• 생명과학회지
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• 제27권10호
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• pp.1097-1103
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• 2017

뱀장어(Anguilla japonica)의 인공종묘생산은 연어뇌하수체추출물(SPE, salmon pituitary extract)을 암컷 뱀장어에게 지속적인 투여를 하고 인위적으로 성성숙을 유도로 얻은 난과 정자를 인공수정을 하고 부화 시켜 생산한다. 하지만 SPE를 반복적으로 복강에 주사하는 방법은 암컷 뱀장어에게 많은 스트레스를 주며, 결국 스트레스로 인하여 완전한 성성숙을 하지 못하고 폐사에 이르게 되거나 배란한 난의 질이 좋지 않아 부화율과 자어의 생존율이 떨어지는 문제점을 갖고 있다. 본 연구에서는 뱀장어의 성성숙 유도에 유효하다고 알려진 호르몬이 주입된 osmotic pump를 복강에 삽입 후 암컷 뱀장어의 성성숙 유도를 하였다. 본 연구결과 SPE를 투여한 실험어의 GSI가 hCG, GnRHa, MT를 각각 또는 함께 투여한 실험구 보다 유의하게 증가하였으며 조직학적 분석결과에서도 난소의 난모세포가 핵이동기 단계로 발달되었음을 관찰할 수 있었다. 본 결과를 통해 osmotic pump를 이용한 암컷 뱀장어 인위적 성성숙 유도 방법으로 이용 가능할 것으로 생각된다.

• 한국수산과학회지
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• 제50권6호
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• pp.770-776
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• 2017

This study investigated the effects of recombinant eel gonadotropin hormone (rJeGTH) produced in silkworms, with and without a carboxyl-terminal peptide from equine chorionic gonadotropin (eCG), on the induction of sexual maturation in female eels Anguilla japonica. Experiments were conducted both in vivo and in vitro. In in vitro trials, germinal vesicle breakdown (GVBD) induction did not significantly differ between rJeFSH and $rJeFSH{\cdot}eCG$ treatments and the control group. However, previous studies did find that rJeLH and $rJeLH{\cdot}eCG$ treatments induced GVBD in female eels. Our in vitro exploration of $estradiol-17{\beta}$ ($E_2$) levels in immature ovarian tissues revealed significantly higher $E_2$ levels in the group treated with $rJeFSH{\cdot}eCG$ $1{\mu}g/mL$ than in the control group. In contrast, the in vivo experiments showed no effect of recombinant hormones on the sexual maturation of feminized eels. Previous studies and our own in vitro results have clearly shown that rJeGTH and $rJeGTH{\cdot}eCG$ have a positive effect on the sexual maturation of feminized eels. To develop the activity of rJeGTH in vivo, further studies should confirm circulation time and activity of these hormones in eels' bloodstream, modify the structure of the recombinant gene, and implement additional glycosylation.

• 한국패류학회지
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• 제27권2호
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• pp.143-148
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• 2011

연구는 양질의 피조개 수정란 확보와 안정적 종묘생산을 위하여 피조개 모패의 먹이생물로 미세조류 3종 (Isochrysis galbana, Tetraselmis tetrathele, Phaeodactylum tricornutum) 을 단독 또는 혼합 공급하여 먹이생물에 따른 피조개 모패의 비만도, 생식소발달, 성숙유도율 및 생존율을 조사하였다. 사육 45일 경과 후 피조개 모패의 완숙기 출현율, 성숙유도율 및 생존율은 3종의 미세조류를 혼합 공급하거나 T. tetrathele를 단독공급한 실험구에서 가장 높았다.

