• 한국수산과학회지
• /
• 제56권5호
• /
• pp.676-683
• /
• 2023

The development of the egg, larvae, and juveniles of Acheilognathus macropterus from the Wicheon stream of Nakdonggang River was investigated for early life history characteristics. The fish used in the study were collected from Wicheon stream located in Bian-myeon, Uiseong-gun, Gyeongsangbuk-do. The fertilized egg was 1.88±0.09 mm (n=30) in long diameter and 1.34±0.06 mm (n=30) in short diameter. After fertilization at a water temperature of 20℃, the egg took 31 h and 40 min to hatch. Newly hatched larvae had an average total length of 3.92±0.13 mm (n=30) and possessed a yolk sac the mouth and anus were not developed. Twenty days after hatching, the postflexion larvae had an average total length of 8.08±0.29 mm (n=30), with the tail tip fully bent at 45° and began feeding. Thirty-three days after hatching, the number of fin stems reached an integer with an average total length of 15.0±1.08 mm (n=30). In this study, differences in the egg size, hatching time, melanophore development period, and distribution location were confirmed between A. macropterus and allied species.

• 한국축산식품학회지
• /
• 제38권3호
• /
• pp.487-497
• /
• 2018

Controlling of microorganisms in the industrial process is important for production and distribution of hatching and table eggs. In the previous study, we reported that chlorine dioxide ($ClO_2$) gas of a proper concentration and humidity can significantly reduce the load of Salmonella spp. on eggshells. In this study, we compared microbial reduction efficacy on egg's surface using hatching eggs and table eggs, internal quality of table eggs, and hatchability after both the conventional method (washing and UV expose, fumigation with formalin) and $ClO_2$ gas disinfection. Application of 40 ppm $ClO_2$ gas to the table and hatching eggs, respectively, reduced the aerobic plate count (APC) with no statistical difference compared with the conventional methods. Additionally, we didn't observed that any significant difference in albumin height, Haugh unit (HU), and yolk color, this result confirms that 40 ppm $ClO_2$ had no effect on the internal quality of the table eggs, when comparing with the UV treatment method. The hatchability of hatching eggs was not statistical different between formaldehyde fumigation and 80 ppm $ClO_2$ gas treatment, though the value was decreased at high concentration of 160 ppm $ClO_2$ gas. From these results, we recommend that $ClO_2$ gas can be used as a safe disinfectant to effectively control egg surface microorganisms without affecting egg quality.

• 농약과학회지
• /
• 제12권2호
• /
• pp.155-161
• /
• 2008

수단과 우리나라에서 수집된 12 가지 식물체 추출물(메탄올 추출 9종, 헥산추출 3종)을 이용하여 실내에서 뿌리혹선충(Meloidogyne incognita)의 부화에 미치는 영향을 조사하였다. 10,000 ppm, 1,000 ppm, 100 ppm 농도의 식물체 추출물에 뿌리혹선충 알을 넣고, 3일과 7일, 21일 후 부화 된 알의 수를 조사하였다 모든 식물체 추출물 처리에서 무처리에 비해 뿌리혹선충 난의 부화억제 활성이 있었다. 농도가 높을수록 부화억제 활성이 높았는데, 10,000 ppm 농도에서는 Quisqalis indica 처리를 제외하고 소수의 개체만이 부화하였다 그리고 Q. indica 처리에서만 7일과 21일째 84.4%와 54.4%가 부화하였고, 대부분의 처리에서는 7일째 이후에 부화되는 알이 없었다. 1,000 ppm농도에서는 10,000 ppm 농도에 비해 부화율이 높았는데, Cucumis mello var agrestis 처리에서 부화율이 가장 낮아 3, 7, 21일 후에 각각 2%와 8%, 3% 만이 부화하였다. 100 ppm 처리에서는 Desmodium caudatum 처리에서 처리 3일과 7일째 부화되는 알의 수가 가장 적었다.

