• 한국패류학회지
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• 제30권4호
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• pp.333-342
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• 2014

Ultrastructural studies of oogenesis in oocytes, oocyte degeneration associated with the follicle cells in female Coecella chinensis were investigated for clams collected from Namhae, Geongsangnam-do, Korea. In this study, vitellogenesis during oogenesis in the oocytes occured by way of endogenous autosynthesis and exogenous heterosynthesis. Of two processes of vitellogenesis during oogenesis, the process of endogenous autosynthesis involved the combined activity of the Golgi complex, mitochondria and rough endoplasmic reticulum. whereas the process of exogenous heterosynthesis involved endocytotic incorporation of extraovarian precursors at the basal region of the oolema of the early vitellogenic oocytes prior to the formation of the vitelline coat. It is assumed that the follicle cells were involved in the development of previtellogenic and early vitellogenic oocytes and appear to play an integral role in vitellogenesis in the early and late vitellogenic oocytes by endocytosis of yolk precursors, and also they were involved in oocyte degeneration by assimilating products originating from the degenerated oocytes, thus allowed the transfer of york precursors needed for vitellogenesis (through phagocytosis by phagolysosomes after spawning). Follicle cells presumably have a lysosomal system for breakdown products of oocyte degeneration. and for reabsorption of various phagosomes (phagolysosomes) in the cytoplasm for nutrient storage during the period of oocyte degeneration.

• 한국해양학회지
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• 제11권1호
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• pp.1-8
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• 1976

피조개, Anadara broughtonii(SCHRENCK)는 근년에 와서 산업적 가치가 높아짐에 따라 중요 양식대상종으로 많은 연구의 대상이 되고 있다. 인공 및 천연채묘에 관해서는 관야91963), 이등 외(1967), 금정 외(1969), 전중(1971)등의 연구와 중간양성에 관해서는 관야 외91966)의 연구가 보고되고 있으며 유91969, 1970)는 먹이 및 성장에 관해서 보고한 바 있다. 본고에서는 피조개의 산란 및 유생의 출현상황과 분표에 영향을 미칠것으로 추측되는 몇가지 환경요인을 관찰하여 검토한 결과를 보고한다.

• 한국수산과학회지
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• 제50권3호
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• pp.296-301
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• 2017

We conducted a study to 1) determine the indicators of gonadal maturity in male and female Korean walleye pollock Theragra chalcogramma for the purposes of artificial insemination; 2) establish the RNA/DNA ratio of mature eggs in this species; and 3) monitor the effect of refrigerated storage on egg viability and the motility of sperm collected from dead adult males. During the spawning season, the color of female gonads changed from orange to transparent, and that of male gonads changed from pale orange to milky white. The DNA content and RNA/DNA ratio of mature eggs were maintained without significant changes for approximately 6 h when eggs were preserved at $4^{\circ}C$. Sperm could be obtained from both milt and undiluted semen. Sperm obtained from milt ceased moving on the second day after isolation, while over 60% of sperm obtained from semen showed movement until the 13th day. Seven attempts were made to artificially inseminate mature eggs, of which two resulted in successful fertilization. The successful inseminations produced 94,000 and 5,000 fertilized eggs, respectively. This study shows that artificial insemination of walleye pollock is a viable strategy when natural propagation is not possible.

• 한국수산과학회지
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• 제18권6호
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• pp.581-585
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• 1985

1981년 8월에서 1982년 5월까지 일본 암수현 대퇴만에서 섶 속살이게, Pinnotheres pholadis에 기생된 진주담치를 정기적으로 채집하고 기생군과 비기생군간의 각장에 대한 육중의 상관관계를 조사하고, 그 성숙도와 영양상태의 차를 조직학적 방법에 의해 구명했다. 섶 속살이게의 기생으로 말미암아 진주담치는 증육에 명백한 장해를 받음이 밝혀졌다. 또한, 생식선의 발달이 늦어질뿐 아니라, 생식세포의 수가 감소됨으로써 전체면적에 대한 생식선의 면적비가 낮아지게 되므로, 기생군의 번식력은 비기생군에 비해 현저하게 약한 것으로 추정된다.

