• Fisheries and Aquatic Sciences
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• v.14 no.2
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• pp.111-117
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• 2011

The population dynamics of Pandalus gracilis was investigated in the southeastern coastal area of Korea between May 1998 and April 2000. Of the 4,127 specimens, 57% were identified as females, 39% as males, and 4% as transitional hermaphrodites. The number of females was greater than that of males and transexuals. A significant correlation was observed between the number of transitional hermaphrodites and ambient seawater temperature. Growth parameters were estimated using the modified von Bertalanffy growth function model incorporating seasonal variation in growth using the program ELEFAN. Females grew faster and reached a larger size-at-age than males (K=0.65/y and $L_{\infty}$=17.86 mm carapace length [CL] for females; K=0.51/y and $L_{\infty}$=14.70 mm CL for males). Mean size and age (95% confidence limits) at sex transition, calculated from growth parameters, were 7.07 mm carapace length and 1.05 years, respectively. The reproductive strategies of pandalid shrimps are discussed in terms of the type of sex transition.

• Korean Journal of Plant Taxonomy
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• v.41 no.3
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• pp.202-208
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• 2011

The present study was focused on the careful investigation of Glechoma longituba flowers collected from four populations in Korea to clarify their precise sexual systems. All floral characters of this taxon were examined by using a stereo microscopy. The nutlet size and production were compared between two distinct morphs (i.e., hermaphrodites and females), and pollen viability test of hermaphrodite and intermediate phenotype (i.e., individuals with a mixture of females and perfect flowers) was also observed by light microscopy (LM). All of the investigated floral characters of G. longituba are significantly different from one sexual morph to another. Hermaphroditic plants were larger than the female ones in corolla width and length, calyx length, filament length, anther length, and style length (all P < 0.0001, respectively). However, the nutlet width of the female plants was larger than those of the hermaphrodites (P = 0.013). Nutlet production of females was higher than hermaphrodites in Na-Ju population [H (Hermaphrodite): ca. 17.76%, F (Female): ca. 37.45%], but in Mun-San population was no significant difference between these sexual morphs (H: ca. 57.52%, F: ca. 53.16%). We have found significant differences between the fertile pollen grain of hermaphrodite and sterile pollen grain of intermediate phenotype based on pollen size and viability. The results of the present study suggest that compensation (flower size dimorphism, seed set, and pollen viability) is one of the main mechanisms in order to maintain female plants in gynodioecious G. longituba.

• Mycobiology
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• v.38 no.4
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• pp.282-285
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• 2010

Cordyceps cardinalis successfully produced its fruiting bodies from multi-ascospore isolates. However, subcultures of multiascospore isolates could not produce fruiting bodies after few generations. Fruiting body production also differed from sector to sector of the same isolate. Single ascospore isolates were then co-inoculated in combinations of two to observe the fruiting characteristics. Combinations of certain isolates produced perithecial stromata formation, whereas other combinations did not produce any fruiting bodies. These results show that C. cardinalis is a heterothallic fungus, requiring two isolates of opposite mating types for fruiting body production. It was also shown that single ascospore isolates are hermaphrodites.

• Korean Journal of Ichthyology
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• v.4 no.2
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• pp.72-76
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• 1992

The sex ratio and gonadal histology were investigated in the Cobitis lutheri Rendahl collected from the Tamjin River of Chollanam-do Province. Korea. The ratio of males declined in proportion to increase in size, while that of females increased in proportion to increase in size. Hermaphrodites were found in the intermediate size fishes. They had degenerating testicular tissue and developing ovarian tissue simultaneously. These phenomena were discussed in relation to skewed sex ratios.

• Development and Reproduction
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• v.25 no.1
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• pp.55-57
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• 2021

Samples were collected from the subtidal region of Jumunjin on the eastern coast of Korea in July 2020. A total of 338 mussels of shell height (SH) 20.8-149.8 mm were used for sex ratio analysis. The sex ratio (F:M) in the same population of mussel Mytilus coruscus was approximately 1:0.7. The sex ratio according to the class of SH was different. The sex reversal pattern of M. coruscus appears to go from male → female → male → female, and as such is determined to be sequential hermaphrodites.

• Fisheries and Aquatic Sciences
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• v.1 no.1
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• pp.82-93
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• 1998

Monthly changes of the gonad follicle index (GFI), reproductive cycle, egg-diameter composition, first sexual maturity of the Pacific oyster, Crassostrea gigas, were studied based on the samples which have been collected from the intertidal zone of Poryong west coast of Korea, from January to December, 1996. C. gigas, is dioecious, while a few individuals are alternatively hermaphroditic. Monthly variation of gonad follicle index (GFI) used for determination of spawning period, coincided with the reproductive cycle. GFI increased from April when seawater temperatures gradually increased and reached the maximum in May. And then, GFI sharply decreased from June to September due to spawning. Reproductive cycle of this species can be divided into five successive stages: in females, early active stage (March to April), late active stage (April to May), ripe stage (May to August), partially spawned stage (June to September) and spent/inactive stage (September to February); in males, early active stage (February to March), late active stage (April to May), ripe stage (May to September), partially spawned stage (June to September) and spent/ inactive stage (September to February). The diameter of fully mature eggs are approximately 50um. Spawning occurred from June to September, and two spawning peaks were observed in June and August when the seawater temperature was above $20^{\circ}C$. Percentages of the first sexual maturity of males of 20.1-25.0 mm in shell height were over $50\%$, while those of females of 25.1-30.0 mm in shell height were over $50\%$. All the males of > 30.1 mm and all the females of ^gt; 35.1 mm completed their first sexual maturity. The results suggest that C. gigas has a protandry phenomenon. Sex ratios of 919 oysters observed were 453 females $(49.29\%)$, 429 males $(46.68\%)$, 16 hermaphrodites $(1.74\%)$, and 21 indeterminate individuals $(2.29\%)$. In age class I, sex ratio of males were $64.00\%$, thus, a higher percentage than that of females. It was noted that $64.00\%$ of the young males (age class I) were more functional than females in age class I, but 2-3 year-old oysters showed higher percentage of females. Percentages of hemaphrodites in 2-3 year classes were relatively higher than those in other year classes. Histological pattern of hermaphrodites can be divided into two types: Type I (hermaphrodite having a number of newly formed developing oocytes on the oogenic tissues within a degenerating spermatogenic follicle after discharge of numerous spermatozoa) and Type II (hermaphrodite having two separate follicles in the same gonad).

