (SAED). For the toxicity assessment on Zebrafish, embryos were exposed to a test solution from 4 - 6 hours post-fertilization, and embryos/larvae were assessed up to 5 days post-fertilization (dpf ) for viability and morphology. Toxicity was recorded in terms of mortality, hatching delay, phenotypic defects and metal accumulation. Around 5 dpf was found to be the optimum developmental stage for evaluation. Results: The present study aimed to conclusively prove the presence of NPs in all high dilutions of homeopathic drugs. Embryonic zebrafish were exposed to three homeopathic drugs with two potencies (30CH, 200CH) during early embryogenesis. The resulting morphological and cellular responses were observed. Exposure to these potencies produced no visibly significant malformations, pericardial edema, and mortality and no necrotic and apoptotic cellular death. Conclusion: Our findings clearly demonstrate that no toxic effects were observed for these three homeopathic drugs at the potencies and exposure times used in this study. The embryonic zebrafish model is recommended as a well-established method for rapidly assessing the toxicity of homeopathic drugs.

• Journal of Sericultural and Entomological Science
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• v.34 no.1
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• pp.1-7
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• 1992

For a long-term preservation of silkworm stocks by frozen gonad storage, fundamental topics such as freezing rate and transplanting stage of the gonad, proper cryoprotectant, and super-cooling temperature and freezing point of the freezing medium were examined and following results were obtained. Proper method to anesthetize the ovary-recipient silkworm was to dip the animal to cold water for 10 minutes, and the ovary taken from the 4th instar larvae was more suitable for freezing-preservation than that from the 5th. Concerning the cryoprotectant, glycerol and DMSO were effective to prevent cryoinjury of the ovary, but sorbitol was not. The supercooling temperature and freezing point of the medium to freeze the ovary and testes were checked, and consulting with the results desirable cooling rate was confirmed. On the desirable conditions of transplanting methods, freezing rate and cryoprotectant concentration ect., the next generation was obtained when the females implanted frozen-thawed ovaries mated with normal males, but none of the normal females mated with the males implanted frozen-thawed testes laid fertilized eggs. Now it is needed to improve the connecting ration of the ducts associated with the transplanted testis to those of the hosts.

• Current Research on Agriculture and Life Sciences
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• v.15
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• pp.69-81
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• 1997

For the prevention of worldwide prevalent disease of nuclear polyhedrosis virus (NPV), environmental conditions and their incidence of grasserie was investigated through 57 cases of silkworm rearing from the year of 1979 to 1993 in the countries of Korea, Japan, and Philippines. Relationship between the occurrence of NPV and environmental factors were also analysed from the aspect of causal pathogenesis. Unfavorable foactors related to the prevalence of NPV disease was reconfirmed by the assay of experimental rearing. Silkworms reared on mulberry leaves or artificial diet appeared similar result on the occurrence of grasserie. Disinfection by formalin and simple sweeping or washing was not significantly different on the occurrence of NPV disease. Following insufficient ventilation on the younger larvae. from the 1st to 3rd instar, the disease by NPV at the later stage was remarkably emphasized those insidence. An experimental rearing from 1993 to 1996 demonstrated the prevention of NPV disease by simple cleaning of sweeping under the condition of air forced ventilation, the customal practice of disinfection with formalin or any other chemical agents could be omissible.

• Journal of Sericultural and Entomological Science
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• v.51 no.2
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• pp.107-113
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• 2013

The black soldier fly larvae are able to decompose various organic wastes such as livestock manures and food wastes. We tested whether the quality of the insect derived compost, i.e. larval feces, was comparable to that of a commercial fertilizer. Chemical analysis of Hermetia. illucens compost was suitable as a fertilizer. When the kidney bean (Phaseolus vulgaris L.) was raised on the culture soil treated with the H. illucens compost, the growth of leaf area, total dry weight and leaf dry weight increased significantly. The H. illucens compost is thought to act as an increasing factor of RGR (relative growth rate) from the beginning of growth and also had a great effect on the relative growth rate throughout the late stage of growth. There is high statistical significance between NAR (net assimilation rate) and RGR (relative growth rate), but no significance between RGR and LAR (leaf assimilation rate) of the treatments. In addition, the treatment of H. illucens compost promoted the thickness of leaves from the beginning of growth and the tendency of thickening leaves from the beginning of growth and the effect continued throughout the late period of growth. When mixed with 50% of H. illucens compost rather than 25%, it showed the greater effect on the plant growth.