• 한국균학회지
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• 제47권4호
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• pp.347-357
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• 2019

본 연구에서는 urushiol 제거에 적합한 장수버섯 종균용 원료에 대하여 평가하였다. 세 가지 곡물조, 현미, 통밀에서의 장수버섯 균사체 증식속도는 각각 4.92±0.05, 2.20±0.03, 1.93±0.03 mm/day 이었다. 장수버섯이 배양된 곡물종균의 laccase의 활성은 각각 0.86±0.02, 0.04±0.01, 0.01±0.00 U/mL 이었다. 증식속도와 효소활성 측면에서 장수버섯 종균용 곡물로는 조를 사용하는 것이 적합하였다. 조에 배양된 장수버섯 종균을 옻나무에 배양하였더니 3일차에 urushiol이 최대 86.6% 감소하였고 7일차에 98.5%까지 감소하였다. Urushiol 제거를 위한 적정 배양기간은 3일이었으며 이때 flavonoid 잔존량은 68%, phenolic 성분의 잔존량은 42% 이었다. 액체종균을 사용하여 배양한 것과 비교했을 때 urushiol을 제거하기 위한 증식기간이 10일에서 3일로 단축되었다.

• 생명과학회지
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• 제19권12호
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• pp.1851-1854
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• 2009

본 연구는 통영 해역에서 채집되어진 갯장어, Muraenesox cinereus의 생식년주기에 있어서 난소 발달과 생식소중량지수 (gonadosomatic index; GSI) 변화에 따른 혈중 estradiol- $17{\beta}$ ($E_2$) 농도 변화를 서로 연관시켜 조사하였다. 난소 성숙도는 조직학적 관찰을 기초로 주변인기(11월-2월), 유구기(3월-4월), 초기 난황형성기(4월-5월) 및 후기 난황형성기(6월-10월)로 나 눌 수 있었다. GSI의 계절적 변화는 수온과 밀접한 연관성을 가지고 있으며, 난소의 성숙 정도에 영향을 미쳤다. 혈중 $E_2$ 농도는 GSI 변화와 관련이 있어 4월에 증가하여 7월에 년중 최고치에 도달하였고 10월까지 비교적 높은 농도로 유지하였다. 이러한 결과들은 GSI와 혈중 $E_2$ 농도 변화는 갯장어 난소 발달과 밀접한 관련이 있음을 나타내고 있다. 그러나 본 연구에서는 산란기의 암컷 갯장어를 채집하지 못하였다. 이러한 이유로 산란기의 개체는 외해의 심해쪽으로 이동하기 때문이라고 추측된다.

• 한국수산과학회지
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• 제35권6호
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• pp.614-620
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• 2002

본 연구는 3년생 양식 가두리산 어미를 실내 수조로 옮긴 뒤 연중 생식소와 호르몬의 주년 변화를 파악하기 2년 동안 매달 샘플을 실시하였다. 형태학적 내분비학적 분석 결과 수컷은 암컷에 비해 앞서 성숙이 진행되고, 산란은 1월말에서 3월 사이에 이루어졌다. 산란기 이후 다음해 1월까지 모든 암컷은 난황형성 이전 단계에 머물러 있었고, 수컷 중 일부는 정자형성 활성을 다시 나타내기 시작했다. 10월에 접어들면서 일조량의 감소와 함께 성장 중인 난모세포에서 cortical alveoli이 나타나기 시작하고, 정자 형성이 점차 늘어났다. 10월과 2월 사이 암컷은 vitellogenesis, 수컷은 spermatogenesis가 일어나며, 난소 성숙지수는 암컷이 4.3$\~$$24.1\%$, 수컷은 $6\%$ 이상으로 증가하였다. 그리고 산란력 평가를 통해 농어는 다른 해산어류와 유사한 산란 전략을 지니고 있었으며, 다회산란의 특성을 지니고 있었다. 또한 농어의 생식기 과정동안에 이루어진 성호르몬인 testosterone (T)과 estradiol-17$\beta(E_{2})$ 의 분석 결과 생식기 발달에 따른 농도의 변화가 있는 것으로 확인되었다. 특히 11월에서부터 2월까지 높은 혈중 T와 $E_{2}$의 농도는 이 시기 수컷의 정자형성과 난소의 성숙란 형성에 있어 이들 호르몬의 관련성이 확인되었다. 이상의 결과로 양식산 농어의 생식기능은 실내 수조에서 발현이 되며, 따라서 인공종묘생산에 필요한 수정란 생산이 실내 수조에서 가능하다고 할 수 있다.

• 한국환경과학회지
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• 제29권8호
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• pp.809-818
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• 2020

To conserve the population of a hesperiid butterfly, Leptalina unicolor, inhabiting the protected areas of Jaeyaksan, we provide ecological information on their behavior and propose habitat conservation measures, such as the creation of alternative habitats based on comprehensive information. The behavioral study used a method of re-capture after releasing the butterfly with enamel marks on the wings. Adult behaviors were shown in four patterns: flying, settling on a plant, nectar absorption, and water absorption. Both males and females had the highest proportion of flight movement overall; however, males had a slightly higher proportion of flight movement. As for duration, females spent more time settling on plants to select spawning sites, and males seemed to take a longer time for water absorption activities, to absorb minerals needed to form the spermatophore. The average travel distance of butterflies was 27.5 m for females and 46.7 m for males, with daily activity ranges from 11.2 m to 43.8 m, and 21.4 to 57.6 m, respectively. The most important condition to preserve the habitat of Leptalina unicolor is to maintain the community of Miscanthus sinensis, a food plant. Additionally, because this butterfly has a high rate of water absorption activities, wetlands should be maintained.

