• Ocean and Polar Research
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• 제38권1호
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• pp.21-33
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• 2016

Gametogenesis of the comb pen shell, Atrina pectinata (Linnaeus, 1767) (Bivalvia: Pinnidae) on the southern coast of Ulleungdo Island, Korea was assessed monthly (November 2013 to October 2014) using histology. Gametogenesis commenced in January when the surface water temperature was $12.6^{\circ}C$ and pen shells evidenced an early development phase with small oogonia from January to April, although few females exhibited ripe eggs in their follicular epithelium. In April, the oocyte diameter increased rapidly, and fully mature eggs appeared in May. First spawning males and females were observed in June as the surface water temperature reached $19.3^{\circ}C$ and July ($23.2^{\circ}C$) respectively. The spawning activity continued until the end of September. Histology indicated that the spawning peak of the females in Ulleungdo Island was July to August. During October to January, most of the pen shells were in spent and resting stages. Our data suggested that A. pectinata is a summer spawner, and their annual gametogenesis is closely associated with the seasonal variation in the surface water temperature. The present study is the first provided fundamental information on the life history of A. pectinata in Ulleungdo Island, and this can be put to good use in the management of this pen shell in the study area.

• 한국양식학회지
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• 제16권3호
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• pp.179-186
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• 2003

본 연구는 2002년 2월부터 2003년 1월까지 군산 내항과 충청남도의 서천군 장항읍과 전라북도의 군산시를 연계한 금강하구둑 유역에서 채집된 웅어 , Coilia nasus를 대상으로 산란기를 추정하기 위해 생식소중량지수(GSI), 생식소 발달단계에 따른 생식주기를 조직학적 관찰에 의해 조사하였다. 웅어는 자웅이체이고 난소는 한 쌍의 낭상구조를 하고 있으며 수많은 난소소엽으로 구성되어 있다. 그리고 정소는 한 쌍의 엽상 구조를 하고 있으며 수많은 정소소엽으로 이루어져 있고 후부의 저정낭에 연결되어 있다. 암ㆍ수의 생식소중량지수(GSI)의 월별 변화는 4월에 GSI값이 증가되기 시작하여 난소와 정소가 성숙되고 고수온-장일장이 되는 하계의 6월에 최대에 이른다. 생식주기는 암컷의 경우, 초기성장기(2~3월), 후기성장기(3~4월), 성숙기(5~6월), 완숙 및 산란기(6~7월),회복 및 휴지기(7~l월)의 연속적인 5단계로 구분되었고, 수컷의 경우는 성장기(2~4월), 성숙기(5~7월), 완숙및 방정기(6~7월),회복 및 휴지기(7~l월)의 연속적인 4단계로 구분할 수 있었다. 산란기 난경 빈도분포에 의하면, 웅어는 연중 한번의 산란기를 가지며 한 개체가 최소한 2~3회를 산란하는 다회산란종으로 추정되었다.

• 생명과학회지
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• 제34권2호
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• pp.122-127
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• 2024

본 연구는 우리나라 제주 연안에 출현하는 붉은메기(Hoplobrotula armata)의 산란 및 기초생태에 관한 연구로 2019년 2~12월부터 2020년 2~12월까지 저층트롤 어업에 의해 어획된 시료 총 2,364개체를 대상으로 하였다. 조사결과 체장 22.0~68.8 cm, 체중 66.5~3,553.9 g 범위로 나타났다. 생식소 숙도지수(Gonadosomatic index) 및 발달과정 분석 결과 주 산란기는 암·수 전부 7~10월로 나타났다. 전장과 체중의 상관관계를 조사하였을 때 암컷 BW=0.0024TL^3.3278, 수컷 BW=0.0035TL^3.2162으로 나타났으며, 개체군의 성장이 양호한 것으로 나타났다. 조사기간에 대한 성비는 1:0.71으로 암컷이 수컷보다 우세하였다. 산란에 참여하는 붉은메기의 50%, 75%, 97.5% 성성숙 전장은 암컷의 경우 각각 39.9 cm, 42.7 cm, 49.4 cm로 나타났으며 수컷은 37.6 cm, 40.4 cm, 46.9 cm으로 나타났다. 제주 연안에 출현하는 붉은메기는 GSI 및 월별 생식 세포 발달 단계 결과, 연 1회 산란하는 하계 산란형(Summer spawner)으로 추정된다.

