• 한국패류학회지
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• 제29권1호
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• pp.65-76
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• 2013

We investigated the gametogenic cycle and spawning seasons of the male Chlamys (Azumapecten) farreri nipponensis by qualitative and quantitative analyses, and also the size at 50% of group sexual maturity was calculated by the data of first sexual maturity. In this study, the male gametogenic cycle of this species by qualitative analysis was divided into five successive stages: early active stage (January to March), late active stage (March to April), ripe stage (April to August), partially spawned stage (July to September), and spent/inactive stage (August to January). The male gametogenic cycle showed similar patterns with monthly changes in the gonadosomatic index and condition index. Particularly, spawning in male scallop occurred once a year from July to September, unlike the spawning period of this species (from June to August) reported by the previous researchers. In quantitative statistical analysis using an image analyzer system, the patterns of monthly changes in the percent (%) of the areas occupied by spermatogenic stages to the testis areas in males showed a maximum in June, and then sharply dropped from July to September, 2006. From these data, it is apparent that the spawning season of C. (A.) farreri nipponensis occurred once per year from July to early September, indicating a unimodal gametogenic cycle during the year. Shell heights at 50% of group sexual maturity (RM50) fitted to an exponential equation were estimated to be 49.90 mm in males (considered to be one year old), and it was 100% for male scallops over 61.0 mm (considered to be two years old).

• 한국어류학회지
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• 제29권2호
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• pp.109-116
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• 2017

본 연구는 우리나라 주요 수산자원 중 하나인 민어의 성숙과 산란을 추정하였다. 연구에 사용된 민어는 2015년 8월부터 2016년 12월까지 우리나라 서해 남부 연안에서 안강망으로 어획되어 양육된 것으로 총 453개체 중, 암컷 229개체, 수컷 211개체를 사용하였다. 성숙도와 생식소숙도지수의 월 변화 결과 민어의 산란기는 8~10월, 주산란기는 9월로 추정되었다. 50% 이상 개체가 생식 가능한 군성숙도를 살펴본 결과 암컷의 군성숙전장은 54.8 cm, 수컷은 49.0 cm로 조사되었다.

• 한국해양생명과학회지
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• 제7권1호
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• pp.37-44
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• 2022

연구는 기름가자미의 성비, 군성숙도 및 주 산란기에 관한 정보를 얻기 위해 수행하였다. 성비(암:수)는 1:0.54 (n=189:103, 암컷 64.7%)였으며, 전장이 증가함에 따라 암컷의 비율이 높아지는 경향을 보였다. 난모세포 발달패턴은 동일 난소 내에서 여러 단계의 난모세포군이 확인되는 난군동기발달형이었다. 로지스틱 회귀모델에 의해 분석된 50% 성숙 전장은 암, 수 각각 28.51 cm과 30.49 cm였다. GSI는 암, 수 각각 4월과 3월에 가장 높았으며, 주 산란기는 4-5월로 분석되었다.

• 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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• 제21권2호
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• pp.81-93
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• 2005

Reproductive cycle with the gonadal phases, first sexual maturity, artificial spawning amount by the size and spawning interval of the hard clam, Meretrix lusoria were investigated by histological observations and morphometric data by artificial spawning induction. Meretrix lusoria is dioecious and oviparous. The reproductive cycle of this species can be classified into five successive stages: early active stage (January to March), late active stage (February to May), ripe stage (April to August), partially spawned stage (June to September), and spent/inactive stage (September to February). The spawning period was from June to September, and the main spawning occurred between July and August when the seawater temperature exceeds over $20^{\circ}C$. Percentage of first sexual maturity of female and male clams ranging from 40.0 to 45.0 mm in shell length was over 50%, and all clams over 50.0 mm in shell length sexually matured. Female and male clams ranging from 40.0 to 45.0 mm in shell length are considered to be two years old. Therefore, we assume that the hard clams of both sexes begin reproduction from two years of age. The mean number of the spawned eggs increased with the increase of size (shell length) classes. In case of artificial spawning induction, the number of spawned eggs from the clams of a sized class was gradually decreased with the increase of the number of the spawning frequencies (the first, second, and third spawnings). In the experiments of artificial spawning induction during the spawning season, the interval of each spawning was estimated to be 15-18 days (average 17 days).