• 한국패류학회지
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• 제25권2호
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• pp.113-119
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• 2009

본 연구는 2008년 3월 24일에 전남 영광군에서 채취한 말백합 어미 1,200 마리를 확보하여 수온조절 (20, 25, $30^{\circ}C$ 및 자연해수) 에 의한 인위적인 성 성숙을 유도하였으며, 성숙 유도된 어미로부터 생존율, 비만도, 생식소 및 성숙 소요일수를 조사하였다. 말백합 어미의 연체부지수는 사육초기에는 다소 낮아지는 경향이 있었으나, 5월 중순부터 증가하는 경향이 있었으며, 시험 종료 시에는 연체부 지수가 급격히 증가하였으며, 각부용적지수도 유사한 경향을 나타내었다. 말백합의 생식소 발달단계는 비활성기, 초기 활성기, 후기활성기, 완숙기, 방출 및 퇴화기의 5 단계로 구분할 수 있는데, 시험 개시일인 3월 25일경은 전기 활성기였으며, 시험 종료일인 6월 30일에는 수온별로 다양한 생식주기를 나타내었다. 시험 종료 시 성숙 유도율은 $30^{\circ}C$ 실험구에서 46.0%로 가장 높았고, $15^{\circ}C$ 실험구 35.0%, 자연수온 18.0% 및 $20^{\circ}C$ 실험구 12.0%로 순으로 나타났으며, 시험 기간 중 생존율은 전 구간이 90% 이상으로 나타났다. 사육수온을 20, 25, $30^{\circ}C$ 및 자연수온으로 성숙 시험한 결과, 암컷의 경우 $30^{\circ}C$ 실험구가 성숙이 가장 빨랐고, 수온이 낮을수록 늦은 경향이었으며, 수컷도 비슷한 경향을 나타내었다. 말백합의 수온별 어미성숙은 $20^{\circ}C$ 보다는 수온이 높은 실험구인 25, $30^{\circ}C$에서 성숙 유도율이 높게 나타났다.

• 한국패류학회지
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• 제20권1호
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• pp.75-84
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• 2004

Reproductive cycle, the condition index, sex ratio of the Pacific oysters, Crassostrea gigas were investigated by histological and morphometric data. The specimens were collected in the two oyster farms of Geoje and Namhae, Gyeongsangnam-do, Korea, from November 1995 to October 1996. Growth of shell length in two regions was similar, but growth of total weight of the oyster in Namhae was faster than that in Geoje oyster farm. The spawning periods in female and male clams were from July to October in Geoje and from June to October in Namhae oyster farm. Ripe oocytes were approximately 50 m in diameter. The reproductive cycle of in females and males in Geoje and Namhae oyster farms can be divided into five successive stages: early developing, late developing, ripe, partially spawned and spent/inactive. Monthly changes in gonad developmental phases showed somewhat different patterns between female and male clams except for the spawning period. On the whole, however, monthly changes in the gonad developmental phases showed a similar pattern in the same sex. The sex ratios of females to males in Geoje and Namhae oyster farms were not significantly different from a 1:1 sex ratio ($x^2$ = 0.55 (p > 0.05) in Geoje and $x^2$ = 0.27 ( p > 0.05) in Namhae). Artificial induction of maturation by heating of adult oysters (two-year-old) was investigated from 17 January to 18 March in 1996. Maturity at the fixed water temperature group of $20^{\circ}C$ was 80%, it showed the highest maturity of experimental groups cultured for five weeks. The survival (%) of Crassostrea gigas in the raised water temperature experimental groups (15, 20, $25^{\circ}C$) were over 98.5%, as similar to the control group (100%). But, the survival of C. gigas in the fixed water temperature experimental groups (15, 20, 25, $30^{\circ}C$) were decreased with the increase of the water temperatures. In the fixed water temperature experimental group of $30^{\circ}C$, the survival was 51.1%. Base on these results, the fixed water temperature of $20^{\circ}C$ was the best condition for artificial induction of sexual maturation.

