• Fisheries and Aquatic Sciences
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• 제25권12호
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• pp.619-625
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• 2022

The study carried out a 15-day feeding trial of the fleshy shrimp broodstock that have just finished their first spawn using five different maturation feed types (three types of manufactured feed, fresh feed, and commercial feed) to induce multiple spawning in the shrimp and then analyzed and compared hemolymph levels of total protein, total lipid, hemocyanin, glucose, and cholesterol as well as ovary histology between the treatments to identify the potential of the experimental diets to be utilized as maturation feed. The study found that the manufactured diets of polychaetes + clam and polychaetes + clam + squid resulted in significantly higher levels of lipid and protein in shrimp hemolymph suggesting an indicator of multiple spawning in the fleshy shrimp. The other manufactured diet of polychaets + squid led to the highest 2nd spawning with significantly lower levels of lipid, protein, and cholesterol in shrimp hemolymph. The fresh feed treatment showed similar hematological as well as histological responses to the manufactured diet of polychaetes + squid, but with a significantly lower spawning volume compared to the other treatments. The study demonstrated that the manufactured diets could replace fresh feed as maturation feed and attain a higher shrimp maturation than the commercial feed.

• 한국발생생물학회지:발생과생식
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• 제14권1호
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• pp.21-25
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• 2010

Nile tilapia (Oreochromis niloticus) are mouth-brooders so that the females holding eggs in their mouth sacrifice their somatic growth for reproduction. For this reason, artificial control of reproduction for the culture of this species has been of interest. Manipulation of photoperiod is an emerging technique for such purpose, but little information is available to establish appropriate photoperiod regime. To obtain necessary basic information, sexually mature females were individually accommodated to glass aquarium, and the spawning activity of these females were monitored for two years under natural photoperiod regime. Female tilapia spawned most frequently on March, April and May when the day length gradually increased from 11 hours to 14 hours and least frequently on September, October, November and December when the day length gradually decreased from 13 hours to less than 10 hours in the first year. The decrease of spawning frequency as day length decreased was also observed in the second year, although the increase of spawning frequency as day length increased was less clear. Spawning of female tilapia was less active when the night was dark due to the disappearance of moonlight (Dark Phase), compared to the Phase of Getting Lighter, Light Phase and Phase of Getting Darker. Results from this study suggest that long day length, particularly increasing phase, is favoured for active spawning of Nile tilapia, and that this species, as a tropical fish species, may utilize changing lunar phases as a secondary environmental cue for reproduction.

• Ocean and Polar Research
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• 제31권3호
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• pp.257-264
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• 2009

Seventeen females of the mud crab Scylla serrata, from the State of Kosrae, Micronesia, were transported to the Fisheries Resources Research Institute, Gyeongsangnam-do, in oxygen-filled plastic bags. After acclimatization to a $30^{\circ}C$ holding temperature, nine females were selected for seed production trials. Spawning was hastened using eyestalk ablations; however, this may not be required in commercialscale mud crab seed production. Primary spawning produced an average of 2.4 million hatched larvae, whereas secondary spawning produced 0.4 million. About 10 days elapsed between spawning and hatching and 30 days between hatching and crablet. Mass mortalities up to 90% were observed between stages zoea 1 and zoea 2 in every trial. The highest survival rate from zoea 1 to crablet was estimated at 0.25%. Most commercial shrimp hatcheries in Korea are equipped with almost all necessary facilities and could be converted easily to mud crab hatcheries, able to run three to four times per year using hatchery technologies developed for blue crabs and Chinese mitten crabs.

• 한국어류학회지
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• 제28권2호
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• pp.72-78
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• 2016

북방종개 Iksookimia pacifica의 연령 및 산란기 특징을 밝히기 위해 2013년 1월부터 12월까지 강원도 고성군 북천에서 조사를 실시하였다. 전장빈도분포도를 이용하여 연령을 추정한 결과 암컷은 산란기 (7월)를 기준으로 전장 30~49 mm는 만 1년생, 50~74 mm는 만 2년생, 75~99 mm는 만 3년생, 100~124 mm는 만 4년생, 130~160 mm는 만 5년생 이상으로 추정되었다. 성비 (♂/♀)는 0.63이었으며 암컷이 수컷보다 30~60 mm가 더 컸다. 이차 성징인 수컷 가슴지느러미의 골질반은 부화 후 13개월 후에 생성되어 암 수가 구별되었다. 산란기는 생식소성숙도로 추정한 결과 7~8월 (산란성기 7월)로 추정되었으며, 포란수는 $2,503{\pm}1,337$개, 성숙난의 크기는 $1.11{\pm}0.04mm$였다.