• 한국어류학회지
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• 제29권1호
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• pp.80-86
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• 2017

본 연구는 남해 중부 연안역에서 2016년 4~8월까지 자어군집구조의 월 변화를 조사하였다. 조사기간 동안 총 42종의 자어가 출현하였다. 우점종 중 멸치(E. japonicus)는 여름보다는 봄철에 우점하였고, 용서대(C. abbreviates)는 봄철에만 출현하였으며 수조기(N. albiflora)는 여름철에만 출현하였다. 자어 군집은 계절별로 4~5월 (봄)과 6~8월 (여름)의 그룹으로 유의하게 나눌 수 있었고, 여름철은 또다시 6~7월과 8월의 두개의 유의한 그룹으로 나눌 수 있었다. 2016년 8월 조사해역에서는 이상 고수온 현상이 발생하여 표면수온이 $28^{\circ}C$까지 상승하였고, 멸치와 수조기 자어의 출현량은 산란 적정수온을 넘은 수온으로 인해 급감하였다.

• 한국해양학회지
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• 제18권2호
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• pp.161-168
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• 1983

淺水灣에 書式하는 전어의 體長, 年齡 및 成熟度를 分析하여 年齡造成과 繁殖期에 대하여 考察하였다. 資料는 1981年 5月부터 1982年 12月 사이 灣入口에서 小型定置網으로 收集하였다. 전어는 봄에 水溫이 8$^{\circ}C$ 程度로 上昇하였을 때 灣으로 들어 온다. 여름 동안 이곳에서 자란 후, 가을에 水溫이 8$^{\circ}C$ 以下가 되기 전에 灣을 빠져 나간다. 전어는 태어난 첫해에 가장 빨리 자라며, 1-4歲群의 平均體長은 각각 12.2, 15.8, 17.6 및 20.9cm 이었다. 觀察된 가장 큰 個體는 22.0cm었고 나이는 4歲 이었다. 淺水灣 전어는 태어난지 2年이 지나면 夙成되며, 이때 體長은 14cm에 이른다. 成熟年齡과 體長을 分析한 缺課 전어의 成熟은 年齡에 의하여 決定되지 않고 體長에 左右됨이 밝혀 졌다. 전어는 水溫이 8-15$^{\circ}C$인 4月末에서 5月末 사이 産卵한다.

• 수산해양기술연구
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• 제54권3호
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• pp.262-270
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• 2018

We examined the characteristics of egg and larval distributions and catch changes of anchovy in relation to abnormally high sea temperature in the South Sea of Korea in summer 2015 and 2016. The densities of anchovy eggs and larvae in the southern coastal region were lower in July-August 2016 than in July-August 2015. In particular, anchovy eggs and larvae (approximately 5 mm TL) were rarely observed in the coastal region in August 2016 due to the abnormally high SST (up to $28^{\circ}C$), which was above the optimum spawning temperature of anchovy. The catch of non-swimming stage (< 2 cm TL) larval anchovy was lower in July-August 2016 than in July-August 2015. The decreased catch of larval anchovy in July-August 2016 could be attributed to decreased spawning density in June-July 2016. In contrast, the catch of swimming stage (> 2 cm TL) anchovy was increased in July-August 2016. In the summer of 2016, prominent sea temperature near the southern coast of Korea and sea temperature higher than $30^{\circ}C$ in the offshore region of the South Sea of Korea could greatly enhance the retention of swimming anchovies in the coastal fishing grounds.