• 한국패류학회지
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• 제22권2호
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• pp.175-182
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• 2006

본 연구는 2004년 3월 10일 남해 강진 만에서 채취한 피조개 어미 1,200 마리를 확보하여 수온조절에 의한 인위적인 성성숙을 유도하였으며, 성숙 유도된 어미로부터 잔존율, 비만도, 생식소 조직검사, 적산수온 및 성숙소요일수를 조사하였다. 성 성숙유도된 어미의 잔존율은 $20^{\circ}C$가 94.8％로 가장 높았고, $23^{\circ}C$가 90.3％, 대조구(자연수온구)가 84.8％이었고, $26^{\circ}C$가 18.1％로 온도가 높을수록 잔존율이 낮은 경향이 있었다. 42일 째 생식소 조직의 암컷의 완숙기 출현율은 $23^{\circ}C$ 실험 구에서 67%로 가장 높았고, $20^{\circ}C$ 실험구에서 56%, $26^{\circ}C$에서 22%였으며, 자연수온 실험구에서는 성숙이 매우 늦어 완숙기에 이르지 못하였다. 수컷의 경우, $23^{\circ}C$ 실험구에서 완숙기 출현율이 100%로 가장 높았고, $20^{\circ}C$ 실험구에서 87%, $26^{\circ}C$에서 73%였으며, 자연수온 실험구에서는 50% 순으로 나타났다. 성숙소요일수는 $23^{\circ}C$와 $20^{\circ}C$에서 각각 42일 및 49일, 대조구인 자연수온 $(9.5-14.8^{\circ}C)$에서는 79일이였으며, 성 성숙 유도율은 $20^{\circ}C$와 $23^{\circ}C$에서 각각 55.5% 및 60.5%로 타 실험구와는 유의한 차이를 나타내었다 (p < 0.05). 따라서 $20^{\circ}C$ 실험구 (적산수온: $1,295^{\circ}C$) 가 피조개 어미를 인위적으로 성 성숙을 유도하는데 가장 좋은 것으로 판단된다.

• Fisheries and Aquatic Sciences
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• 제21권11호
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• pp.34.1-34.13
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• 2018

Sexual maturity ($L_{50}$), the length at which 50% of fish in a size class are mature, is a key aspect of domestication of new fish species because it guides the procedure for identification of appropriate broodstock size for artificial spawning. In this study, the $L_{50}$ was determined for 1083 Barbus altianalis samples obtained from Lake Edward and the Upper Victoria Nile. Gonads of freshly killed samples were examined macroscopically and verified with standard histological procedures for the maturation stages that were used to determine $L_{50}$. Oocytes and spermatogenic cell sizes were compared for fish obtained from both water bodies. Results indicated that there were no variations in macro gonad features observed for fish from Lake Edward and Upper Victoria Nile. Similarly, there were no significant differences in oocyte sizes (P > 0.05) between the two populations but significant differences in spermatogenic cell sizes were noted (P < 0.05) except for spermatozoa (P > 0.05). This however did not suggest peculiar differences between the two populations for staging the gonads. Consequently, no staging variations were suggested for both populations in determination of $L_{50}$. Sexual maturity was found in the same class size of fork length (FL) 20-24.9 cm and 35-39.9 cm for males and females from both water bodies, respectively. At this FL, however, males were too small, and for good selection of vigor broodstocks for spawning and conservation purposes, they are better picked from class size of 30-34.9 cm FL and above. These findings were crucial for integration of appropriate breeding size in spawning protocol by farmers and fisheries scientists conserving wild B. altianalis populations.

