• Korean Journal of Ichthyology
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• v.33 no.1
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• pp.8-14
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• 2021

Spawning behavior of the endangered Korean fish, Microphysogobio koreensis, was investigated in the Seomjingang (river), Imsil-gun, South Korea, during the spawning season, April to May 2012. The mating system of M. koreensis, a broadcast spawner, was a primitive spawning mode, and involved one male and one female, unlike group spawning fishes. Spawning behavior of M. koreensis in the wild were observed in eight patterns as resting, male chase, body beating, parallel swim, female withdrawal, male competition, spawning and not guard while spawning behavior in the glass tank were verified in six patterns as resting, male chase, body beating, parallel swim, spawning and not guard. In particular, a behavioral attempt of the pre-spawning stage showed more frequently in the wild than in the glass tank. We assume that difference of spawning behavior might be implication on behavioral restrictions in small and narrow indoor glass tank.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.53 no.1
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• pp.98-102
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• 2020

We examined the comparative spawning ecology of daggertooth pike conger Mureanesox cinereus and common pike conger M. bagio in the South Sea of Korea from May 2018 to December 2019. In the South Sea of Korea, the mean total length (TL) of M. cinereus was significantly smaller than that of M. bagio. The sex ratios of both species were skewed toward females. The spawning period of M. cinereus was from June to October, while the spawning period of M. bagio was from August to October. The lengths at 50%, 75%, and 97.5% sexual maturity of M. cinereus females were estimated as 54.6 cm, 60.4 cm, and 74.1 cm TL, respectively. It was not possible to estimate lengths at sexual maturity for M. bagio in the South Sea of Korea due to the absence of immature stages.

• Journal of Environmental Science International
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• v.31 no.10
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• pp.861-868
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• 2022

The Namdae stream in Gangneung-si is one of the rivers where salmon stock is mainly maintained by natural spawning rather than artificial seedlings. There are structures including weir, and fish distribution and movement characteristics can be different by these structures. In this study, we investigated the distribution and behavioral characteristics of salmon by sighting survey within 12 km immediately upstream of the river mouth between October 2021 and February 2022. As a result, salmon distributed within 9 km from rivermouth. There were more salmon in the lower reaches of Doosan weir than in the upper reaches of that. The main spawning ground for salmon was between 7-9 km from rivermouth and around the lower part of Doosan weir. Salmon behaved for spawning in the gravel-bed area and undercut slope of the mainstream, such as mating, digging the riverbed, and competition among males. Salmon moved more slowly in the gravel-bed area than sand-bed area. Doosan weir hinders the spawning migration of salmon by frequent flow changes and terraced fishway. This study provides primary information to understand the ecological changes of salmon by environmental changes in the Namdae stream.

• Korean Journal of Ichthyology
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• v.36 no.3
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• pp.209-219
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• 2024

A survey was conducted in 2011 to investigate the reproductive ecology and spawning behavior of the natural monumental and endangered species, Cobitis choii. C. choii exhibits sexual dimorphism with the development of lamina circularis on the second pectoral fin ray in males at one year old, facilitating easy differentiation between males and females. A total of 1,288 females and 881 males were collected from January to December, resulting in a sex ratio of 1 : 0.68. The spawning season was estimated to be from late June to early July (spawning peak from late June, with water temperatures ranging from 22 to 25℃), coinciding with a sharp decrease in the condition index. Gonadal maturity was observed with maturity indices of 17.5±2.11% for females and 2.9±0.46% for males, with fecundity of 2,444±838 eggs and egg size of 0.75±0.05 mm. Spawning behavior was induced by hormone injection (Human Chorionic Gonadotropin, HCG) in laboratory conditions. Experimental results revealed that males and females paired in a 1 : 1 ratio before spawning. Males pressed the abdomen of females using their lamina circularis to induce spawning, followed by immediate fertilization. Spawning behavior was repeated 15 to 25 (average 20) times per pair of males and females, and 80 to 120 eggs were spawned per time, and the total amount of spawned eggs were 2,500±250 on average.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.55 no.4
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• pp.349-355
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• 2019

Reproductive ecology of rabbit fish, Siganus fuscescens were investigated from samples collected monthly in the coastal waters off Jeju Island of Korea from February to December 2014. In male and female of S. fuscescens, the values of GSI were reached high values between July to August in which the water temperature was high, and then decreased until December. The occurrence of individuals which have mature eggs in ovary were higher from July to August. Therefore, a main spawning season was estimated from July to August, with the highest peak in July. Throughout histological observation of the ovary in the spawning period, S. fuscescens belong to an group-synchronous and has a one spawning season a year. Fecundity of ovary ranged from 380,000 to 2,600,000 during the spawning period. Size at 50% sexual maturity, determined from logistic equation, were 25.1 cm TL which is over two years.

