• 한국양식학회지
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• 제4권2호
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• pp.85-95
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• 1991

1989년 6월 1일부터 1990년 1월 5일까지 189일간 수온과 광주기를 조절하여 넙치의 산란을 유도한 결과를 요약하면 다음과 같다. 수온 조절에 의한 최초의 산란은 최저수온 $10.6^{\circ}C$ 설정후 수온 $13^{\circ}C$ 전후인 60일 만에 산란이 시작되었고, 자연수의 수온을 낮추기 시작한 때로 부터는 76일이 소요되었다. 한편 광주기 조절에 의한 산란은 수온 $13^{\circ}C$ 전후에서 광주기가 10L/14D로 될 때부터 장일처리를 시작하여 14L/10D로 전환되는 시기에 산란이 이루어졌으며, 장일처리개시일로부터는 71일이 소요되었다. 전 산란기간은 94일이었으며, 그 중 산란이 이루어진 일수는 69일이었다. 산란기간중 1일 최대 산란양은 $133.2{\times}10^4$입 이었으며, 1마리의 평균 산란양은 $267.1{\times}10^4$입이었다. 산란 기간은 산란 전기 30일, 산란중기 41일, 산란후기 23일의 3단계로 구분되었다. 총산란양에 대한 부상란 수와 수정률은 서로 비예하는 경향이었고, 평균 수정률은 중기가 $54.1{\%}$로 가장 좋았고, 전기 $37.4{\%}$, 후기 $19.6{\%}$ 순이었으며, 전체 평균은 $44.4{\%}$였다. 한편, 사료섭식량과 산란과의 관계는 성숙이 진행되는 시간에는 섭식량이 증가하다가 산란개시시부터는 급격히 감소하였으며, 산란 종료시에는 더욱 감소하는 경향을 나타내었다.

• 수산해양교육연구
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• 제29권2호
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• pp.447-452
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• 2017

A closely associated set of characteristics was analyzed using both classical and truss dimensions to discriminate sexual dimorphism between spawning season and non spawning season in grass puffer, Takifugu niphobles. In non-spawning season, $1{\times}10/Ls$ of classical dimension was significantly different between male and female (P<0.05). In spawning season, $1{\times}9/Ls$ and $1{\times}10/Ls$ of classical dimension, $3{\times}8/Ls$, $3{\times}9/Ls$, $3{\times}10/Ls$, $4{\times}8/Ls$, $4{\times}9/Ls$ and $8{\times}9/Ls$ of truss dimension and $7{\times}9/HL$ of head part dimension were significantly different between male and female (P<0.05). The results of this study may be useful as basic information of other fish species to compare the change of sexual dimorphism between spawning season and non spawning season.

• 한국패류학회지
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• 제19권2호
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• pp.107-110
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• 2003

The effect of broodstock age on the spawning performance of cultured abalone, Haliotis discus hannai, was assessed for five age groups (3, 4, 5, 6, 7 years old). Spawning performance of the five age groups was assessed in terms of the percentage of spawning abalone, eggs per spawning female, fertilization rates, hatch rates and attachment rates per spawning. The percentage of spawning abalone increased along with broodstock age, reached maximum in female groups of 5- and 6-year age (60%), and in male group of 6-year age (100%), subsequently decreased in 7-year age group. The number of eggs produced per spawning also increased with broodstock age, and the maximum was found in 6-year age. Although the number of spawned eggs for the oldest abalone declined, it still spawned much more eggs than 3, 4, and 5 years old females. The fertilization and hatch rates were obviously larger for 4-6 years old group than the younger and older abalones. The maxima were found in 5-year age group (96.0% and 84.5%), and the minimum were appeared in 7-year age group (79.3% and 58.2%). The attachment rate increased with broodstock age, reached maximum in 6-year age group (33.6%), although the increment gradually declined. The attachment rate for 7-year age group rapidly decreased (16.6%). These results suggested that broodstock age affected the spawning performance of H. discus hannai, which peaked between 5 and 6 years old, and broodstock should be bred during this period for hatchery production.

