• 한국수산과학회지
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• 제53권1호
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• pp.19-26
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• 2020

The maturity and spawning of pacific sand eels Ammodytes japonicus, was investigated using samples collected by gill net in coastal waters near Donghae, Gangwon-do, from January 2017 to December 2018. Monthly changes were analyzed in maturity stage, gonadosomatic index (GSI), egg diameter, fecundity (F), and total length (TL) at 50% group maturity. The average TLs of female and male A. japonicus were 18.5 and 18.1 cm, respectively. The spawning period was from November to March, with the peak from December to February based on monthly changes in GSI and maturity stages. The egg diameter during the spawning-capable stage was 300-1000 (main mode 500-600) ㎛. Fecundity ranged from 6,411 eggs at 16.7 cm fork length to 45,771 eggs at 24.7 cm fork length. The relationship between TL and F was F=0.00005TL^4.2715 (R²=0.7216), such that F increased with TL. TL at 50% group maturity was estimated to be 15.1 cm for both sexes.

• 한국패류학회지
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• 제22권1호
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• pp.39-49
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• 2006

Ultrastructure of germ cell differentiation during supermatogenesis and the reproductive cycle in male Patinopecten yessoensis was studied by histological and cytological observations. The gonadosomatic index (GSI) in males rapidly increased and reached a maximum in April when seawater temperature gradually increased. Then the GSI gradually decreased from May through July when spawning occurred. Accordingly, monthly changes in the GSI in males coincided with testicular maturation and spawning periods. The sperm morphology of P. yessoensis belongs to the primitive type and showed general characteristics of external fertilization species. The head of the spermatozoon is approximately $3.50{\mu}m$ in length: the sperm nucleus and acrosome are approximately $2.90{\mu}m\;and\;0.60{\mu}m$ in length, respectively. The nuclear type of the spermatozoon is vase in shape, and the acrosome is cone type. The axoneme of the tail flagellum consists of nine pairs of microtubules at the periphery and a pair of central microtubules in the center The satellite body (which is formed by the centriole) and four mitochondria appear in the middle piece of the spermatozoon. The spawning period was from April through July and the main spawning occurred from May to June when seawater temperatures gradually increased. The reproductive cycle of this species can be classified into five successive stages; early active stage (September to November), late active stage (October to March), ripe stage (February to August), spawning stage (April to July), and spent/inactive stage (July to November).

• 한국수산과학회지
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• 제42권3호
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• pp.297-301
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• 2009

The water temperature from 1980 to 2000 and the anchovy catch from 1990 to 2000 in the southeastern portion of the South Sea of Korea were used to illustrate the influence of water temperature on the catch of the anchovy, Engraulis japonica. 1993 and 1998 were selected as poor and good fishing years therefore, the horizontal and vertical distribution of water temperature and catch per unit effort in these years was compared. When the anchovy catch was lower, the water temperature at 10 m was also about $0-2^{\circ}C$ lower than during a normal year, which resulted in the formation of a weak thermocline. Conversely, when the anchovy catch was higher, the water temperature at 10m was $0-2^{\circ}C$ greater than during a normal year, which resulted in the formation of a strong thermocline at around 20 m.

• 한국수산과학회지
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• 제38권4호
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• pp.245-250
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• 2005

The maturity and spawning of Pacific cod, Gadus macrocephalus, was studied using samples caught by gillnets in the East Sea from January to December 2003. Monthly changes of maturity observed with the naked eyes for females showed that maturing Pacific cod appeared from August, and their numbers increased to $83\%\;and\;100\%$ in November and December, respectively. In January, mature and spawning Pacific cod were observed for the first time and composed over $40\%$ of the population. In February, the proportion of spawning individuals increased to over $50\%$, however, the mature individuals decreased to less than $10\%$. In March, mature fish were not found, and all were in an immature (spent) or spawning state. From April to July all fish remained in immature condition. The males maintained this trend with the females, whereas, mature males appeared from November to March. Monthly changes in the gonadosomatic index (GSI) of females and males showed higher values both in January and February and declined sharply in March. The lower value remained until October and then began to increase from November for the female population. For the males, however, this value remained lower until August, and then began to increase from September, and showed higher values in October through December than in January and February. These results indicated that the spawning season of Pacific cod was from December to March, and the main spawning season was from January to February, and the period of the spawning season was longer for males than the females. The diameter of the matured oocytes was 0.80-1.10 mm with a single mode of 0.95 mm. Fecundity was 1,300,000-9,400,000 in total length of 65-95 cm and the relationship between the total length (TL, cm) and fecundity (Fc) was Fc= $180,248\timesTL-10,883,638$. The total length at first maturity was observed at 57 cm for females and 47 cm for males. The size at $50\%$ group maturity was estimated to be 63.9 cm for females and 56.0 cm for males.

• 한국어류학회지
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• 제20권4호
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• pp.263-271
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• 2008

본 연구는 우리나라 동해안에 서식하는 기름가자미(Glyptocephalus stelleri)의 성숙과 산란에 관한 연구로, 2005년 5월부터 2008년 9월까지 동해구기선저인망어업에 의해 어획된 시료를 구입하여 조사를 수행하였다. 암컷의 GSI 값은 12월부터 증가하기 시작하여 3~5월에 높은 값을 보였고, 6월 이후 감소하기 시작하였으며, 수컷도 암컷과 유사한 경향을 보였다. 따라서 생식소 발달과정 및 생식소 숙도지수의 월 변화로부터 기름가자미의 산란기는 3~6월, 주 산란기는 4~5월인 것으로 추정되었다. 난소의 생식주기는 미숙기(7~11월), 중숙기(12~2월), 완숙기(3~4월), 휴지기(5~6월)로 구분되었다. 포란수는 최소 15,146개(TL 24.1 cm)에서 최대 101,491개(TL 38.1 cm)로 계수되었고, 전장(TL)과 포란수(F)와의 관계식은 $F=0.0004TL^{3.449}$ ($R^2=0.663$)으로, 체장이 커질수록 포란수가 증가하는 경향을 나타내었다. 산란에 참여하는 암컷의 성숙체장은 25.6 cm로 추정되었다.