• 한국가축번식학회지
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• 제11권3호
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• pp.170-180
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• 1987

This study was undertaken to determine the effects of HCG and trout pitutary on sexual maturation and ovulation in the Korean loach, Misgurnus anguillicaudatus. Sexual maturation was observed in the fish treated with 250＋125 IU HCG within 2-4 days following injections. Total ovary weight and GSI were significantly greater in the hormone-treated fish than in the control fish. Furthermore, in the hormone-treated fish body weight increased by about 4-9 percent in 2 days. The water content of the ovulated eggs of the fish treated with 250＋125 IU HCG was also greater than that in the control. Changes in both macroscopic & microscopic appearnce of Korean loach ovaries are describled, as well as changes in the gonadosomatic index. Oocytes pass through seven cytologically changes in the relative stages. By examining these stages, it was found that oogenesis occures in two broad phases. The previtellogenic phasebegins as a new oogonia continues to arise following spawning. These rapidly develop into early perinucleolus oocytes, which in turn develop into resting stage oocytes. Most oocytes remain in this stage when they develop into late perinucleolus oocytes. The vitellogenic phase begins as these late perinucleolus oocytes become transformed into early maturing oocytes through the accumulation of yolk. The cytoplasm completely fills with yolk as oocytes reach the late maturing stage. Shortly before spawning the final hyaline stage of developing is reached. Changes in the microscopic appearances of the ovaries were well correlated with changes in both gonadosomatic index and macroscopic appearance.

• 한국발생생물학회지:발생과생식
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• 제20권2호
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• pp.119-125
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• 2016

This study describes results on sexual maturation and characteristics of natural spawned eggs to develop a method for the production of stable, healthy fertilized eggs from captive-reared yellowtail kingfish, Seriola lalandi. A total of 59 yellowtail kingfish were captured off the coast of Jeju Island, after which the broodstock was cultured in indoor culture tank ($100m^3$) until they were 6.1-14.9 kg in body weight. As part of the rearing management for induced sex maturation, the intensity of illumination was maintained at 130 lux. The photoperiod (light/dark; L/D) was set to a 12 L/12 D from October 2013 to January 2014, and 15 L/9 D from February 2014 to June 2014. Feeds comprised mainly EP (Extruded Pellets), with squid cuttlefish added for improvement of egg quality, and was given from April to June 2014. The first spawning of yellowtail kingfish occurred in May 3, 2014, at a water temperature of $17.0^{\circ}C$. Spawning continued until June 12, 2014, with the water temperature set at $20.5^{\circ}C$. Time of spawning was 26 times at this period. The total number of eggs that spawned during the spawning period was $4,449{\times}10^3$. The buoyant rate of spawning eggs and fertilization rate of buoyant eggs during the spawned period were 76.1% and 100%, respectively. The diameters of the egg and oil globule were $1.388{\pm}0.041mm$ and $0.378{\pm}0.029mm$, respectively, which was higher in early eggs than in those from late during the spawned period.

• 한국어류학회지
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• 제12권1호
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• pp.46-53
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• 2000

돌돔 Oplegnathus fasciatus의 인위적인 성 성숙 및 산란 유도를 위한 연구에서, 3년생 돌돔 친어를 대상으로 수온 및 광주기 조절에 의한 생식소 발달을 조직학적으로 조사하였다. 수온 및 광주기 조절구 (Exp. I)는 1996년 12월부터 1997년 2월까지 수온은 $14.5^{\circ}C$에서 $21.0^{\circ}C$ 그리고 광주기는 10 : 30 L에서 15 : 30 L로 증가시킨 후 4월까지 계속 유지시켰다. 수온 조절구 (Exp. II)에서 수온은 Exp. I과 동일하게 조절하였고, 광주기는 3월 초순까지는 자연 광주기로 조절하였다가 이후 장일 광주기 (15 : 30L)로 재조절 하였다. 대조구는 1996년 12월부터 1997년 4월까지 해상 가두리의 자연 조건하에서 사육하였다. 생식소 활성은 1 월부터 Exp. I, II 모두에서 시작되었다. 그리고 성숙과 산란은 Exp. I에서는 수온과 광 주기가 각각 $21.0^{\circ}C$와 15 : 30L까지 도달한 2월부터 시작되었으나, Exp. II는 3월 초순까지도 부분적 성숙만 유도되다 장일 광주기 (15 : 30 L)로 조절한 후 3월 하순 부터는 성숙과 산란이 시작되었다.