• 한국발생생물학회지:발생과생식
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• 제22권3호
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• pp.205-212
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• 2018

This study is to observe the developmental process of the larval skeleton according to the growth of the trident goby, Tridentiger obscurus belonging to the larvae and juveniles and use it as the basic data of the taxonomic study. 8 days after hatching, the parasphenoid was ossified with an average total length of 3.62 mm, and basioccipital began to ossify. Caudal vertebrae and neural spine ossified in vertebra. 17 days after hatching, the average total length of the long hairs was 4.32 mm, pterotic and epiotic were ossified, and interhyal and subopercle were ossified. 52 days after hatching, the average total length of the juvenile was 18.2 mm, and lateral ethmoid, hypohyal ossified, vertebrae were parapophysis, and epural bone was osseous to the bone.

• 한국발생생물학회지:발생과생식
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• 제9권2호
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• pp.135-142
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• 2005

무척추동물에서 척추동물에 이르기까지 대부분의 난생동물들의 난황 단백질의 전구체를 vitellogenin(VTG)이라 한다. 난생 척추동물에서 VTG는 간에서 합성되어 혈액을 통해 난세포로 전이된다. 암컷 어류는 정상적인 생식주기에서 난황단백전구체 형성이 시작되면 혈중 농도는 급격히 증가하게 된다. 수컷도 VTG의 유전자를 가지고 있기 때문에 낮은 수준의 내인성 에스트로겐으로 아주 적은 양의 단백질이 있을 수 있다. 그렇지만 수컷에 외인성에스트로겐 유사물질에 노출되면 그 양은 증가하게 된다. 따라서 어류에서 VTG는 내분비계 장애물질 효과를 조사하는 유용한 생물학적 추적자로 사용할 수 있다. 이 연구에서는 에스트로겐 유사물질에 오염된 지역에 서식하는 망둑어류의 혈중 VTG의 수준을 정량할 수 있는 방법을 제공하고자 한다. 이러한 목적을 위해 꾹저구(Chaenogobius annularis)의 VTG를 분리하고, 이에 대한 단클론 항체와 다클론 항체를 제작하여 혈중 VTG 수준을 정량할 수 있는 sandwich 경합 ELISA system을 만들었다. 난황 단백질에 대한 단클론 항체와 다클론 항체를 사용한 ELISA system에 대한 타당성 검토를 하였다. 순차적으로 희석한 암 컷의 혈청에 대한 흡광도 곡선은 VTG 표준농도의 곡선과 평행하였으나 수컷의 혈청에 대한 흡광도 곡선은 평행하지 않았다. 이 VTG에 대한 sandwich ELISA system으로 꾹저구(C. annularis)의 혈중 VTG의 수준을 정량뿐만 아니라 문절망둑(Acanthogobius flaviman)과 풀망둑(A. hasta)의 혈중 VTG 수준을 정량할 수 있다.

• Parasites, Hosts and Diseases
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• 제47권3호
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• pp.307-310
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• 2009

Fishborne trematode (FBT) metacercariae were investigated in yellowfin goby, Acanthogobius flavimanus, collected from Shinan-gun and Muan-gun, Jeollanam-do (province), Korea. All collected fishes were examined using the artificial digestion method. In all of 15 gobies from Aphae-myeon in Shinan-gun, metacercariae of Stictodora spp. (334 metacercariae/fish), Heterophyes nocens (153/fish), and Heterophyopsis continua (20/fish) were detected. In 2 of 14 gobies from Jido-myeon in Shinan-gun, 8 Echinostoma hortense metacercariae in total were detected. In 15 gobies from Haeje-myeon in Muan-gun, the metacercariae of H. continua were found in 100%, Stictodora spp. in 86.7%, and H. nocens in 6.7% of fish examined. The average numbers of metacercariae per infected fish were 23.3 (H. continua), 416.0 (Stictodora spp.), and 2.0(H. nocens), respectively. The metacercariae of E. hortense found in gobies were elliptical, with 150 ${\times}$ 138 ${\mu}m$, in average size, and had 27 collar spines on the head crown. The above results suggest that yellowfin gobies from 2 localities may be the potential infection sources of FBT. Moreover, it is proved for the first time that the yellowfin goby, A. flavimanus, acts as a second intermediate host for E. hortense.

• 한국수산과학회지
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• 제51권1호
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• pp.54-63
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• 2018

We investigated the effect of $CO_2$ exposure on the reproductive process of chameleon goby Tridentiger trigonocephalus. Rearing aquaria were exposed for 90 days to $CO_2$ gas through diffuser connected with pH controller maintaining at pH 7.2 ($156.31{\pm}7.90ppm$) in low treatment, and at pH 6.5 ($274.17{\pm}6.51ppm$) in high treatment. $CO_2$ treatment had no significant effects on survival rates although the value was decreased compared to the controls. In female fish, $CO_2$ treatment had no significant effects on gonadosomatic index (GSI), hepatosomatic index (HSI) and condition factor (CF). However, high $CO_2$ treatment decreased HSI and CF in males significantly compared to the controls (P<0.05). The spawning occurrence was 6 times in the low level $CO_2$ treatment, and 4 times in the high level $CO_2$ treatment although only once in the controls. For the histological observations, there was no significant difference in $CO_2$ treatments. However, in male fish, $CO_2$ treatment delayed the formation of sperm from spermatid compared to controls. These results suggest $CO_2$ may disrupt reproductive process by delaying gametogenesis in chameleon goby and it was more sensitive in males.