• 수산해양기술연구
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• 제54권1호
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• pp.81-88
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• 2018

A study for species composition and abundance of the fish assemblages in the eastern Jinhae Bay, Korea was conducted using monthly larval collection by a RN80 net from October, 2010 to September, 2011. Of all the 45 species collected, the dominant species were Clupea pallasii, Hexagrammos otakii, Pholis fangi and Engraulis japonicus. Clupea pallasii, Hexagrammos otakii, Pholis fangi in winter and examined Engraulis japonicus, Acanthogobius sp., Parablennius yatabei, and Tridentiger trigonocephalus in summer appeared seasonally. Popoulation characteristic by stations was not clear seasonally and spatially, and appearance aspects of dominant species were similar by stations. Compared our results with other studies in the South Sea, dominant species and their appearance period were similar to their spawning period. Finally, the appearance period of the larvae in the South Sea was closely resulted to spawning period rather than the regional characteristic.

• 한국수산과학회지
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• 제36권2호
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• pp.120-128
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• 2003

Fishes were caught by a set net in the coastal waters off Yosu, Korea from April to October, 2001, and seasonal variation of abundance and species composition were studied. Fifty two species were identified as fish $(89\%)\;cephalopods\;(10\%)\;and\;crustaeans\;(1\%).$ Of the fishes Engraulis japonicus, Trachurus japonicus and Trichiurus lepturus were dominant species representing $64.1\%$ in total number of individuals. The number of species was high in spring and low in summer; number of individuals was high in spring and low in autumn. The diversity index (H') was 0.4-0.7 The abundance and species composition fluctuated seasonally. Occurrence of the various stages of fishes indicated that Scombia japonicus, T. japonicus and E japonicus utilized in the area as spawning ground, Conger myriaster larvae, Ammodytes personatus and Seriola quinqueradiata as nursery ground, and T. lepturus and Ilisha elongata as spawning and nursery grounds.

• 한국수산과학회지
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• 제54권4호
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• pp.498-507
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• 2021

Ichthyoplankton (fish eggs and larvae) were collected seasonally collected from 2017 to 2019 to clarify whether Dokdo serves as a fish spawning and/or nursery ground. Fish eggs were identified and classified into 16 species. The dominant fish egg species were Engraulis japonicus, Maurolicus japonicus, and Parajulis poecilepterus. Fish larvae were identified and classified into 15 species. The dominant fish larvae species were E. japonicus, M. japonicus, and Sebastes owstoni. A cluster analysis similarity percentages revealed two distinct groupings according to sample location (stations) with E. japonicus and M. japonicus as the main group influencers. E. japonicus was the dominant species off Dokdo. The species diversity and abundance peaked in summer. The diversity index, richness index, and evenness index fluctuated seasonally. There were no predominant species variations among the years. Sedentary species such as P. poecilepterus, Semicossyphus reticulatus, and Glyptocephalus stelleri occurred in the inshore stations. E. japonicus, M. japonicus, and Trachipterus trachypterus occurred in the offshore stations. Our results show these species use Dokdo as spawning and nursery grounds.

• 한국수산과학회지
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• 제47권1호
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• pp.59-61
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• 2014

We conducted eight surveys in the northern East China Sea (ECS) in winter (February - April), summer (July), and autumn (October) 2004-2009, to investigate the seasonal distribution of T. pacificus. A total of 482 paralarvae, ranging in mantle length (ML) from 1.0 - 17.0 mm, were collected at 73 out of 181 stations. There were higher numbers of paralarvae during the winter and summer months than in the autumn. There was significant seasonal variation in the paralarval mantle lengths; mantle lengths were longer in winter (April) than in summer (July). The position of oceanic fronts in the study area played an important role in restricting paralarval distribution along the inshore edge of the Tsushima Warm Current (TWC). When the TWC expanded to western Jeju Island in winter and autumn, the paralarval distribution range extended to include western Jeju Island. However, when the TWC was located southeast of Jeju Island in the summer, paralarvae were distributed along the frontal zone off southeast Jeju Island. Sites at which paralarval mantle length was <2.0 mm ML indicated that the spawning ground were likely to be within the northern ECS in winter and summer, but north of the study area in autumn.