• The Korean Journal of Malacology
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• v.19 no.2
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• pp.117-124
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• 2003

Reproductive cycle and sex ratio of the marsh clam Corbicula japonica, a oviparous clam, were investigated monthly by histological observation. Samples were collected in brackish water of Namdae stream on the east coast of Korea from November 2000 to October 2001. It was able to devide the reproductive cycle of this species into five successive stages; early active (April to June), late active (May to June), ripe (June to August), partially spawned (June to September), spent (September to January) and resting stage (February to April). The spawning period was from July to September, and the main spawning occurred between August and September when seawater temperatures reached above 26$^{\circ}C$. Mature eggs of Corbicula japonica were 60-70 ${\mu}m$ in diameter. The sex ratio of individuals over 10.1 mm in shell length was about 1:1 (x$^2$ = 1.22, p > 0.05).

• Korean Journal of Fisheries and Aquatic Sciences
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• v.20 no.6
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• pp.489-500
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• 1987

Annual reproductive cycle of Bluegill, Lepomis macrochirus (RAFINESQUE) were studied in the natural population. Based on these informations, reproductive mechanism of the fish including activation, degeneration and remature were examined under the controlled conditions of temperature and photoperioe. In the natural populations, gonads began to grow with the temperature increase in March ana matured in June, and spawning occurred in July. With the onset of the shorter day-length and the maximum temperature condition in August, the gonads began to degenerate. Resting stage was continued during winter season. In the laboratory-reared population, activation of the gonads was initiated by the complex environmental factors including higher temperature$(>15^{\circ}C)$ and longer photoperiod $(>14L)$. For the maturation, photoperiod of more than 14 hours was critical. Under this condition higher temperature was the only compensative factor. Regeneration of the gonads was induced by higher temperature$(>25^{\circ}C)$ and the shorter photoperiod accelerated the regenerative processes. Even from the resting stage the gonads can be induced to matured stage by the longer photoperiod $(>15L)$. Based on these observations, the reproductive rhythm of this fish is supposed to be artificially controlled.

• Journal of Veterinary Clinics
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• v.26 no.6
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• pp.647-649
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• 2009

An orchiopexy was performed in an 18-month old adult English bulldog with bilateral cryptorchidism. One month postoperatively, the dog was twice-treated with GnRH (50 ug/kg) at an interval of 2 weeks. Semen was collected and evaluated before and after surgery. Fertility was determined by artificial insemination. No spermatozoa were observed before orchiopexy and 2 months postoperatively. However, 6 live sperm were detected 4 months postoperatively and normal sperm characteristics (except sperm concentration) were present 7 months postoperatively. A female bulldog, inseminated with the semen from the bulldog 8 months postoperatively, delivered 6 offsprings. Spermatogenesis and spermatozoa with fertilizing capacity were recovered by postpubertal orchiopexy and GnRH therapy in a bilateral cryptorchid dog.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.17 no.6
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• pp.523-528
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• 1984

The small filefish, Rudarius ercodes, generally spawning from mid May to early October in the natural habitat, was exposed to various photoperiod and temperature regimes. These environmental effects on the gonad activity, regression and recrudescence were experimentally investigated based on the mechanism of reproductive cycle. Spawning season was initiated in the early spring with the gonad activated by long photoperiod(13L) and stimulated by compensatory temperature rising. Even when the gonad activated readily at the above critical daylength (12L to 13L)was kept back at the below if, it went on maturing. At the end of spawning period (mid September), since the shortening of daylength (12L) resulted in the gonad regression regardless of temperature, the short daylength might be related to the termination of spawning in situ. When the regressive gonad at the post spawning period was treated by the above 13L: $20^{\circ}C$ condition, it could recrudesce and bring forth even spawning. From this fact, the feasible control of annual reproductive cycle of small filefish was recognized. But even in the long daylength, the temperature above $28^{\circ}C$ was preventive of gonad maturation.

• 대한생식의학회:학술대회논문집
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• 2006.11a
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• pp.158-159
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• 2006

• Proceedings of the Korean Society of Fisheries Technology Conference
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• 2001.05a
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• pp.367-368
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• 2001

고막류에는 피조개(Scapharca broughtonii)를 비롯하여 고막(S. granosa bisenensis), 새고막(S. subcrenata), 큰이랑피조개 S. satowi(Dunker)가 있다. 큰이랑피조개의 생산량은 전량 자연산에 의존하고 있으며, 최근 들어 자원이 감소하는 추세에 있어 양식 개발품종으로 기대되는 종이다. 피조개의 인공종묘생산은 대야(1962)에 의해 시작되어 중촌ㆍ암본(1975)에 의해 기술이 확립되었으며 우리나라에서는 종묘생산 및 유생사육에 관한 연구결과들이 보고되어 있으나, 큰이랑피조개에 대하여 생식ㆍ생리에 대한 연구는 거의 이루어지지 않고 있다. (중략)

• Clinical and Experimental Reproductive Medicine
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• v.37 no.2
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• pp.169-172
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• 2010

Retrograde ejaculation is a condition that causes male infertility. Infertiltiy treatment is usually based on assisted reproductive technology with the use of sperms recovered from the bladder after ejaculation. Many pregnancies have been tried by artificial intrauterine insemination with the husband's sperm recovered from voided urine. In this case, ovulation was induced by clomiphene citrate and human menopausal gonadotropin, pH and osmorality of urine was controlled by modified Ham's F-10 contained 10% serum substitute supplement and immediately semen collection, to improve sperm motility. We had experienced a successful pregnancy case by above method, and reported with brief review of literature as well.

• Clinical and Experimental Reproductive Medicine
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• v.3 no.2
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• pp.29-34
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• 1976

The changes of the plasma progestin concentations in normal pregnancy and artificially maintained pregnancy of the rabbits by hormonal replace therapy after induced ovulation and insemination on Day 1, followed by ovariectomy on Day 2, were checked by direct measurement, competitive protein-binding assay, from the time of mating through to parturition. The results obstained in this experiment can be summarized as follows: (i) The mean concentration of progestin in normally pregnant rabbits increased from $1.7{\sim}2.7$ ng/ml on Day 1 to $19.8{\sim}25.3$ ng/ml on Days $13{\sim}15$ and declined slowly thereafter until term. (ii) The progesterone levels in artificially maintained pregnancy by hormonal replacement therapy showed quite a similar pattern to that in normally pregnant rabbits.

• Proceedings of the Korean Society of Crop Science Conference
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• 2000.04a
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• pp.120-121
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• 2000

• Proceedings of the Korean Society of Fisheries Technology Conference
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• 2002.10a
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• pp.47-48
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• 2002

바다 속에서의 소음은 해풍, 파랑, 강우 등 자연소음과 어류의 생식음, 신호음, 식이음 등 생물이 내는 음과 선박의 엔진 등과 같은 인공음이 있는데 수중가청음을 이용한 어군의 유집은 어장 조업 시에는 조업 능률을 향상시키고, 축양 어업에서는 음향 제어에 의한 자동급이와 치자어의 육성단계에서부터 음향순치를 통해 어류를 일정한 해역에 정착, 서식하도록 할 수 있어 해양목장화 등 여러 면에 응용이 되어지고 있다. (중략)