• Korean Journal of Fisheries and Aquatic Sciences
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• v.33 no.6
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• pp.554-558
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• 2000

Reproductive biology of the female red tongue sole, Cynoglossus joyneri was investigated by means of histological methods. Gonadosomatic index (GSI) was the highest in June. Developmental pattern of oocytes was group-synchronous. Egg stalk and yolk nucleus were observed in the early growing oocytes. Reproductive cycle could be classified into the growing ($February{\~}May$), maturation ($May{\~}June$), ripe and spent ($June{\~}August$), and recovery and resting ($August{\~}February$). The absolute fecundity per individual ($TL 28.1{\~}30.8 cm$) was 2,197 and relative fecundity per g body weight was 18.0.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.37 no.3
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• pp.226-231
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• 2004

Maturation and spawning of Acentrogobius pflaumi were studied using samples collected from the Gwangyang Bay, Korea, from January to December, 1999. The gonadosomatic index (GSI) of the female was the highest in May. The spawning season lasted from May to June. There was a significant difference in the 1 : 0.59 sex ratio between males and females (p<0.01). The percentage of sexually mature females was over $50\%$ for the size group between 4.5 cm and 4.9 cm, and $100\%$ for the size group over 5.5 cm in body length. The size of eggs spawned was between 0.4 to 0.6 mm, and the spawning occured once a year. Fecundity varied between 3,600 and 9,700 eggs. The relationship between the fecundity and body length of the fish was expressed in the fecundity equation as; $F=0.294{\times}10^3\;BL^{1.899}.$ The first spawning length was 4 cm BL.

• Ocean and Polar Research
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• v.40 no.1
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• pp.15-22
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• 2018

In the present study, we investigated temporal variation in the reproductive effort and biochemical contents in adult Manila clam Ruditapes philippinarum at Shi-Heung-Ri beach on the east coast of Jeju Island. Gonad-somatic index (GSI), a ratio of the egg mass to the total biomass determined using ELISA increased dramatically from late May to June (7.1% to 19.5%). In mid-July, GSI dropped to 15.1%, indicating spawning on a small scale during this period. GSI also declined dramatically from late August (15.5%) to September (4.3%), suggesting that massive spawning occurred during this period. A positive correlation was observed between clam size and potential fecundity, while potential fecundity ranged between 1.19-8.40 million eggs/clam. Total proteins and lipids in the tissue increased from late spring to mid-summer, coinciding with an increase in GSI. Protein, lipid and carbohydrate contents in the tissue were lowest in January, indicating that clams were suffering from poor nutritional circumstances, which may be associated with poor food supply from the environment. Monthly increase and/or decrease in the body weight were closely related to gonad maturation and subsequent spawning, which was also linked to temporal changes in the contents of protein, lipid and carbohydrates in the tissue.

• Journal of Bio-Environment Control
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• v.13 no.1
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• pp.56-60
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• 2004

The aphidophagous lady beetle, Harmonia axyridis, is induced to undergo reproductive diapause by low temperature treatment. The diapause of the adult beetle can be maintained without supplying the diet up to 5 months at $4^{\circ}C$. The diapause can be induced any time including during the summer, allowing the beetle to be supplied to the field for the control of aphids through the year. Fecundity and longevity after the reproductive diapause is though to be satisfactory enough for the control of aphids in the field, Methoprene, an analog of reproductive hormone of JH, increases the early fecundity of the beetle.

• The Korean Journal of Zoology
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• v.30 no.2
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• pp.99-106
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• 1987