• 수산해양기술연구
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• 제57권1호
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• pp.78-91
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• 2021

This study analyzed the reproductive biology, fishing characteristics and changes in fishing business of Liparis tanakae, snailfish collected from September to March. It was the period when they were mainly caught from 2018 to 2020. The average length was generally small in September and October and was large in January and February. The average body weight was generally around 1,500 g and the average body weight in autumn was lower and in winter was higher. The sex ratio of male and female was 0.40:0.60 (��2 test, p < 0.05). The spawning period was estimated from October to February and the main spawning period was from December to February through the GSI. The egg diameter of matured staged female L. tanakae was 0.11-1.48 mm, which was the main spawning period and the relationship between body weight and fecundity was F = 1849TL0.1093 (r2 = 0.2401). The monthly catch of L. tanakae was high from November to February, the time of migrating to the coastal area. Coastal gillnet fishery showed the highest percentage of all fisheries catching Liparis spp. Liparis spp. were caught at a high rate in winter in Chungnam, Jeonbuk, Jeonnam and Gyeongnam region, and revenue and cost was increased since 2017. Assuming a situation where there is no catch of Liparis spp., the fishing profit that can be obtained was the highest in Gyeongnam region and the dependence on fishing of Liparis spp. by coastal gillnet fishery was high.

• 한국패류학회지
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• 제26권4호
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• pp.261-265
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• 2010

개조개 표본은 동중국해의 진해만에서 잠수선에 의해 어획된 것을 2002년 1월부터 12월까지 매월 120개체씩 채집된 것이다. 생식소 발달단계는 비활성기 (11월-12월), 초기활성기 (11월-이듬해 1월), 후기활성기 (12월-이듬해 2월), 성숙기 (2월-5월과 10월), 산란기 (4월-12월) 등 5단계로 구분되었다. 주산란시기 6월부터 8월까지이었다. 성숙각장은 71-85mm로 추정되었다. 암컷과 수컷 성비는 유의한 차가 없었으므로 1:1이었다.

• Fisheries and Aquatic Sciences
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• 제10권2호
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• pp.74-85
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• 2007

Pacific anchovy (Engraulis japonicus) eggs were collected during the spawning season (2000-2003) using a revised ring net in the coastal waters adjacent to the Geum River Estuary in the West Sea of Korea (Yellow Sea). Anchovy eggs were present from May to September, showing a peak in spawning from June to July when the water temperature and salinity were $17-27^{\circ}C$ and above 30.00 psu, respectively. During the main spawning season, no clear diel cycle (regarding the 24-h sampling period of dusk, night, dawn, and daytime) was detected in the vertical distribution of anchovy eggs near Eocheong Island (50-60m depth). Judging from the developmental stages of the collected eggs, it appeared that anchovies spawned mostly at night and that the eggs hatched at dusk and during the night. The density of anchovy eggs was high in the southwest-northeast direction in June, and spawners appeared to move offshore in July. Mean egg density was higher in June 2002 than in June 2003 when water temperatures and salinities were lower. This study on the spatiotemporal distribution of eggs will contribute to developing management plans for the Pacific anchovy in Korea.

• 한국어류학회지
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• 제22권2호
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• pp.83-89
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• 2010

본 연구는 우리나라 남해안에 서식하는 문치가자미(pleuronectes yokohamae)의 성숙과 산란에 관한 연구로, 2006년 5월부터 2007년 4월까지 경남 남해군 연안 호망어업과 연안자망에서 어획된 것을 무작위로 채집하여 조사하였다. 암컷의 생식소 발달과정 및 생식소 중량지수의 월 변화로부터 문치가자미의 산란기는 11~2월, 주 산란기는 12~1월로 추정된다. 전장(TL)과 포란수(F)간의 관계식은 $F=3.656TL^{3.518}$ ($R^2$=0.872)이며, 체장이 커질수록 포란수도 증가하는 경향을 보였다. 산란에 참여하는 50% 성숙체장은 전장 19.8 cm이었다. 전 조사기간에 대한 성비(암 수)는 55.2:44.8로 암컷이 우세하였고, 체급별 성비는 전장 25 cm 이하에서는 수컷의 비율이 높았으나 체장이 커질수록 암컷의 비율이 증가하여 32 cm 이상에서는 전 출현개체수가 암컷이었다.

• 한국어류학회지
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• 제18권4호
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• pp.363-367
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• 2006

2003년 4월부터 2004년 3월까지 우리나라 동해안 강원도 양양군 현남면 남애리 연안에서 어획된 참가자미를 대상으로 성숙과 산란에 관한 연구를 수행하였다. 암컷의 생식소 발달과정 및 생식소중량지수의 월 변화로부터 참가자미의 산란기는 2~5월, 주 산란기는 3~4월로 추정된다. 전장 (TL)과 포란수 (F)간의 관계식은 $F=11.307TL^{2.628}$으로 체장이 커질수록 포란수도 증가하는 경향을 보였다. 산란에 참여하는 군성숙체장은 전장 17.8 cm이었고, 이때의 연령은 3세이었다. 전 조사기간에 대한 성비 (암 수)는 60.2 : 39.8로 암컷이 우세하였고, 체급별 성비는 전장 17 cm 이하에서는 수컷의 비율이 높았으나 체장이 커질수록 암컷의 비율이 증가하여 27 cm 이상에서는 전 출현개체가 암컷이었다.