• The Korean Journal of Ecology
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• v.22 no.5
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• pp.271-276
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• 1999

Luminescent patterns of the firefly Hotaria papariensis were classified into routine flashing and courtship flashing, and they were analyzed into duration and period. Flash period of male was changed from 1.26 sec (routine flashing) to 1.12 sec (courtship flashing) and the female's was changed from 2.99 sec to 1.06 sec in this species. Duration time of male increased approximately 1.4-fold from 0.12 sec (routine flashing) to 0.17 sec (courtship flashing) and period of male decreased 0.88-fold from 1.26 sec (routine flashing) to 1.12 sec (courtship flashing). Duration of female increased about 1.5-fold from 0.15. sec (routine flashing) to 0.19 sec (courtship flashing) and period of female decreased almost 0.35 from 2.99 sec (routine flashing) to 1.06 sec (courtship flashing). Hertz frequencies of them were 0.8 (routine flashing of male), 0.9 (courtship flashing of male), 0.3 (routine flashing of female) and 0.9 (courtship flashing of female), respectively. The spectral emission of H. papariensis was detected at 400 nm to 700 nm, and the highest peak wave length of this species was approximately 600 nm, but some 500 to 600 nm wave lengths were present.

• Korean Journal of Poultry Science
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• v.19 no.4
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• pp.205-215
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• 1992

This study investigated the characteristics of Korean Native Fowl (KW) to standarize the feeding regime and compared with those of broiler. The characteristics of KNF studied were meat productivities and carcass traits. The data were collected for 14 weeks from March to June, 1992, by recording from 200 birds(50 birds per each sex and 2 breed) were as follows ： 1. Average body weight at 14 weeks of age of Korean Native Fowl(KW) and broiler were 868.7g and 3,526.6g, respectively and were 26.6 times and 72.9 times of day old chicks weight averages, respectively. 2. The carcass yields during 9∼14 wks were 74.1∼78.5％ for KNF male, 73.g∼77.5％ for KW female, 72.2∼76.9％ for broiler male and 71.7∼76.4％ for female. It was shown that carcass yields of KNF was 2％ higher than that of broiler. 3. In edible portion, the yields of wings weight to carcass weight were 11.5∼12.4％ for KNF male, 11.5∼13.1％ for KNF female, 10.7∼11.9％ for broiler male and 10.7∼12.2％ for broiler female, it was shown that wings weight of KW was higher than that of broiler and wings weight of KNF during 9∼14 wks. 4. The portions of back and breast weight were higher than those of KNF during 9∼14 wks. The back portions in carcass weight were 15.4∼17.0％ for KW male 15.4∼16.8％ for KNF female, 17.2∼19.0％ for broiler male, and 17.2∼19.0％ for broiler female. The breast portions in carcass weight were 19.6∼22.0％ for KNF male, 20.2∼22.7％ for KNF female 23.S∼24.5％ for broiler male, and 25.1∼27.7％ for broiler female. 5. The portion of thigh and drumsticks weight in carcass weight of KNF was similar to that of broiler. They were 26.8∼28.0％ for KNF male, 25.5∼27.1％ for KNF female, 27.7％ for broiler male, and 26.9％ for broiler female, respectively. 6. For the weight of inedible portion during 9∼14 wks, feather weight of KNF was 5.3∼6.8％ of live weight and 3.8 ∼4.4％ in those of broiler. This result indicated that KNF has more rooms for improvement than broiler. 7. Abdominal fat weight was 2.42∼3.88g for KNF male and 1.84∼3.08g for KNF female, which was 0.5％ of carcass weight. But broiler has more abdominal fat than KNF as 39.4∼56.3 g for male, 33.3∼67.8 g for female which was 2.5 ∼3.0％ of carcass weight.

• Journal of Life Science
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• v.9 no.2
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• pp.182-193
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• 1999

In order to establish basic data of SAMP6 as an animal model for osteoporosis, present study has been designed to concentrate on the various biological aspects of SAMP6 such as growth index, hematology, blood biochemistry, biochemical characteristics, and bone and cortical thickness. Investigation period was for 15 months (3 months to 18 months of age) and biological characteristics have been examined throughout the study period. The results were summarized as follows : Decreased body weight of male SAMP6 was noticed from 7 months of age compared to from 18 months of age in female. Although there were no significant differences in organ weights, generally those of male mice were greater than those of females, especially in liver, kidney and lung. According to the analysis of blood biochemistry and hematology, the number of leukocytes in male mice was greater than that of female mice. There was a decrease in bone thickness in both male and female mice starting around from 7 months of age. Peak cortical thickness index was noticed at 5 months of age in both sexes. In femur, the highest $Ca^{2+}$ content for both sexes was noticed at 5 months of age, whereas the highest P$^{3+}$ content was noted at the age of 5 and 7 months in male and female mice, respectively. The contents of both elements were gradually decreased with age after peaks for both sexes. In summary, SAMP6 mice in KRICT colony show osteoporotic characteristics starting from 5 to 7 months of age, suggesting that at least 5 months of old animals should be used for studying the mechanism of osteoporosis or screening anti-osteoporosis drugs. This study also suggests that the cortical index thickness, $Ca^{2+}$ and P$^{3+}$ contents, and alkaline phosphatase activities can be used as indexes for drug screening.