It is the purpose to investigate the physiological toxity and mutagenicity by heavy metal compounds such as potasium dichromate, sodium arsenite and selenium dioxide on the development of Drosophila melanogaster. These chemical compounds were highly toxic at every developmental stage of Drosophila. The relative values of fecundity, viability and developmental time obtained on food media containing 5 different levels of potasium dichromate (500, 600, 700, 800, and 900 ppm), also 5 different levels of sodium arsenite and selenium dioxide (10, 15, 20, 25 and 30 ppm). Resulting in the relative values of fecundity and viability generally decreased, on the contrary developmental time generally reduced as the concentration of chemicals in the food increased. A significant reduction in the fecundity was observed between 800 and 900 ppm (p<0. 01) on the potasium dichromate media, between 15 and 20 ppm (p<0. 05) on the sodium arsenite media, between 20 and 25 ppm (p<0. 02) on the selenium dioxide media. A significant reduction in the viability was observed between 700 and 800 ppm (p<0. 01) on the potasium dioxide media, between 25 and 30 ppm (p<0. 01) on the sodium arsenite media, between 20 and 25 ppm (p<0. 01) on the selenium dioxide media. The developmental time was significantly reduced between 800 and 900 ppm (p<0. 001) on the potasium dioxide media, between 15 and 20 ppm (p<0. 001) on the sodium arsenite media, and between 25 and 30 ppm (p<0. 01) on the selenium dioxide media.

• The Korean Journal of Zoology
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• v.30 no.2
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• pp.107-116
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• 1987

It is the purpose to investigate the physiological toxity and mutagenicity by heavy metal compounds such as potasium dichromate, sodium arsenite and selenium dioxide on the development of Drosophila melanogaster. These chemical compounds were highly toxic at every developmental stage of Drosophila. The relative values of fecundity, viability and developmental time obtained on food media containing 5 different levels of potasium dichromate (500, 600, 700, 800, and 900 ppm), also 5 different levels of sodium arsenite and selenium dioxide (10, 15, 20, 25 and 30 ppm). Resulting in the relative values of fecundity and viability generally decreased, on the contrary developmental time generally reduced as the concentration of chemicals in the food increased. A significant reduction in the fecundity was observed between 800 and 900 ppm (p<0. 01) on the potasium dichromate media, between 15 and 20 ppm (p<0. 05) on the sodium arsenite media, between 20 and 25 ppm (p<0. 02) on the selenium dioxide media. A significant reduction in the viability was observed between 700 and 800 ppm (p<0. 01) on the potasium dioxide media, between 25 and 30 ppm (p<0. 01) on the sodium arsenite media, between 20 and 25 ppm (p<0. 01) on the selenium dioxide media. The developmental time was significantly reduced between 800 and 900 ppm (p<0. 001) on the potasium dioxide media, between 15 and 20 ppm (p<0. 001) on the sodium arsenite media, and between 25 and 30 ppm (p<0. 01) on the selenium dioxide media.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.54 no.1
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• pp.46-52
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• 2021

The maturation and spawning of Pacific cod Gadus macrocephalus were inversigated using 2,415 samples collected monthly from January 2017 to December 2019, in the Yellow Sea of Korea. We analyzed monthly changes in gonadosomatic index (GSI), maturity stage, egg diameter (mm), the relations fecundity and total length (cm). The spawning period was February to March. Fecundity varied between 334,836 and 2,099,600 eggs. The relationship between the fecundity and TL of fish was expressed in F=186.86TL2.0954 (R2=0.7359). The percentage of sexually mature females estimated from a logistic function was over 50%, 75% and 97.5% for the size (TL) 39.3, 44.8 and 57.7 cm.

• Korean journal of applied entomology
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• v.47 no.4
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• pp.365-368
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• 2008

Adult longevity and fecundity of the foxglove aphid, Aulacorthum solani Kaltenbach, were studied at $12.5{\sim}25^{\circ}C$ with $60{\sim}70%$ RH under 16L:8D and the results were put together to build a life table. The longevity of foxglove gradually increased with decreasing temperature below $25^{\circ}C$. Also total fecundity increased with decreasing temperature and highest fecundity was 74.1 nymphs per female at $15^{\circ}C$. However, daily fecundity increased with increasing temperatures up to $20^{\circ}C$ showing 2.9 nymphs per day and thereafter decreased. Net reproduction rate ($R_0$) was highest of 58.7 at $15^{\circ}C$. The intrinsic rate of increase per day ($r_m$) and the finite rate of increase per day (${\lambda}$) were highest of 0.27 and 1.32, respectively and the doubling time (Dt) was shortest of 2.52. the mean generation time (T) was 10.99 at $22.5^{\circ}C$.