• 수산경영론집
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• 제51권4호
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• pp.19-45
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• 2020

This study is to evaluate economic effect of the creation project of snow crab, Chionoecetes opilio, spawning and habitat ground in Uljin and Youngdeok county. The main results of this study are summarized as follows: first, 14,400 million won was invested in the creation project cost of Chionoecetes opilio spawning and habitat ground of Uljin and Youngdeok County from 2015 to 2020. Second, the creation project of Chionoecetes opilio spawning and habitat ground directly provides fishing benefits, festival benefits, research and development benefits and employment benefits. Third, on the basis of above benefits, the creation project of Chionoecetes opilio spawning and habitat ground has net present value of 29,900.53 million won, internal rate of return 16.9%, and benefit-cost of 2.91 under a 4.5% social discount rate. Also, the creation project creates 195 jobs. This indicates that the creation project of Chionoecetes opilio spawning and habitat ground not only contributes to the increase in the income of coastal fishery and fishing villages but also to the job making. The result of this study provides useful information to policy makers or project managers as it shows that the project to create spawning and habitat ground should be carried out in consideration of the resource and biological characteristics of individual fish and that economic assessment logic should also be developed based on this. Also, it proves that the project to create a snow crab spawning and habitat ground is a national and local infrastructure project that increases the actual fishing income in the region. At the same time, it maintains the reproducibility function of most fish species, along with enhancing the people's benefits such as fishing village tourism and marine product consumption. Moreover, it provides useful information on budgeting for the continuous development of snow crab spawning and habitat ground in the mid to long-term.

• Fisheries and Aquatic Sciences
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• 제7권3호
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• pp.136-140
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• 2004

We examined the ovaries of 312 robust tonguefish (Cynoglossus robustus) collected each month from January to December 2001, off the coast of Yeosu, Korea. The samples were used to investigate robust tonguefish reproductive activity. Monthly changes in the gonadosomatic indexindicated that spawning peaked between June and August. Fish size at first spawning was 15-19 cm total length (TL). Over $50{\%}$ of female fish 25-29 cm TL were sexually mature, and this rose to $100{\%}$ for female fish 35-39 cm TL. The tonguefish spawned four or more times during the spawning season. Most females commenced spawning in their second year. The relationship between total length (cm TL) and fecundity (F) was F=528646Ln(TL)-1E+06.

• 한국어류학회지
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• 제26권1호
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• pp.11-16
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• 2014

2009년 5~7월까지 전북 진안군 주천면 주양리에 위치한 주자천에서 감돌고기의 일중 산란 타이밍 및 초기 산란위치에 대한 연구를 실시하였다. 감돌고기의 산란은 5월 7일부터 7월 11일까지 이루어졌으며 꺽지 산란장에만 탁란을 했다. 61개 꺽지 산란장 중 56개의 산란장에 탁란했으며, 꺽지 산란 후 1~2일 사이에 시작되었다. 하루 중 감돌고기의 탁란은 꺽지의 공격횟수가 낮게 나타난 6~7시 사이에 가장 높은 빈도로 관찰되었다. 감돌고기가 탁란한 알의 부화율은 지속적인 꺽지의 산란장 방어와 가장 밀접한 상관관계를 나타냈으며, 감돌고기는 자신의 알을 중심으로 난 보호를 하는 꺽지 난괴와 가까운 곳부터 산란을 함으로써 꺽지의 난 보호를 통한 이득을 얻는 것으로 생각된다.

