• Development and Reproduction
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• v.16 no.2
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• pp.87-93
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• 2012

Reproductive biology (maturation and spawning) of the female tongue sole Cynoglssus semilaevis were examined in 154 specimens caught from the west coast of Korea (between February and November 2010). Monthly changes of gonadosomatic index (GSI) and condition factor (CF) were peaked in September. Hepatosomatic index (HSI) showed a negative correlation with those of the GSI. Ovaries were classified into six stages based on the development of advanced oocyte and histological characteristics: virgin/immature, early developing, developing, late developing, ripe/spawning and spent/regressing stage. The relationship between fecundity (F) and total length (TL) of the fish was expressed as $F=251.43TL^{0.1264}$, and body weight (BW) was expressed as F=1130.4BW-880848. Biological minimum size of female was 46.87 cm (TL).

• Korean Journal of Fisheries and Aquatic Sciences
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• v.18 no.5
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• pp.477-483
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• 1985

This paper describes seasonal changes of total length, hepatosomatic index (HSI), fatness, egg-diameter composition, and fecundity of the longchin goby Chasmichthys dolichognathus(HILGENDORF). The specimens used were captured in the tide pool of Tongbaekseom, Pusan, Korea from February 1983 to January 1984. The age of longchin goby, tested by size frequency, was believed to be usually one year which grows to 8.0 cm in total length. The annual variations of HSI reached the maximum in the early spring when the gonad was actively growing and decreased during the spawning season from April to July. The coefficients of fatness were represented low values for the spawning periods. Frequency distribution of the egg diameter of mature ovary has three modes: one is the evident mode of the ripe eggs group, and the other two are modes of maturing and immature eggs groups. And an individual is considered as spawns one in the spawning season. Relationships between the fish size in total length (TL cm) and the number of ovarian eggs(F), the fish weight (BW g) and the number of ovarian eggs are indicated by the exponential equation respectively : F=42.585 $TL^{1.608}$, F= 524.589 $BW^{0.475}$.

• Korean Journal of Environment and Ecology
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• v.26 no.3
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• pp.367-373
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• 2012

Population ecology (Ecological characteristics) of Squalidus japonicus coreanus from the Namhan River(Yangpyeong-gun Yangpyeong-eup Changde-ri), Gyeonggi-do, Korea were investigated from January to December 2011. Short barbel gudgeon inhabits habitats run of the lower river. The stream bed was mostly covered sand. Their current velocities were 0.14~1.38m/sec and depths were 80~120cm. The sex ratio of female to male was 1 : 0.82. It is presumed that the spawning season is from June to July and water temperatures were $18.5{\sim}24.3^{\circ}C$. Sexually matured individuals appeared over the two year of age. Frequency analysis of total length indicated that the group with 34~50mm in total length was one year old, the 51~74mm was two years old, and the group over 75mm was three years old. The average number of eggs in the ovaries was estimated as 1,871 per matured female. Stomach content of S. japonicus coreanus were Cyanophyta, Chlorophyta, Bacillariophyta, Rotatoria, Crustaceae, Copepoda, Ephemeroptera, Diptera, and Nematoda. omnivorous, mainly feeds on benthic invertebrates such as chironomidae larvae.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.18 no.3
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• pp.261-265
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• 1985

Limanda yokohamae was studied on its growth, age at maturity, fecundity and survivorship, based on the specimens off the southeastern coast of Korea from December 1983 to November 1984. The total lengths at the formation of annulus on the otolith were back-calculated. The age at the first reproduction is 2yrs in both sexes. Fecundity was estimated to be $121{\times}10^3{\sim}429{\times}10^3$. Annual survival rate is 0.435 in female and 0.335 in male.

• Korean Journal of Ichthyology
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• v.7 no.2
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• pp.128-134
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• 1995

In order to study the taxonomic status of Cottus species from Korea, 19 morphological characters, egg number and size and hatched juvenile form in C. poecilopus and C. hangionsis were compared. The two species of C. poecilopus and C. hangionsis overlap each other in morphometric characters mostly, but snout length, caudal peduncle length and pectoral fin ray number were distinguished between them. Moreover the C. poecilopus and C. hangionsis specimens were differ from each other in the number of egg and size. The newly hatched juvenile form of C. hangiongensis produced many small eggs from which pelagic larvae were formed. In contrast, C. poecilopus produced well - developed juveniles. Two species have distinctly different life - cycles ; amphidromous for C. hangionsis and fluvial land - locked for C. poecilopus.