• The Korean Journal of Pesticide Science
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• v.4 no.4
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• pp.40-47
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• 2000

The comparative toxicity of ten acaricides, seven insecticides and five fungicides to the two-spotted spider mite, Tetranychus urticae and its predators, Amblyseius womersleyi and A. eharai was evaluated by a leaf spray bioassay. Five of the acaricides tested, bifenazate, etoxazole, acequinocyl, flufenoxuron and chlorfenapyr were much less toxic to adult females of A. womersleyi and A. eharai than to T. urticae adult females. A. womersleyi adult females treated with five acaricides produced $52{\sim}93%$ as many eggs as untreated adult females. And A. eharai adult females treated with five acaricides laid $54{\sim}73%$ as many eggs as untreated adult females. The remaining acaricides showed high toxicity to adult females of A. womersleyi and A. eharai. All the insecticides tested were less toxic to T. urticae adult females than to adult females of A. womersleyi and A. eharai. However, tebufenozide and diflubenzuron did not significantly affect the survival and reproduction of adult females of A. womersleyi and A. eharai. All the fungicides tested showed low mortality (${\leq}24%$) to adult females of predatory mites. However, benomyl had significant effect on the reproduction of adult females of A. womersleyi and A. eharai. Four acaricides (bifenazate, acequinocyl, flufelloxuron and chlorfenapyr) were much less toxic to eggs of A. womersleyi and A. eharai than to T. urticae eggs. However, etoxazole caused relatively low hatchability ($58{\sim}62%$) of eggs of A. womersleyi and A. eharai. All the insecticides and fungicides tested did not significantly affect the hatch of eggs of predatory mites. It may be suggested from these results that four acaricides, two insecticides and four fungicides described could be Incorporated into the integrated mite management system with A. womersleyi and A. eharai in pear orchard.

• Korean Journal of Environment and Ecology
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• v.31 no.2
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• pp.127-134
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• 2017

This study was conducted to identify the reproductive behavior of the barn swallow. The study was carried out in Gwangju, Korea during the 2013 breeding season. In the morning, the nest-building frequency was 14.2~31.0 trips/h (10.2~19.8 trips/h by male and 4.0~11.4 trips/h by female). The nest-building activity took 7.6~15.9 min/h (4.8~8.1 min/h by male and 2.8~8.0 min/h by female). The nest-building time by female ($40.0{\pm}27.9sec/trip$) was about 1.5 times longer than the nest-building time by male ($26.1{\pm}15.5sec/trip$). Only the female incubated the eggs. The Incubation time was $50.6{\pm}17.5min/h$ (84%) at 6h, 24.5 min/h (40.8%) at 7h and 15.6 min/h (26.0%) thereafter. During daytime, the female incubation time showed a highly significant difference (p<0.001), and the incubation time at 6h was higher than that at other times. There was a significantly negative correlation between female incubation time and the mean air temperature(p<0.05). The frequency of feeding was $385.2{\pm}66.9trips/nest$ in the daytime ($219.2{\pm}37.1trips/nest$ by male and $166.0{\pm}30.8trips/nest$ by female). The frequency of feeding per hour was $32.1{\pm}12.3trips/h$ ($18.3{\pm}7.8trips/h$ by male and $14.3{\pm}4.5trips/h$ by female). The frequency of feeding per hour showed a significant difference in the range of 10h(p<0.05) and 15h(p<0.01) by sex. The time of feeding by female ($40.9{\pm}83.3sec/trip$) was longer than the time of feeding by male ($12.3{\pm}31.0sec/trip$). The juvenile defecation frequency was $45.6{\pm}8.4times/nest$ per day and showed a positive correlation with feeding frequency (p<0.05). The results of this study will be helpful in understanding the reproductive behaviors of the swallow adapted to the environment in Korea.

• Korean Journal of Ichthyology
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• v.24 no.3
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• pp.220-226
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• 2012

The aim of this study is to observe the reproductive behavior of the marine medaka, Oryzias dancena, and determine the factors of reproductive behavior to provide useful information for improving their artificial reproduction techniques. The reproductive behavior of the marine medaka was observed in laboratory aquaria. Once the experiment began, all of the males chased the females. The males attempted to stimulate the urogenital openings of the females. While chasing a female, a large male would bite a relatively small male's anus. Larger males expelled smaller males with biting, and the defeated males were barred from the female. After the other males were expelled, the remaining male approached and drew alongside the female. The male's dorsal and anal fins covered the female's body. Spawning began after complete covering took place. Spawning of males and females occurred simultaneously. The loadings for 2 factors were calculated. The calculation was restricted to 2 factors because these 2 factors explained about 81% of the total common variance (P<0.05) and the following factors possessed no practical significance. Two movements (biting, expelling) had high positive values for factor one. This factor related a male's defensive behavior to courtship behavior and spawning, and explained 23.1% of the total common variance (P<0.05). The second factor had high positive values for chasing, rejection, covering, and parallel swimming. This factor related a male's courtship behavior and female's defensive behavior to spawning, and explained 59.7% of the total common variance (P<0.05). This research provided basic biological data for the conservation of this species and useful information for improving their artificial reproduction techniques.