• 한국발생생물학회지:발생과생식
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• 제17권4호
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• pp.353-361
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• 2013

The objective of this study was to characterize the reproductive cycle of the chameleon goby, T. trigonocephalus. Gonadal development was investigated using a histological method. Specimens were collected monthly, from April 2009 to March 2010. The gonadosomatic index (GSI) of females began to increase in April, reaching the maximum in May, and declined sharply in August. In males, the GSI began to increase in April and reaching the maximum in July. The annual reproductive cycle of T. trigonocephalus can be divided into four successive stages in females: the growing (November-March), maturing (April-May), ripe and spawning (June-July), and recovery (August-October) stages. Males passed through growing (November-March), maturing (April-June), ripe and spermiation (July-August), and recovery (September-October) stages. These results indicate the spawning season is from June to July. The relationship between fecundity (Fc) and body length (BL) was $Fc=86.1511BL^{2.6506}$. Fecundity was ranged from 3,448-9,654 eggs in a BL of 4.8-7.2 cm and it was increased as BL increased.

• 한국발생생물학회지:발생과생식
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• 제18권1호
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• pp.51-56
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• 2014

This study describes the developmental process of gonads in chameleon goby, Tridentiger trigonocephalus from the stage of hatching to 100 days after hatching (DAH). Based on histological observation, the primordial germ cells were observed in mesentery between mesonephric duct and gut at 15 DAH (total length, TL: $6.8{\pm}0.2mm$). At 20 DAH (TL: $7.9{\pm}0.1mm$), the primordial gonad began to protrude into peritoneal cavity and developed between mesonephric duct and gut. Initial ovarian differentiation was identified by the presence of ovarian cavity and oogonia in the gonads at 55 DAH (TL: $21.1{\pm}1.3mm$). Testicular differentiation started at 65 DAH (TL: $23.7{\pm}0.9mm$) with appearance of spermatogonial cells in the gonads. These findings indicate that sex differentiation in T. trigonocephalus occurs earlier in females than males, suggesting that this species can be classified as an undifferentiated gonochorist.

• Animal cells and systems
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• 제16권4호
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• pp.343-349
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• 2012

A variety of fish species undergo an ontogenetic change in prey selectivity, and several potentially interacting factors, including nutrient requirement, microhabitat change, and foraging ability, may account for the occurrence of the shift. Here we examine the foraging ecology and ontogenetic diet shift of a micro-carnivorous goby, Pterogobius elapoides (serpentine goby), dominant component of fish assemblage in shallow rocky areas off the coast in Korea and Japan. Although most other gobies are primarily benthic carnivores, P. elapoides is a semipelagic fish; however, little is known about how those species change their foraging tactics with growth. In our diet analyses, the most common diet was pelagic copepods and benthic amphipods, and diet shift was observed from pelagic to benthic with growth. The ontogenetic diet shift seems to be the result of the preference for energetically more profitable prey in larger-size classes as well as the results of different prey availability due to among-habitat variation in diet. However, differential food preference does not appear to affect individual scope for searching food. Several factors such as predation pressures and interspecific resource partitioning might contribute to the changes in diet observed among size classes, which were included in our ongoing tests.

• 한국발생생물학회지:발생과생식
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• 제27권3호
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• pp.127-135
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• 2023

Effects of changes in photoperiod on the reproductive events in fish are suggested to be mediated mainly via the action of melatonin (MEL). Changing levels of plasma MEL throughout the day and year are suggested to influence the hypothalamus-pituitary-gonadal axis in fish. Therefore, in this study, we aimed to investigate the effects of MEL on oocyte maturation and germinal vesicle breakdown (GVBD) in the marine fish, Chaenogobius annularis, in vitro. Oocytes at three different stages (pre-, mid-, and late-vitellogenesis) were incubated with (a) only MEL (5, 10, 50, 100, 500, and 1,000 pg/mL) and (b) 50 pg/mL of 17α,20β-dihydroxy-4-pregnen-3-one (17α20βP), maturation-inducing hormone (MIH) of this species, and MEL (4-h incubation before addition of MIH). Any single MEL treatment did not significantly induce GVBD. However, treatment with 50 pg/mL MEL or MIH significantly induced GVBD. These results suggest that preincubation with MEL accelerates the effect of MIH on longchin goby oocyte maturation.

• Fisheries and Aquatic Sciences
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• 제4권4호
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• pp.265-267
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• 2001

In this study, lipid classes and fatty acids composition in viscera and muscle of the philippines Pinkgray goby, Amblychaeturichtys hexanema were determined. The viscera contained high levels of total lipid $(TL,\;4.8\%)$, while the muscle contained less TL $(0.5\%)$. TL in the viscera consisted of triacylglycerol $(83.9\%)$, diacylglycerol $(7.9\%)$, polar lipid $(7.4\%)$, and cholesterol $(0.8\%)$. However, the muscle contained a small amount of TG $(3.0\%)$ and much more PL $(73.8\%)$. Principal fatty acids composition of PL and NL in the viscera and muscle were 16:0, 16:1n-7, 18:0, 18: 1n-9, 18:1n-7, l8:3n-3, 20:5n-3, 22:5n-3, and 22:6n-3.

• Fisheries and Aquatic Sciences
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• 제8권2호
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• pp.83-89
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• 2005

Morphology, histology, and histochemical characteristics of the digestive tract of the guirine goby (Rhinogobius giurinus: Gobiidae), collected from the coast of Jeju Island, Korea, were investigated. The digestive tract of R. giurinus, which is a brackish water species, has a short (relative length of gut=0.42), simple, and narrow gut. The gastric glands are well developed in the stomach, but pyloric caeca are absent. The mucosal folds are regularly branched, and the muscularis extern a is thickest in the esophagus, which also contained the most mucus-secreting goblet cells (P<0.05). In R. giurinus, digestive function occurs in the anterior portion of the digestive tract, where mucus protects the tract from the actions of digestive enzymes and functions to activate digestion.