본 연구는 붉바리 어미의 사육환경에 따른 난질의 변화를 난의 생화학적 분석을 통하여 난질 에 영향을 미칠 수 있는 요소를 구명하기 위하여 수행하였다. 그 결과 육상수조에서 사육하는 것보다 해상가두리에서 사육할 때 부상률, 수정률, 난 발생 생존율 및 부화율이 우수하였다. 그 리고 해상가두리에서 생산한 수정란의 유리아미노산의 함량이 높았다. 즉, 해상가두리에서 사 육관리할 때 난질이 우수한 수정란을 생산할 수 있고, 난질이 우수할수록 유리아미노산의 함 량이 높았다.

The present study was to investigate the source of contamination during semen processing for in vitro uses. In the present study, frozen semen was prepared from liquid semen in our laboratory for in vitro fertilization (IVF) experiments due to lack of fresh semen. Antibiotics were added in the frozen semen extender (kanamycin and gentamicin) and in vitro culture (IVC) medium (gentamicin) for further inhibiting growth of microorganisms. Nevertheless, proliferations of microorganisms were observed in IVC culture drop during culturing of IVF embryos using frozen semen. Randomly 3 samples were taken from the liquid semen, frozen semen and egg yolk. Contaminated IVC medium, frozen-thawed semen, liquid semen and egg yolk were cultured in de Man, Rogosa and Sharpe (MRS) agar medium. Whitish colonies were detected in contaminated IVC drop, frozen-thawed semen samples and egg yolk but no colonies were formed in liquid semen samples. Gram-negative and rod-shaped identical bacteria were found in both frozen-thawed semen sample and contaminated IVC drop and egg yolk samples. Enterobacter cloacae were confirmed by API 20E kit according to manufacturer's instruction with identification value (% ID) 94.3% and T index 0.88. Antibiotic susceptibility tests were done according to Clinical and Laboratory Standards Institute (CLSI) by using ampicillin, amikacin, cephalothin, gentamicin, kanamycin, tetracycline, oxytetracycline, sulfamethoxazole trimethoprim, norfloxacin and ciprofloxacin test. Among them Enterobacter cloacae were resistant to ampicillin, amikacin, cephalothin, gentamicin, kanamycin but susceptible to tetracycline, oxytetracycline, sulfamethoxazole trimethoprim, norfloxacin and ciprofloxacin. From these findings it could be suggested that this contamination sources might be from egg yolk.

나노입자란 직경 100nm 이하의 크기를 가진 입자로 가전, 기능성 화장품, 반도체, 항균제 및 광촉매제 등에 널리 사용되어 있어 본 연구는 9종류의 나노입자가 참굴 수정란에 미치는 영향을 살펴보았다. 나인입자를 첨가하지 않은 대조구에서는 인공 수정한 참굴 수정란의 78%가 D형 유생으로 발생하였다. 은(Ag)이 2% 함유된 AGZ020, Nano silver 및 P-25의 나노입자와 주석산화물인 SnO의 나노입자는 24시간 경과 후 0.05ppm 농도에서 각 각 22%, 52%, 58% 및 76%가 D형 유생으로 발생하였으나, 20ppm 농도에서 8시간 이내 참굴 수정란을 모두 파괴하였다. In, Sb, Sn, Zn 및 Ag-TiO2의 나노입자는 24시간 경과 후 0.05ppm 농도에서 모두 70%이상의 D형 유생으로 발생하여 상대적으로 낮은 농도에서 큰 영향을 받지 않는 것으로 나타났으나, 20ppm 농도에서 대조에 비해 D형 유생 발생율이 각 각 57%, 60%, 50%, 65% 및 64%로 저해되었다.

As a preliminary investigation into the effect of environmental factors control for gonadal development, we examined the involvement of photoperiod and water temperature in ovarian development of Epinephelus. akaara. For the induction of sexual maturation, E. akaara reared in recirculating aquaculture system (RAS). During November 2013, the photoperiod and water temperature was adjusted to 12L:12D and 18℃, respectively. In the photo-thermal treatment group, every 3 weeks daylight was increased as follows a 13L:11D and 14L:10D, and control group was maintained under natural condition. After 9 weeks, water temperature was increased 23℃ in photo-thermal treatment group. The sampled fish every 3 weeks revealed increase in gonadosomatic index (GSI; 5.18±1.38), oocyte diameter and vitellogenic oocytes (423.9±36.1 ㎛) were observed in gonads 12 weeks under photo-thermal treatment group. However, ovarian development was maintained immature stage in control group. In this environmental factors manipulation trial, seventy one of the 95 females (578.4 ± 25.4 g in mean body weight, 31.0 ± 0.5 cm mean total length) treated with HCG injection (doses 500 IU/kg BW) were induced ovulation by artificial stripping. The total volume of ovulated eggs were 3,470 ml and the total volume of fertilized eggs was 3,295 ml. The fertilization rate and hatching rate were 95% and 98%, respectively. These results suggest that the photoperiod as well as water temperature are major environmental factors in triggering the gonadal development of E. akaara.

The fertilized eggs of E. septemfasciatus are spherical and transparent with buoyancy at 790 to 890 μm (average 821.8±2.0 μm) in diameter with 170 to 230 μm oil globules (average 192.9±0.93 μm). Hatching began approximately 46 and 35 hours after fertilization at 22.0℃ and 25.0℃ water temperature, respectively. The average total length of newly hatched larvae was 1.75±0.03 mm. Most of the yolk and oil globules were absorbed within 3 to 4 days after hatching. The larvae reached 2.48 to 2.72 mm in total length, and their mouths and anuses opened at 3 to 4 days after hatching. In this time, the mouth diameters of the larvae were 0.209 to 0.238 mm. The larvae reached 3.24 to 4.15 mm in total length at 11 to 17 days after hatching, and began to metamorphose at the time the second dorsal and pelvic spines appeared and elongated. The abdominal cavity was densely lined with melanophores. The larvae reached 5.12 mm in total length at 24 days after hatching.

Various mutants of specialty rice were derived from Ilpumbyeo, a high-quality japonica rice cultivar, through muta-tion breeding by MNU treatment on fertilized egg cells of rice spikelets. The selected mutants revealed glutinous, semi-glutinousfthem were