• Journal of Aquaculture
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• v.8 no.4
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• pp.295-306
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• 1995

The present study was performed to produce supermales and superfemales in Oreochromis niloticus by combination of induced sex reversal and diploid gynogenesis. More than $95\%$ of female was obtained by oral administration of $17\beta-estradiol$ (480 mg/kg diet) to the eutheroembryonic larvae of this species. The result of progeny tests with XY pseudofemales showed that incidences of male progeny were ranged from $71.4\%\;to\;73.7\%$. p.opo.lion of male from XY pseudofemale was not significantly different (P>0.05) from that of $\chi^2$ (1:3), but it was significantly different (P<0.01) from that of $\chi^2$(1:1) Gynogenetic diploids were produced by applying cold shocks 3 min after insemination to the eggs of XY pseudofemale sperms were genetically inactivated by ultraviolet rays of 4,050 $erg/mm^2$. Fertilization rates of gynogenetic diploids were not different from that of their controls, however, hatching rates and early survival rates were silghtly lower than those of controls. In the cytogenetic studies, there was no difference in the size of cell and nucleus between the gynogenetic diploids and the controls. At 80 days after hatching, frequencies of gynogenetic male were higher than those of gynogenetic female (P<0.01) in their population.

• Korean journal of applied entomology
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• v.33 no.2
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• pp.66-73
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• 1994

Adult emergence period, the calling behavior pattern and the mating ability of female depending on ages, 9day old male's response to sex pheromone released from each 1- to 5-day old female, and the structure and location of sex pheromone gland were obse~edin Ostrinia furnacalis. Adults usually emerged from 1 hour before to 1-2 hours after the beg~nning of scatophase under the 16L/8D photoperiod. And most active calling behavior was obserued for two hours from the 5th to 7th hours of scotophase among 2- and 3-day old females, and 3-day old male' response to 3-day old females was higher than to any other age of females during the 5th-8th hours of scotophase. Mating frequency was higher at the 4th-7th hours after the beginning of scotophase. Among 1. to Cday old females extruding sex pheromone gland, more than 65% of them successfully mated with 2- to 4-day old males. And, 2- or 3-day old females exhuding sex pheromone gland showed an abdiw. over 60%, to mate with each 1--5-day old males. Hypertrophied cell layers, presumed to be a sex pheromone gland of female adults, were located at two intersegmental membranes between the 8th & 9th, and the 9th & 10th abdominal segments.

• Korean Journal of Poultry Science
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• v.49 no.2
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• pp.89-98
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• 2022

This study compared the production and physiological characteristics of male and female Korean native commercial chickens. We investigated the growth performance, vitality, and stress response of 479 male and 608 female chickens from 1 d to 12 weeks of age. The body weight, feed consumption and feed conversion ratio were measured as growth performance. The survival rate, amount of telomeric DNA, DNA damage rate, heterophil-lymphocyte ratio (H/L ratio), and heat shock protein (HSP)-70, HSP-90α, and HSP-90β gene expression levels were analyzed as indicators of vitality and stress response. Body weight was significantly higher in male chickens than in female chickens after 2 weeks of age (P<0.01). Feed intake was higher in male chickens than in female chickens, whereas the feed conversion ratio showed the opposite trend. The survival rate was significantly higher in female chickens than in male chickens (82.8% vs. 73.8%, P<0.05). Stress response analysis revealed no differences between male and female chickens in terms of telomeric DNA content, DNA damage rate, H/L ratio, and HSP gene expression levels. Taken together, it was concluded that there was a significant difference in the growth performance and survival rate between male and female Korean native commercial chickens, whereas there was no difference in the degree of stress response between them. Therefore, in terms of the productivity of Korean native commercial chickens, it is judged that separate-sex rearing is much more advantageous than mixed rearing, regardless of the physiological characteristics of males and females.

• Korean Journal of Environment and Ecology
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• v.37 no.1
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• pp.76-85
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• 2023

This study aimed to understand social interactions by observing the courtship and attack behavior between individuals of 15 (6 females and 9 males) Reeves' turtle (Mauremys reevesii) in captivity in the Wolchulsan National Park. CCTV was installed in the study area from May 18, 2020 to October 19, 2020 and recorded 3 days a week (24 hours/day) for a total of 64 days and analyzed at intervals of 10 minutes per hour. Male turtle courtship was observed 884 times in total, with the heaviest females receiving the highest courtship frequency (357 times) and the smallest females receiving the least courtship (3 times). Of a total of observed 259 aggressive behaviors, 30 were for female to female, 81 for male to male, and 148 for female to male. Dominance hierarchy identified based on the result ranked females higher overall than males, and the larger the body, the higher the ranking. This study was the first in Korea to confirm individuals with high probability of reproduction through the frequency of courtship in the Reeves' turtle and investigate dominance hierarchy according to attack behavior. Our results can be used as reference behavioral data for managing and protecting the endangered Reeves' turtles and will help us understand their social structure.