• Korean journal of applied entomology
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• v.48 no.3
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• pp.361-368
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• 2009

We have investigated some biological characteristics, such as survival rate and fecundity, of Orius laevigatus and Phytoseiulus persimilis, which have been stored at 6, 8, 10, $12{\pm}1^{\circ}C$, RH $70{\pm}10%$, in dark condition. Overall, an appropriate temperature for cold storage was $10^{\circ}C$ for O. laevigatus and $8^{\circ}C$ for P. persimilis. 70% of adult O. laevigatus could survive for 36 days at $10^{\circ}C$. The O. laevigatus stored at $10^{\circ}C$ for $10{\sim}50$ days laid $37.1{\sim}120.5$ eggs. Since fresh (no storage) O. laevigatus laid 224.5 eggs, comparative fecundity of stored adults was $16.5{\sim}53.7%$ of normal fecundity. P. persimilis stored at $8^{\circ}C$ for $7{\sim}2$ days with (food eggs of Tetranychus urticae) laid $11.9{\sim}18.9$ eggs. Since fresh P. persimilis laid 26.4 eggs, comparative fecundity of stored adults was $45.1{\sim}71.6%$ of normal fecundity.

• Korean Journal of Veterinary Research
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• v.31 no.1
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• pp.11-18
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• 1991

The purpose of this study was designed to investigate the methods for the functional elevations of sperm-host (utero-vaginal, U-V) glands in domestic hens. The laying hens were assigned to five groups of low-, medium-, high- fecundity, gonadotrophin-, and caffeinetreated hen groups, these group hens were sacrified at interval after last artificial inseminations (AI). Number of U-V gland observed in tissue preparation of each hen U-V region were investigated, and also the appearance rates of spermatozoa-contained U-V glands were calculated. 1. In low-fecundity hen groups, the appearance rates of spermatozoa-contained U-V glands were found to be 13.5, 15.6, 11.8, 13.6, 2.3, 0, and 0% respectively at the hens of 1, 3, 7, 10, 13, 16, and 19 days after AI. 2. In medium-fecunditiy hen groups, the appearance rates of spermatozoa-contained U-V glands were found to be 21.7, 22.7, 13.4, 10.4, 10.0, 7.7 and 0% respectively at the hens of 1, 3, 7, 10, 13, 16, and 19 days after AI. 3. In high-fecundity hen groups, the appearance rates of spermatozoa-contained U-V glands were found to be 30.8, 31.8, 28.9, 13.0, 10.3, 10.8, and 0.9 respectively at the hen of 1, 3, 7, 10, 13, 16, and 19 days after AI. 4. In gonadotrophin-treated hen groups, the appearance rates of spermatozoa-contained U-V glands were found to be 31.8, 33.7, 32.3, 17.3, 12.0, 5.0, and 1.0% respectively at hens of 1, 3, 7, 10, 13, 16, and 19 days after AI. 5. In caffeine-treated hen groups, the appearance rates of spermatozoa-contained U-V glands were found to be 33.2, 29.2, 22.4, 17.8, 12.7, 0, and 1.1% respectively at hens of 1, 3, 7, 10, 13, 16, and 19 days after AI. 6. The appearance rates of completely filled U-V glands and partially filled U-V glands of spermatozoa-contained U-V glands were found to be 3.8:1. So we suggested as follows: The appearance rates of spermatozoa-contained glands tend to be high from 1 day after AI to 7 days and tend to declined rapidly from 10 days. Also higher fecundity hen groups tend to be higher in the appearance rates and longer in spermatozoa-contained duration in U-V glands than in lower fecundity hen groups. Gonadotrophin hormone tend to increase the appearance rates of spermatozoa-contained U-V glands than those in control group, whereas caffeine tend to increase those rates at 1 day and to declined more rapidly from 3 day than in control group.