• 한국패류학회지
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• 제31권2호
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• pp.113-121
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• 2015

Gametogenesis, mating behaviour and spawning of Octopus ocellatus were investigated by histological study. This species is dioecious, and showed a protandry phenomenon. Ooogenesis (in females) and spermatogenesis (in males) can be classified into 3 stages, respectively. O. ocellatus copulates in one of two ways: a male may leap upon a female, mounting her mantle, or a male may sit near the female and extend the hectocotylized third right arm toward her. Spawning occurred between April and June in females, and between March and May in males of O. ocellatus. The spawning period was once a year and the peak took place between May and June. A number of flatened follicle cells, which were attached to an oocyte, were involved in vitellogenesis in the cytoplasm of the vitellogenic oocyte (maturing oocyte), and formation of chorion membrane (secondary egg membrane) of the ovarian eggs. Fecundity per female closely related to GSI was 294-660 eggs (average, 429 eggs). The diameters of the ovarian eggs surrounded by chorion membrane were approximately in the range of 10.10-2.50 mm. Each ovarian egg laid by a female was connected to an egg string. Each egg string was 1-5.5 cm (average 3.6 cm). The total number of eggs laid by a female of this species ranged 218-314, the egg sizes were independent to the size of female adult. this species has a life mode showing some special reproductive characteristics of an annual semelparity as shown in Octopodidae species because we have never seen a female spawning a second time.

• 한국발생생물학회지:발생과생식
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• 제1권2호
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• pp.181-187
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• 1997

This study has been conducted to investigate the mating behavior, time sequence of mating and time limit with which female can fulfill spawning and brooding after pre-spawning molting in the giant fresh-water prawn, macrobrachium rosenbergii reared in the laboratory. the results obtained were summarized as follows. Mating happened spontaneously as the following sequences: courting gesture, seizure of female by male, mounting, turning of female, copulation. The entire mating lated approximately seven minutes. The endopodite of 2nd pleopod of male bore the appendix masculins whcih are male's secondary sex characteristic. cinciulli was formed at the distal portion of appendix interna which are on the upper portion of appendix masculins and helped stabilizing the connection of each side of 2nd pleopod during mating. After the connection of each side of 2nd plepod was fixed on the posterior portion of the thoracic sternum in female, a gelatinous spermatophore that emitted at the basipodite of 5th pereiopod during courting gesture was deposited on the ventral groove of 2nd, 3rd, 4th and 5th pereiopod. time limit which female can fulfill copulation and brooding was from 3 hours to 15 hours after pre-spawning molting.

• 한국어류학회지
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• 제23권2호
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• pp.158-162
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• 2011

만경강의 삼천에 서식하는 점줄종개 Cobitis lutheri의 성장과 산란생태에 대해 조사하였다. 연령은 산란기인 7월을 기준으로 1년생은 전장 40~60 mm, 2년생은 전장 60~80 mm, 3년생 이상은 80~110 mm로 추정되었다. 성비(수컷/암컷)는 0.78이었고, 암컷이 수컷보다 20~30 mm가 더 컸다. 이차성정 인 골질반(lamina circularis)은 만 1년이 되면서 생성되었으며, 수컷은 성숙 및 산란기인 4월부터 9월까지 반문의 성적이형을 보였다. 산란성기는 수온이 $24{\sim}26^{\circ}C$가 되는7월 초부터 중순까지로 추정되었다. 성숙한 암컷의 포란수는 $1,127{\pm}453$개, 난경은 $1.09{\pm}0.02$ mm였다.