• 한국수산과학회지
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• 제54권2호
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• pp.194-207
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• 2021

It is necessary to assess and manage the different elements of the marine ecosystem, such as climate change, habitat, primary and secondary production, energy flow, food web, potential yield, and fishing, to maintain the health of the ecosystem as well as support sustainable development of fishery. We set up an ecosystem model around the Korean peninsula to produce scientific predictions necessary for the assessment and management of marine ecosystems and presented the usability of the model with scenario experiments. We used the Atlantis ecosystem model based on the marine food web; Atlantis is a three-dimensional end-to-end model that includes the information and processes within an entire system, from an abiotic environment to human activity. We input the ecological and biological parameters, such as growth, mortality, spawning, recruitment, and migration, to the Atlantis model via functional groups using existing research and local measurements. During the simulation period (2018-2019), we confirmed that the model reproduced the observed data reasonably and reflected the actual ecosystem characteristics appropriately. We thus identified the usability of a marine ecosystem model with experiments on different environmental change scenarios.

• 수산해양교육연구
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• 제3권2호
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• pp.73-82
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• 1991

In recent years, the communication and the trade between the Republic of Korea(South Korea) and the Communist bloc has been activated. The simultaneous entrance of South Korea and North Korea to the United Nations will accelerate the political dialogue and also the trade which is indirectly carried out through a third country at present will be turned into direct way. Fisheries products are also treated as one of the important trade goods and there is a hopeful prospect that the amount of trade will be steeply increased in the near future. Furthermore, there is a great possibility of development up to the joint utilization of fishing grounds or the joint investment in fisheries projects. Concerning such points, since it is very much important to understand the present status of fisheries in North Korea, the author made a study on this field as requested by the Board of Unification, and report a part of the study here. The prominent character of North Korea's ruling sea area is that the sea is completely separated into two regions-the East Sea Region and the West Sea Region-and no continuity exists between them. The East Sea Region locates in the fringe of the biggest fishing ground of the world-the North Pacific Ocean-and very rich in resources not only warm water fishes but also cold water fishes. Especially alaska pollack, Theragra chalcogramma, is caught abundantly in this region. Contrary to that, fishing activity in the West Sea Region seems to be interrupted in winter. Even though some valuable warm water fishes-yellow corvenia, Pseudosciaena manchurica, and hair tail, Trichiurus lepturus, and so forth-come to this region from spring to summer along the coast line of this region for spawning, and vigorous fishing activity is carried out. But the most of them migrate southward to the neighboring waters of Cheju Island for wintering from autumn to winter, and so the fishing activity in this region seems to be interrupted greatly during winter. The total number of fishing boats in North Korea is estimated at 36 thousand and the rate of mechnization at about 70% compared with 99 thousand and 78% in South Korea. North Korea proclaimed an exclusive economic zone of 200 nautical miles in 1977. Specific character of this zone is setting of military boundary zone, up to 50 miles from the base line in the East Sea Region and also it covers whole region of the economic zone in the West Sea Region. Especially in the East Sea Region she set up a straight base line which can not be permissible by the international law. North Korea's statistics on fisheries product has not been announced officially on account of her unique isolationism, but it can be estimated through several data procured. At the first, the amount of fisheries products in the North Korea is reported as about 1.7 million ${\frac{M}{T}}$ by Fisheries Statistics which issued by the FAO in 1987, but a North Korea's trade organization announced the amount as 3.5 million ${\frac{M}{T}}$ in 1988. The former seems to be underestimated and the latter must be an exaggeration. According to Chikuni, who is a Japanese worker for FAO, prepared the unofficial statistics based on the evidence which he collected through the fineries development plan of the FAO/UNDP, and estimated the mean amount between 1982 and 1984 was 2.4 million ${\frac{M}{T}}$ or so. The Board of Unification estimated on the basis of various factors that the amount was 2.2 million ${\frac{M}{T}}$ or so in 1987 and in 1988. This seems to be the most reasonable. To solve the chronic lack of foreign currency, North Korea makes effort on the development of fisheries, and has even aimed fisheries product at 11 million ${\frac{M}{T}}$ by 1993, but this target looks unrealistic under the present circumstances. Somehow, we can exploit her extreme policy which has gone so far as to establish such an excessive and impractical target. Nevertheless this will be helpful to promote the joint development of the fishery activity between South Korea and North Korea.