• 한국수산과학회지
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• 제23권6호
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• pp.425-438
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• 1990

쉘리코프 해협에서 산란하는 명태의 정확한 산란장소 및 시기를 조사하기 위하여 1981 년, 1984년, 1985년에 음향학적 조사 및 난치자어 조사를 하였다. 알라스카만의 명태는 산란하기 위하여 늦겨울 내지 초봄에 쉘리코프 해협으로 이동한다. 명태는 대륙사면으로 부터 따뜻하고 염분도가 높은 해수를 이용하여 해협 남동쪽 입구의 바닥을 타고 들어와 중앙부의 서쪽면에 있는 깊은(>200 m) 곳에 모여들고, 3월부터 산란을 한다. 최대산란은 이곳에서 3월 하순부터 4월 초순에 걸쳐 일어나고, 해협내 수괴의 성질(해수온, 염분도, 밀도 등)은 해마다 다르지만 산란시기 및 장소는 거의 변함이 없다. 이 해역은 어류의 산란장이 보육장과 가까이 있다는 지리적 이점 이외에도 해마다 이 시기에는 해수의 이동량이 최저치로 내려가고 식물플랑크톤 번식의 핵심요소인 해수의 표면 혼합층이 최소로 된다는 해양학적 현상 때문에 알라스카만 명태의 최적합 산란장이 되어왔다고 추측된다. 4월 초순 이후, 산란행위는 급격히 감소하며 산란장은 북동쪽과 남서방향으로 약간 확장됨을 보여준다.

• 수산해양기술연구
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• 제45권4호
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• pp.234-242
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• 2009

To develop the artificial spawning seaweeds of the sandfish, Arctoscopus japonicus, the effects by the material type of artificial spawning seaweeds were investigated at Dongsan port in Gangwon-do from December 2006 to March 2007. Sargassum fulvellum, S. horneri, rope and net were used as materials for artificial spawning seaweeds, and the most effective thing among them was S. fulvellum. A. japonicus began to attach the egg mass to artificial spawning seaweeds when sea temperature dropped below 10${^{\circ}C}$ in December, spawned heavily when it was around 8${^{\circ}C}$ in January, and completed the behavior when it started to increase over 10${^{\circ}C}$ in February. The hatching period of eggs was estimated to be about 60 days. The middle position in artificial spawning seaweed had the highest number of egg masses and the diameter of the egg mass ranged from 25mm to 62mm. Based on the result for the effects, the artificial spawning seaweeds of A. japonicus were developed and it is possible to use them to form seaweed forests or spawning grounds of other species.

• 한국수산과학회지
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• 제52권5호
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• pp.534-538
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• 2019

The distribution and characteristics of spawning beds of the Pacific herring Clupea pallasii, were observed by scuba diving in Jinhae Bay, Korea, with a focus on marine vegetation as adhesive substrates and egg density during the spawning season. In 2017, the fertilized eggs of C. pallasii were mainly found attached to the leaves of algae species Carpopeltis cornea, Gracilaria textorii, and Acrosrium polyneurum at the rocky shore in Wonpo-dong and Jeodo. The mean density of fertilized eggs in C. pallasii spawning beds was $153,776eggs/m^2$ off Wonpo-dong and $856,430eggs/m^2$ off Jeodo, giving an estimated total of $5.345{\times}10^9$ eggs in Wonpo-dong and $3.3074{\times}10^{10}$ eggs in Jeodo. We examined spawning beds with an area of $38,619m^2$ off Wonpo-dong and $34,760m^2$ off Jeodo. The choice of spawning bed may be affected by the composition of marine vegetation, such as the algal diversity of rocky shore environments, which could affect adhesive substrates and egg density during the spawning season. The results of the present study suggest that the spawning season of C. pallasii in Jinhae Bay is in January to mid-February.

• 한국수산과학회지
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• 제42권5호
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• pp.481-486
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• 2009

In 2007, 43.5% mortality of the cultured oyster population occurred in Gamak Bay. Mortality rapidly increase in September and peak in October. To prevent future mass-mortality event, we investigated spawning and variation of oyster body composition. The main spawning period of culture oyster occurred from August to September. Condition index and body composition (protein and glycogen) appeared to be influenced by the spawning activity. Condition index and glycogen content in September were lowest (13.5% and 5.6 mg/g, respectively). However, protein, lipid and glycogen contents did not rapidly recover after the spawning activity. The data indicates that mass-mortality of cultured oysters in Gamak Bay may be due to deteriorated health, spawning activity, stress of the high water temperature and decreasing food resources.