• Korean Journal of Fisheries and Aquatic Sciences
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• v.36 no.6
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• pp.625-631
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• 2003

The aim of the present study was to investigate the ecological relationship between female body size (=shell length) and fecundity in a Korean population of protandric hermaphrodite, Crepidula onyx Sowerby, using 6 reproductive variables (the number of capsules per brood, capsule size, the number of embryos per capsule, total number of embryos per brood, egg size, and larval size). The investigation was based on 32 females, 107 egg capsules, 263 eggs, and 250 veliger larvae sampled in January 2000, from Yangpo, the southeastern coast of Korea. All foregoing reproductive variables, except larval size, were significantly correlated with the female body size (p<0.001$\~0.01$). There was a significant increase both in the number of capsules per brood and the number of embryos per capsule with female body size (p<0.001). Consequently, the fecundity of the female C. onyx increased with female body size to over 14.65 mm (the minimum size of egg brooding in the present study). This investigation, therefore, provides additional evidence that female fecundity of protandric hermaphrodites is positively correlated with female body size.

• Journal of Korean Medical classics
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• v.26 no.3
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• pp.19-32
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• 2013

Objective : Chu Cheng(褚澄) was known as the author of Zayaofang(雜藥方) and Chushiyishu(褚氏遺書). His mentions in the medicine have been sufficiently told in his posterity. However, there have been no studies on Chu Cheng and his work like Chushiyishu in Korea. Here, I seek to investigate Chu Cheng and his ideas in the medicine. Method : I investigate Chushiyishu, known as written by Chu Cheng and his scattered portions. Result & Conclusion : His nom de plume(字) is Yandao(彦道). It was supposed that he was born before the year of 420, the era of Dong Jin(東晉) and died in 483. He wrote Zayaofang and Chushiyishu. However, the former was lost. The latter consists of 10 pieces of medical theories. The contents carved on the stone plate was discovered for the first time before 934 at a place presumed as his grave. Then, it was stored as the inner and outer coffins in the tomb of Xiao Guang(蕭廣) in 935 and written on the paper by Buddhist monk Shi Yikan(釋義堪) in 1127. Then, Liu Jixian(劉繼先) carved on the wood for publication and finally, the work was released in 1201. But, it deeply looks that the book was written by other follower. Chu Cheng was a doctor excellent in the inspection and pulse method and his medical ideas prioritized Huo(火) in Mingmen(命門) and Spleen(脾). He expressed his opinions on the four phases of life, sexes and birth defects through Yangjing(陽精) and Yinxue(陰血). In addition, he explained the human pathology through Qixue(氣血). Unsmooth flow of Qi causes diseases by congestion. The entity circulating Yinxue is Yang and protested using urine to treat the hemoptysis(咳血) instead of medicine with cold features. It was frequently mentioned by his predecessors with the fact that Chu Cheng used different medications on housewives from widows and Buddhist nun monks. In addition, Chu Cheng proposed various opinions on cure, diagnosis, treatment, drug usage, pulse positions and hermaphrodites(半陰陽).

• Journal of Veterinary Clinics
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• v.29 no.5
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• pp.422-426
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• 2012

A 3-year-old Cocker spaniel was presented for evaluation because of a mass protruding from the vulva. This mass confirmed the presence of an internal bone in clitoris on the radiography. We recommended to the owner of the surgical removal of the gonads and uterus as well as the excision of the enlarged clitoris and os clitoris. The dog had gonads in the region of where the ovaries were located and presented what appeared to be a bicornate uterus and ductus deferens. Histological analysis revealed a morphologically normal uterus and two testes with their epididymis and ductus deferens. Karyotyping revealed a normal female chromosome constitution (78, XX), and polymerase chain reaction (PCR) identified the absence of Sry. Based on these findings, the patient was diagnosed with Sry-negative XX sex reversal.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.54 no.2
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• pp.180-187
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• 2021

This study was conducted to investigate the reproductive characteristics of the Neon damselfish Pomacentrus coelestis in Chuuk lagoon (7°27' N, 151°53' E), Micronesia, Equatorial Pacific Ocean. The specimens used in this study were collected from August 2009 to September 2010 from around the coral reef area at a depth of 3-10 m in the northwest coast of Weno Island. Overall, 228 individuals were collected over 14 months from this area, of which 115 were females and 108 were males. Among 108 males, 30 were found to be hermaphrodites and the sex of 5 individuals could not be determined. The overall sex ratio was approximately 1.06:1 (female:male), and the ratio of sexually active individuals was 0.79:1. The gonadosomatic index (GSI) fluctuated and showed the highest value of 8.43±1.21 in December 2009 and the lowest value of 3.36±0.71 in September 2009 in sexually active females. Males showed the highest GSI value of 2.64±0.93 in June 2010 and the lowest value of 0.35±0.06 in July 2010. Based on the fluctuation of GSI, the trends in the appearance of monthly sexually active individuals, and biopsy of the gonads, P. coelestis was found to be a hermaphrodite species of protogynous type and is considered to be reproductively active throughout the year.