• 한국양식학회지
• /
• 제10권3호
• /
• pp.357-362
• /
• 1997

참가자미의 종묘생산을 위한 생물학적 기초자료를 얻기 위하여 난발생에 미치는 수온과 염분의 영향을 조사하였다. 수정란의 정상적인 부화는 9-$15^\circC$에서 가능하였으며 생존율은 $12^\circC$에서 가장 높게 나타났다. 난발생의 각 단계에 이르기까지의 수온 (T : \circC$)에 따른 발생속도 (t : hour)는 수온이 높을수록 빨랐으며, 그 관계식은 다음과 같았다. 8세포기 1/t=0.0284T-0.0554 (r=0.9999) 상실기 : 1/t=0.0137T-0.0527 (r=0.9998) Kupffer씨포 출현기 : 1/t=0.0035T-0.0133 (r=0.9762) 부화자어기 : 1/t=0.0012T-0.0007 (r=0.9981) 참가자미의 난발생이 개시되는 생물학적 영도는 평균 $2.6^\circC$로 나타났다. 설정 수온별로 수정에서 부화에 이르기까지의 평균 소요시간은 $9^\circC$에서 95.5시간, 12$12^\circC$에서 72.5시간 및 $15^\circC$에서 56.0시간이었다. 염분별 부화까지의 생존율은 35-$38\textperthousand$에서 높게 나타났다.

• 대한수의학회지
• /
• 제33권2호
• /
• pp.277-283
• /
• 1993

In the present study, observations were made on the life-history of Lymnaea viridis under laboratory conditions, involving incubation period of the eggs and their hatching rate, shell length of the newly hatched snails, sexual maturity, size of the snails when the snail produced the first egg-mass, the number of eggs in each egg-mass, egg-laying, ovipostion, growth rate of the snails, and longevity of the snail. At temperatures between $19.8^{\circ}C$ to $22.5^{\circ}C$, incubation period of the eggs occupied 10~12 days, and after beginning of hatching, all young snails emerged completely from the egg-mass within 5 days. The hatching rate was 88%. The average shell length of the newly hatched snails was about 0.064cm. The rate of growth was extraordinarily rapid under good laboratory conditions. When two snails were reared in one culture vessel($20{\times}15{\times}5cm$) with blue-green algae at about $22^{\circ}C$, snail growth was optimal, taking 37 days to reach 1.2cm in shell length. Sexual maturity reached in about 19 days. The size of the snails at sexual maturity was $0.78{\pm}0.05cm$ in length and $0.47{\pm}0.04cm$ in width. The first egg-masses produced were $0.59{\pm}0.22cm$ in length and $0.34{\pm}0.08cm$ in width, and contained 7~38 eggs. The eggs are usually laid in water. The egg-laying was affected by food and temperature. Snails fed with blue-green algae at about $22^{\circ}C$ produced larger egg-masses than the snails fed with fish food at about $26^{\circ}C$. Under conditions of continuous activity and growth, the maximum expectation of life appears to be 109~350(mean 230) days. And the shell length of snails at death were 1.39~1.64cm.

• 한국발생생물학회지:발생과생식
• /
• 제21권3호
• /
• pp.287-295
• /
• 2017

This study was conducted to observe egg and larvae morphological development of carp to obtain basic data for resource conservation and taxonomic research. Brood carp used in the research (total length 67.3-75.5 cm, average $71.0{\pm}3.45cm$) were bred in a circular rearing aquarium ($600{\times}300{\times}100cm$) using a running water system from January to July, 2015. Breeding water temperature was maintained at $23.0-25.0^{\circ}C$(average $24.0^{\circ}C$). Fertilized carp eggs were translucent and globular, and their size was 1.75-1.89 mm (average $1.82{\pm}0.06mm$). Blastoderms formed 10 min after fertilization and reached the two-cell stage 30 min after fertilization. Then, the embryo turned dark and exhibited melanophores, and blood started flowing from the heart across the egg yolk at 42 hrs and 50 min after fertilization. Hatching began 70 hrs and 26 min after fertilization larvae emerged through the egg membrane, starting from the head. The length of prelarvae immediately after hatching was 5.23-5.38 mm (average $5.31{\pm}0.11mm$) the mouth and anus were closed, and the pectoral fin was formed. Postlarvae at 18 days after hatching had a total length of 11.9-13.9 mm (average $12.9{\pm}1.40mm$), separate anal fin and back membranes, and fin ray. Juveniles fish at 35 days after hatching had a total length of 29.9-30.2 mm (average $30.1{\pm}0.13mm$), with the body covered with scales, and the same number of fin rays, color, and shape as their broodstork.