• 한국어류학회지
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• 제36권3호
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• pp.253-262
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• 2024

이번 연구는 서해 중부해역에 서식하는 넙치(Paralichthys olivaceus)의 성숙도, 생식소숙도(GSI), 산란기, 성숙체장을 구하였다. 넙치 암컷의 생식소숙도지수 (GSI) 값은 5월에 가장 높았고, 산란기는 4월에서 6월로 나타났다. 넙치 수컷의 생식소숙도지수 (GSI) 값은 3월에 가장 높게 나타났으며, 산란기는 3월에서 6월로 추정되었다. 넙치 암컷의 50.0% 성숙체장은 49.4 cm이고, 수컷은 36.5 cm 로 분석되었다.

• Fisheries and Aquatic Sciences
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• 제13권4호
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• pp.332-339
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• 2010

Maturity and spawning of the snailfish, Liparis ochotensis was investigated based on samples collected by gill net in the East Sea of Korea from December 2008 to December 2009. The average total length of L. ochotensis was 63.4 cm and 64.1 cm for females and males, respectively. Gonadosomatic index (GSI) began to increase in July, reaching a maximum in November, then began to decrease in December. Monthly changes in the GSI values of L. ochotensis were similar for females and males. Annual reproductive cycle of this species can be divided into five successive stages in females: early growing stage (May), late growing stage (June to July), mature stage (August to September), ripe and spent stage (September to December), and recovery and resting stage (January to April). Males show four successive stages; growing stage (May to July), mature stage (August to September), ripe and spent stage (September to December), and recovery and resting stage (January to April). Relationship between total length (TL) and fecundity (F) was F=$0.00003TL^{4.002}$ ($R^2$ = 0.703), and F increased with TL. Total length at 50% group maturity was estimated to be 55.8 cm. Our findings suggest that the spawning period takes place from September to December, with the main spawning period occurring from October to December.

• 한국패류학회지
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• 제21권1호
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• pp.1-11
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• 2005

Reproductive cycle, first sexual maturity, spawning amount related with the size and spawning interval in female Ruditapes philippinarum were investigated by histological observation and the analysis of morphometric data during artificial spawning induction. Ruditapes philippinarum is dioecious and oviparous. The reproductive cycle of this species can be subdivided into five successive stages: early active stage (January to March), late active stage (February to May), ripe stage (April to August), partially spawned stage (May to October), and spent/inactive stage (August to February). The spawning period was once a year between May and early October, and the main spawning occurred between July and August when seawater temperature was approximately $20^{\circ}C$. Percentages of first sexual maturity of female clam of 15.1-20.0 mm in shell length were 56.3%, and 100% for the clams > 25.1 mm. The mean number of the spawned eggs increased with the increase of size classes (shell length). In case of spawning induction by the same size class, the number of spawned eggs were gradually decreased with the increase of spawning frequencies (the first, second, and third spawnings). In the experiments of artificial spawning induction during the spawning season, the interval of each spawning was estimated to be 15-17 days (average 16.5 days).

• 한국수산과학회지
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• 제53권1호
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• pp.36-42
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• 2020

The maturation and spawning of white crocker Pennahia argentatus were investigated using samples collected in the Southern Sea of Korea from January to December 2018. We analysed monthly changes in maturity stage, gonad-osomatic index (GSI), total length (TL) at 50% group maturity. The spawning period was May to July. Fecundity varied between 71,627 and 888,041 eggs. The relationship between the fecundity and TL of the fish was expressd in the fecundity equation as F=0.2198TL^4.2784 (r²=0.8423). The percentage of sexually mature females estimated from a logistic function was over 50% for the size group 19.33 cm (total length, TL).

• 수산해양기술연구
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• 제49권4호
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• pp.449-458
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• 2013

This study investigated purplish Washington clam, Saxidomus purpuratus on its gonadal development, reproductive cycle and shell length (age) at 50% female group maturity from January to December 2011 in Jinhae Bay, Korea. This species is dioecious. The gonad index (GI) began to increase in January, reached the maximum value in May and to decrease in June, reached the minimum value in September then to increase slowly in October again. The reproductive cycle of the clams can be divided into five successive stages: the early active stage (Ea, from February to March), the late active stage (La, from January to March and October to December), the ripe stage (R, from January to May), the spawning stage (S, from June to December) and the degenerative and inactive stage (Ia, from January to February and November to December). The spawning periods were from June to December and the main spawning periods were from July to October. The shell length at 50% female group maturity (SL50) was estimated to be 63.6 mm, which can be converted as sexual maturity age of 2.2 year.