• Korean Journal of Ecology and Environment
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• v.38 no.2 s.112
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• pp.207-216
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• 2005

Spawning behaviors of Squalidus gracilis majimae (Cyprinidae) were observed in the laboratory whose environmental factors such as light (D/L = 16 : 8), temperature ($20\;{\sim}\;24\;＾{\circ}C$), and dissolved oxygen (>8 mg $L^{-1}$) were quite regularly controlled. The behavioral patterns were categorized into three stages ofpre-spawning, spawning, and Post-spawning behaviors. In Particular, the pre-spawning stage was specified by 11 specific behavioral patterns of aggressive mating behaviors. During the spawning stage, the male and female performed four distinct spawning behaviors including sexual temptation, stimulation, egg spawning, and the separation, and randomly laid about 200 ${\sim}$ 300 eggs on the bottom substrates through the night. After finishing spawning, two adults separated toward their refuges and showed 3 types of post-spawning behaviors such as the resting, occasional eggs protecting, and the egg eating. The fish was identified as a partial-parental care species after the spawning.

• Korean Journal of Ichthyology
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• v.10 no.2
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• pp.176-183
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• 1998

Spawning ecology and feeding habits of Maurolicus muelleri in the Korean waters were studied. M. muelleri spawned continuously throughout the year showing a peak in August. Major spawning ground of this species was the southeastern sea of Korea. The fecundity observed from the ovaries of M. muelleri showed a range of 5,072 to 32,117, and the average number of eggs per one spawning time was approximately 250. M. muelleri was a zooplanktivore which fed mainly on copepods. Its diets also included various crustaceans such as amphipods, euphausiids, shrimps and mysids.

• Journal of the Korean Institute of Landscape Architecture
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• v.35 no.6
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• pp.48-63
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• 2008

This research is to apply suitable natural ecosystem evaluation criteria in order to develop the ecosystem conservation, restoration and ways to build substitute habitats as a compensation plan for damaged soundly natural ecosystems in small-scale projects such as resource recovery facility, filtration, etc. The environmental ecology evaluation i.e. generally based on their actual vegetation, community structure, wildlife, water system survey were measured the primary plans for reflecting unique natural environment level of site. As a result, it is necessary to conserve the land in fallow type of wetland, good conservative condition of deciduous forest, wetlanded watercourse for amphibia and reptiles crossing. However, the plan of filtration plant was destroyed wetland(sound ecosystem), natural forest, asian toad spawning area. According to the result of it schemed to build alternative wetland and spawning area, plan to healthy ecosystem and surface soil transplantation as compensation plan. The alternative wetland and spawning area are not only created a various water levels like depth of water is $0{\sim}30cm,\;30{\sim}60cm$, more than 1.5m but also it leads to asian toad spawning and wildlife inhabitant. Moreover, the ecosystem and surface soil transplantation be applied to use the Quercus acutissima forest resources(114 upper trees, 71 canopy trees, 401 shrubs) and surface soil$(5,072m^3)$ in ecology creation sets.

• Korean Journal of Ichthyology
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• v.23 no.2
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• pp.158-162
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• 2011

Growth and spawning ecology of Cobitis lutheri (Teleoste: Cobitidae) were investigated in the Samcheon Stream, Mangyeong River, Jeollabuk-do, Korea from 2005 to 2006. Age group of C. lutheri estimated from the total length indicated that the 40 ~ 60 mm group is 1 year old, the 60 ~ 80 mm group is 2 years old, and the 80 ~ 110mm group is 3 ${\leq}$ years old. The sex ratio (Male/Female) was 0.78, and the female was 20 ~ 30 mm larger than the male. Lamina circularis at the base of pectoral fins in the males as a secondary sexual character was created 12 months after hatching. A change of lateral coloration of males was observed from April to September. The spawning season was early to middle July with water temperatures of $24{\sim}26^{\circ}C$. The average number of eggs was $1,127{\pm}453$ with the egg diameter of $1.09{\pm}0.02$ mm.

• The Korean Journal of Ecology
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• v.19 no.5
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• pp.477-486
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• 1996

The freshwater goby, Micropercops swinhonis ($G\"{u}nther$) was studied on the spawning behavior and egg develeopment at the two areas of Chollabukdo, Korea from March to May 1995. Egg mass attached to a layer under stones and the inner wall of waterplant, Cyperus. Spawning behavior was divided in to 1) premating stage: selecting spawning sites and formation of territory by male, 2) mating stage: enticement with zigzag-like dance and intermittant shaking of head by male and fertilization, 3) postmating stage: fanning, guarding and cleaning the nest by male. The eggs were transparent and spherical in shape, measuring $0.9\times1.4mm$ with yellowish yolk sac and many oil globules. Hatching began in about ten days after fertilization at water temperature $16~20^{\circ}C$. The newly hatched larvae were 3.8~4.0 mm in total length with 30 myomeres and their mouths and anuses were opened. Melanophores appeared at the air-bladder and the ventral side of caudal region.gion.