• Korean Journal of Ichthyology
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• v.23 no.4
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• pp.300-304
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• 2011

The reproductive characteristics of Chaenogobius gulosus was examined using 333 specimens collected monthly between October 2008 and September 2009 in the coastal waters of Tongyoung, Korea. Specimens ranged from 2.0 to 12.6 cm in standard length (SL). The gonadosomatic index (GSI) of females was highest in February and decreased until April, with the spawning season lasting from December to April. The monthly ratio of female to male did not significantly differ (${\chi}^2$-test, p>0.05). The size at 50% maturity for females was 7.9 cm SL. Fecundity ranged from 1,112 to 6,059 eggs, with a mean of 3,011 eggs.

• Korean Journal of Ichthyology
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• v.27 no.3
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• pp.217-227
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• 2015

Reproductive biology and population dynamics of Luciogobius guttatus were investigated. Higher gonadosomatic index (GSI) was observed from March~May. The fecundity ranged form 241 eggs at 3.1~4.0 cm (SL) to 716 eggs at 5.1~5.7 cm (SL). The relationship between length (SL) and fecundity (F) was $F=11.242SL^{2.464}$ ($R^2=0.65$) and fecundity increased with length. We estimated the SL at 50% group maturity as 2.6 cm. The spawning period was March~May. The von Bertalanffy growth function (VBGF) estimates were: $L_{\infty}=63.00mm$ TL; $K=0.85yr^{-1}$. The structure of recruitment pattern obtained by the FiSAT II program indicated one normally distributed group. The growth performance index (${\phi}$) was calculated with 3.53. Natural mortality rate (M) was $1.00yr^{-1}$.

• Korean Journal of Ichthyology
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• v.21 no.2
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• pp.93-99
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• 2009

The maturation and spawning of Black seabream Acanthopagrus schlegeli were investigated using samples randomly collected in the Southern Sea of Korea from March 2007 to February 2008. The FL at 50% sex-changers maturity was estimated to be 26.7 cm. We estimated monthly changes in maturity stages and gonadosomatic index (GSI). The spawning period ranged from March to July, and the peak spawning occurred in May and June. The fecundity (F) was 839,600 eggs at 32.2 cm fork length (FL) to 2,894,913 eggs at 42.0 cm FL, and the relationship between FL and F was expressed as $F=1.264FL^{3.869}$ ($R^2=0.736$). The FL at 50% group maturity was estimated to be 25.8 cm for females and 19.0 cm for males. The sex ratio was 19.9% for female, 20.9% for early sex-changers, 28.7% late sex-changers, 30.5% for male.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.31 no.1
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• pp.17-25
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• 1998

A fisheries biological study on the hairtail (Trichiurus lepturus LINNAEUS), which was collected from Cheju City, Hanrim, Sungsanpo and Seogwipo in Cheju Island, was carried out from June through December In 1992. GSI of the hairtail maintained relatively high from June to September, and then it began to decrease in October and remained low until December. The maturation and spawning period was between June and October, and the major spawning occurred in August. The hairtail turned out to be a multiple spawning species which spawn two or three times In a single spawning season. During the spawning season the number of females was greater than that of males, whereas the sex ratio was almost 1 : 1 during the rest of the season. Fecundity estimated from various sizes of the hairtail ranged from 12,821 to 125,876. The bigger the snout anal length and body weight of the hairtail was, the more eggs it possessed.

• Proceedings of the Korean Society of Fisheries Technology Conference
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• 2000.05a
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• pp.472-473
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• 2000

수산동물의 생식기구에 관한 연구는 우선 자연상태에서 각 종의 정확한 생식주기와 이를 지배하는 요인이 밝혀져야 하는데, 이는 자원증식을 위한 기본적인 연구과제이기도 하다. 참서대는 가자미 목, 참서대과에 속하는 경골어류이며, 한국 남서해안의 수심 70 m 이내의 연안이나 내만에 주로 서식하는 경제성이 높은 저서 정착성 어류이다. Genus Cynoglossus의 생식과 관련된 연구는 매우 적어서 용서대, Cynoglossus abbreviatus의 난소성숙의 유도 및 초기생활사 (Fujita et al., 1986)와 참서대, C. joyneri의 성장과 성숙에 관한 보고 (Choi et al., 1995)가 있을 뿐이다. 따라서 본 연구의 목적은 참서대 암컷 GSI의 월 변화, 포란수, 생식주기 및 생식주기에 따른 난소구조의 변화 등 생식생태를 조사하여 이들 어류의 자원증식을 위한 기초자료를 제공하기 위함이다. (중략)