• 한국어류학회지
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• 제18권2호
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• pp.141-147
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• 2006

A. signifer의 성숙한 암수는 외형적으로 형태와 체색이 다르며, Hubbus and Laglar(1964)의 방법에 따라 계측한 11개의 형질 중에서 체장에 대한 두장 및 체고의 백분비, 두장에 대한 문장 및 양안간격의 백분비에서 암수 간에 유의한 차이가 있었다. 혼인색은 전체적으로 녹색계열의 색이 가장 폭넓게 분포하며 몸통부분은 녹색과 푸른색계열, 배 부위에는 노란색계열이 대부분이었고, 미병부는 붉은색계열과 노란색계열이 분포하였다. A. signifer의 추성은 입의 바로 위 양쪽으로 각질 위에 밀집되어 형성되어 있었다. 한쪽에 25~30개 정도의 추성이 있었고, 비산란기인 9월에 추성은 대부분 사라지고 양 끝부분에 일부만이 흔적으로 남아 있었다.

• 한국어류학회지
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• 제28권4호
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• pp.239-248
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• 2016

한국고유종 동방종개 Iksookimia yongdokensis의 생태적 특성을 밝히기 위해 2015년 3월부터 2016년 2월까지 경상북도 영덕군 축산군의 축산천에서 서식지와 연령, 산란기 특성 등을 조사하였다. 연령별로 서식지를 분석한 결과 당년생(0+)과 1~4년생은 구별되었는데, 당년생은 유속이 느리고 ($2.4{\pm}2.09\;cm/sec$) 수심이 낮으며 ($29.2{\pm}7.57\;cm$) 모래 바닥 (하상 크기 $0.6{\pm}1.44\;cm$)에 주로 서식하였지만, 1~4년생은 유속이 비교적 빠르고 (3.8~4.6 cm/sec) 수심은 깊은 (50~70 cm) 자갈과 돌 바닥(하상크기 5.5~6.1 cm)에 주로 서식하여 차이를 보였다. 전장빈도분포도로 연령(암컷)을 추정한 결과, 산란기인 6월에 35~64 mm는 만 1년생, 65~94 mm는 만 2년생, 95~119 mm는 만 3년생, 120~145 mm은 만 4년생 이상으로 추정되었다. 생후 13개월 후에 수컷 가슴지느러미 기조에 골질반(lamina circularis)이 형성되어 암 수가 구별되었고, 성비(♂/♀)는 0.69였으며, 암컷이 수컷보다 10~30 mm가 더 컸다. 산란기는 생식소성숙도 (GSI)로 추정한 결과 6~7월 (수온 $20{\sim}25^{\circ}C$)이었고, 포란수는 $2,292{\pm}618$개, 성숙난 크기는 $1.46{\pm}0.02\;mm$였다.

• 한국수산과학회지
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• 제42권1호
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• pp.48-55
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• 2009

The gonad maturation and spawning of blue crab, Portunus trituberculatus (Miers, 1876) using samples caught by trammer net in the western coast of Korea from January to December. The gonadosomatic index (GSI) showed the highest value of 15.0 in June and lowest value of 1.29 in August. Hepatosomatic index (HSI) showed the lowest in the spawning season from June to July. Thereafter, from August the value started to increase to 5.77 in December, showing an adverse trend against GSI. In the histological studies of the female reproductive organ, the gonad filled with primary oocytes from January to February and secondary oocytes in May. The female gonads mature from June, and mature and immature groups could be distinguished from December to February or March. In August, female developed another cycle of gonad development, showing new primary oocytes in the gonads again. Some of female crabs had receptaculum filled with already active sperm cells in it from March to May. In the time of August to September, almost all the females had the sperm sacs in the receptaculum. From the result, the coupling period estimated from August to September. Total RNA and DNA values of the crabs were highest in May (2.51, $0.57{\mu}g/mg$). The DNA value remained unchanged except for the value in May ($0.09-0.13{\mu}g/mg$). while RNA value was lowest in January ($1.08{\mu}g/mg$). The RAN/DNA ratio was the lowest (6.23%) in May and highest (18.05%) in July. The value of correlations coefficient between body weight and fecundity of the crabs was higher that of between carapace width and fecundity.