• Journal of Microbiology and Biotechnology
• /
• 제12권6호
• /
• pp.865-871
• /
• 2002

A bacterium having strong chitinolytic activity on $0.2\%$ colloidal chitin-containing agar medium was isolated from coastal soil in Korea. Based on the nucleotide sequence of conserved segment of a 165 rRNA gene, the bacterium was identified as Paenibacillus illinoisensis KJA-424. The population of P. illinoisensis KJA-424 and chitinase activity significantly increased for the first 2 days of incubation. On SDS-PACE analysis with $0.01\%$ glycol chitin, three protein bands (63, 54, and 38 kDa) with chitinolytic activity were detected tooted. The effect of P illinoisensis KJA-424 on the egg hatch of root-knot nematode (Meloidogyne incognita) was investigated. After 7 days of incubation with the chitinase-producing P. illinoisensis KJA-424, none of the eggs hatched, whereas a $39.8\%$ egg hatching rate was observed in the water control. Inverted and scanning electron microscopic observations demonstrated that P. illinoisensis KJA-424 deformed and destroyed the eggshell of M. incognita. In conclusion, chitinase-produced by p. illinoisensis KJA-424 caused the lysis of M. incognita eggshell and resulted in the inhibition of egg hatching in vitro.

• 생명과학회지
• /
• 제13권1호
• /
• pp.34-41
• /
• 2003

The hatching of fertilized egg and early development of larval black seabream, Acanthopngrus schlegeli by immersion of 3,5,3'-triiodo-L-thyronine ($T_3$) with doses of 0.01~0.5 ppm in tank were examined for early development periods and compared with control fish immersed by 0.1 N NaOH and 99% alcohol. Larvae were fed with rotifers for first 5 days during experimental period. Yolk absorption of larvae from $T_3$ immersion groups were significantly faster than that of control. Although hatching times among each groups were not significant difference. the hatching rates of larvae in higher doses (0.1 ppm and 0.5 ppm $T_3$ groups) were significantly lower than control. The results of $T_3$ immersion experiments to newly hatching larvae indicated that exogenous $T_3$induced significant faster the absorption of yolk and oil globule, faster the development of myotome and digestive duct and higher the growth rate of larvae than larvae of control. These results indicate that $T_3$ immersion supplements appear to confer a distinct advantage to eggs and larvae of black seabream, which is in early fragile developmental stage.

• 한국발생생물학회지:발생과생식
• /
• 제23권2호
• /
• pp.161-170
• /
• 2019

The purpose of this study is to investigate the development of Coreoleuciscus splendidus egg and larvae morphology in the Ungcheon-stream. C. splendidus eggs were round and ranged in size from 1.86-2.01 mm (mean $1.91{\pm}0.14mm$). Immediately after hatching, the larvae had egg yolk in the abdomen with a total length of 5.27-6.63 mm (mean $5.95{\pm}0.96mm$). On the 10 days after hatching, the latter was 8.44-8.65 mm (mean $8.54{\pm}0.14mm$) in total length, and 5 dorsal fin rays were formed in dorsal fin and 8 caudal fin soft rays were formed in caudal fin. At 88 days after hatching, total length was 26.2-25.7 mm (mean $25.9{\pm}0.35mm$), and scales were formed throughout the body. The fin rays of each part were iii.7 in dorsal fin and iii.6 in anal fin, and finally the external form was the same as the adult fish.

• 한국수산과학회지
• /
• 제55권1호
• /
• pp.23-29
• /
• 2022

This study was carried out to clarify the egg, larvae and juveniles development of Misgurnus anguillicaudatus, and relationships of M. anguillicaudatus and M. mizolepis, Cobitididae Fishes. The adult fishes were collected in Samsan-cheon, Haenam-gun, Jeollanam-do, Korea and their spawning inducement was carried by ovaprim injections. The egg shape was circular and the size was average 1.12 mm. The eggs were hatched at 61 to 72 h after fertilization. The newly hatched larvae had an average 3.23 mm in total length (TL). At 5 days after hatching, the larvae reached to post larval stage and they were 10.3 mm in TL. At 19 days after hatching, it reached to juvenile stage and was 25.3 mm in TL. The egg size of M. anguillicaudatus was almost same as M. mizolepis but the hatching period of M. anguillicaudatus has taken longer. It was possible for interspecific distinguishability of M. anguillicaudatus and M. mizolepis when their larvae reached to juvenile stage by the development of keel-like ridges.